Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
Carlo Santoro, Alexey Serov, Claudia W. Narvaez Villarrubia et al.
Scientific Reports · 2015
Abstract For the first time, a new generation of innovative non-platinum group metal catalysts based on iron and aminoantipyrine as precursor (Fe-AAPyr) has been utilized in a membraneless single-chamber microbial fuel cell (SCMFC) running on wastewater. Fe-AAPyr was used as an oxygen reduction catalyst in a passive gas-diffusion cathode and implemented in SCMFC design. This catalyst demonstrated better performance than platinum (Pt) during screening in “clean” conditions (PBS) and no degradation in performance during the operation in wastewater. The maximum power density generated by the SCMFC with Fe-AAPyr was 167 ± 6 μW cm −2 and remained stable over 16 days, while SCMFC with Pt decreased to 113 ± 4 μW cm −2 by day 13, achieving similar values of an activated carbon based cathode. The presence of S 2− and "Equation missing"<!-- image only, no MathML or LaTex -->showed insignificant decrease of ORR activity for the Fe-AAPyr. The reported results clearly demonstrate that Fe-AAPyr can be utilized in MFCs under the harsh conditions of wastewater.
Wilgince Apollon, Juan Vidales-Contreras, Humberto Rodríguez-Fuentes et al.
Energies · 2022
Plant microbial fuel cells (P-MFCs) are sustainable and eco-friendly technologies, which use plant root exudates to directly nourish the electrochemically active bacteria (EABs) to generate sustainable electricity. However, their use in evaluating plant growth has been insufficiently studied. In this study, interconnection between plant growth and the production of bioelectricity was evaluated by using P-MFCs inoculated with 642.865 mL ≅ 643 mL of livestock’s urine such as cow urine, goat urine, and sheep urine. The greatest mean stem diameter of 0.52 ± 0.01 cm was found in P-MFC-3 inoculated with goat urine, while the P-MFC-2 treated with cow urine reached a higher average number of roots with a value of 86 ± 2.50 (95% improvement) (p < 0.05). Besides, P-MFC-4 presented greater height of 50.08 ± 0.67 cm. For polarization curve experiment a higher maximum power density of 132 ± 11.6 mW m−2 (931 mA m−2) was reached with cow urine; in turn, with regard to the long-term operation, the same reactor indicated a higher maximum average power density of 43.68 ± 3.05 mW m−2. The study’s findings indicated that Stevia P-MFC inoculated with urine was a good option to increase the biomass amount for the agricultural plants along with power generation. Further, this study opens the way for more investigation of evaluating the impact of P-MFC on plant growth.
Margaret. A. Adekanle, Julius K. Oloke, O. Catherine Adekunle et al.
Global Journal of Pure and Applied Sciences · 2020
Power supply has remained a challeng issue in developing coutries. The aim of this study was to evaluate the potentials of selected yeast species for bioelectricity generation. Different yeast species were isolated from cassava wastewater, whey wastewater, human urine, and rabbit dung using the spread plate method. These isolates were identified using analytical profile index (API). Results obtained revealed the identity of the isolated yeast species as Candida famata, Candida hellenical. Candida tropicalis and Saccharomyces cerevisia (using API method).The isolated yeast species were used singly, and as a consortium for bioelectricity generation, and yeast in continuous mode. The same wastes as used for the isolation process were evaluated as possible substrates for the generation of bioelectricity. Out of the four wastes used, cassava processing wastewater gave the highest bioelectricity potential and was subsequently used as substrate for further study. Saccharomyces cerevisiae elicited the highest electricity generation when the four yeast species were used singly (1.08V). A consortium of the four isolates elicited a synergis effect, generating 1.57V of voltage. Stacking of the Microbial Fuel Cell(MFC) components improved voltage to 2.4V due to its lower internal resistance within the stacked materials. It is apparent from the results obtained in this study that when properly harnessed, microbial fuel cells (MFCs) technology could serve as alternate source of renewable energy.
 Keywords: Microbial fuel cells, Waste, yeasts, Salt- Bridge, Nafion117.
Catalina González-Nava, Michel Canul-Chan, Juan Campos et al.
Revista Internacional de Contaminación Ambiental · 2024
Microbial fuel cells (MFC) constitute an attractive alternative as an environmental remediation technology since they can generate electrical current using organic waste as a substrate. Since the performance of MFCs depends on the characteristics of the biofilm on the anode surface, it is important to assess the genetic information of the microorganisms that grow on the electrode. For this purpose, a sewage sludge sample was obtained from a wastewater treatment plant and used to inoculate a type H MFC. Electrochemical characterization, on one hand, indicates that while the biofilm has a typical electrochemical performance reflected by the generated voltage (near 0.4 V) and by the electroactivity observed in cyclic voltammetry experiments, and on the other hand, the metagenomic analysis shows that the most abundant genera are Pseudomonacea, Nitrosomonas, Hyphomonas, and Opitutus. The study also indicates that the biofilm’s electroactive microorganisms can metabolize amino acids, lipids, and carbohydrates and possess genetic tools for ionic transport and energy production. Regarding the electron acceptor/donator capabilities, several oxidases, reductases, and complexes were identified, mainly terminal cytochrome C oxidase and respiratory complex I, which could be associated with the exoelectrogenic capacity of the microorganisms. Finally, the metagenomic information indicates that the biofilm can synthesize rhamnose, sialic acid, and alginate molecules, which could possibly be associated with the formation and consolidation of the microbial biofilm.
Teng Howe Cheng, Kok Boon Ching, Chessda Uttraphan et al.
Indonesian Journal of Electrical Engineering and Computer Science · 2020
Plant microbial fuel cell (P-MFC) is an electrochemical reactor that converts organic compounds to electrical energy through the catalytic reaction from electrochemically active bacteria (EAB). However, there is no sign of an attempt in developing the functional model in predicting the energy conversion and utilization of P-MFC. In this study, an analytic model is proposed to show the whole production process of the organic compound to electrical energy generation. <em>Pandanus Amaryllifolius</em> plant was used as sources of photosynthate, where biomass product from rhizodeposition, acetate was produced, and soil bacteria as the microbial culture, and air as the input to the cathode chamber. The proposed analytical model is able to predict the output of the P-MFC using the parameters from the experiment. The generated data from the model was then compared with the monitored data from the <em>Pandanus Amaryllifolius </em>P-MFC. The results show the electrical power output has a high similarity pattern with the bacterial growth curve model and able to achieve the coulombic efficiency of 95.32%.
K. Sathish Kumar, Omar Solorza-Feria, G. Vázquez-Huerta et al.
ECS Transactions · 2011
Anode-respiring bacteria (ARB) perform an unusual form of respiration in which their electron acceptor is a solid anode. The focus of this study was to characterize the electrical stress direct evolution of biocatalysts as a way of enriching the community with ARB for microbial fuel cell. We gave the electrical stress continually to the Texcoco bacterial community at -150mV/SCE. The 4th day current started to increase and attained the maximum current of 0.35mA in the 15 th day. The current in this period was associated to biofilm growth. On the 15thday and by using cyclic voltammetery, an irreversible electron transfer reaction of alkaliphilic cytochrome was found, due to the electrode fouling. From the impedance measurement, the biofilm ARB resistance was determined (~250Ω). Further confocal microscopy studies of biofilm ARB revealed ~6µm thickness. In the single chamber microbial fuel cell, the electrochemical stressed biofilm-ARB exhibited a maximum power density of 79mW/m2
B. Li, Z. Zhao, Z. Weng et al.
Fuel Cells · 2020
Abstract To boost the performance of microbial fuel cells (MFCs), a novel material of polypyrrole nanowires (PPy‐NWs) modified by carbon dots (CDs) is synthesized by polymerizing pyrrole monomers and CDs, in which CDs are attached and distributed on the surface of the PPy‐NWs, thus leading to the rough surface with a special dot‐line structure. Such CDs/PPy‐NW composite with special unique structure exhibits superior properties, and excellent performance is found for MFC using CDs/PPy‐NW composite as anode. The electron transfer rate increases to 0.0934 s −1 with a sharp rise by 26% over pure PPy‐NWs, and the resistances of CDs/PPy‐NW electrode are only one third of those of pure PPy‐NWs electrode. Further, the mini‐MFC equipped with the CDs/PPy‐NW composite as anode exhibits a high open circuit voltage (630 mV) and its maximum power density with a value of 291.4 mW m −2 is twice that of the mini‐MFC equipped with pure PPy‐NWs anode. These results demonstrate CDs/PPy‐NW with a unique dot‐line structure as a more promising anode material for MFC application.
Pingying Zeng, Kang Wang, Ryan Falkenstein-Smith et al.
ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology · 2014
This study examines the successful development of a combustion-driven thermal transpiration-based combustor and a self-sustaining gas pump system having no moving parts and using readily storable hydrocarbon fuel. A stacked configuration was then integrated into the combustor creating a self-sustaining power generation system. In recent years, power generation devices employing hydrocarbon fuels rather than electrochemical storage as energy feedstock have been studied extensively due to the much higher energy densities of hydrocarbon fuels than the best available batteries. While many devices have been proposed including internal combustion engines and gas turbines, they all require the use of air to obtain a higher energy density so that only one reactant (fuel) need be carried. Thermal transpiration was accomplished by meeting two essential conditions: (1) gas flow in the transitional or molecular regime using glass microfiber filters as transpiration membranes and (2) a temperature gradient through the membrane using catalytic combustion downstream of the membrane. A cubic combustor was designed to house the thermal transpiration membrane and develop into a self-sustaining gas pump system. Fuel/Air would feed through an inlet into a mixing chamber that would flow into the thermal guard containing the thermal transpiration membrane. The thermal guard was developed from a high thermal conductivity stainless steel made into a cubic formation by using a 3D printing process. This configuration allowed both fuel and air to be transpired through the membrane meaning it was not possible for any reactant flow to occur as a result of the fuel supply pressure and only the membrane could draw reactants into the device. In addition to pumping, a single-chamber solid-oxide fuel cell (SC-SOFC) was incorporated into combustion driven thermal transpiration pumps to convert chemical or thermal energy into electrical energy for a self-contained portable power generation system. Experiments showed that transpiration pumps with larger porosity and larger overall size exhibited better performance, though membrane pore size had little effect. These results were quantitatively consistent with theoretical predictions. By exploiting the temperature and fuel/oxygen concentrations within the transpiration pump, the SOFC achieved a maximum power density of 40 mW/cm2. Despite being far lower than necessary for a power source to be competitive with batteries, this preliminary study signifies an on-going positive efficiency that has potential for improvement through optimizing SOFC technology.
Sona Kazemi, Madjid Mohseni, Khalid Fatih
Journal of Chemical Technology & Biotechnology · 2014
Abstract BACKGROUND High cost and ohmic loss are two issues that microbial fuel cells ( MFC ) face before becoming economically viable. To address the high cost and ohmic loss issues, a flat‐plate MFC ( FPMFC ) configuration applying a passive air‐breathing cathode and a three‐dimensional anode was introduced. Electricity generation was examined in the FPMFC through operation in the presence and absence of a proton exchange membrane ( PEM ), and in batch and continuous modes. RESULTS Continuous operation of the FPMFC in the presence of a PEM favored power generation, mainly due to elimination of oxygen and biomass in the anode. Peak power density of 18 Wm ‐3 was produced in the presence of a PEM (ohmic resistance 40 Ω cm 2 ), which was more than 5‐fold higher than that with J‐cloth. During batch operation, the power density increased and reached maximum in the third batch (18 W m ‐3 at 60 A m ‐3 ). Greater stability was observed during continuous operation resulting in a 2.5‐fold increase in peak power density (44 W m ‐3 at 146 A m ‐3 ). CONCLUSION The passive air‐breathing FPMFC showed promising performance, offering a more economically viable configuration than the conventional FPMFCs using active (air, ferricyanide, and ferric iron) cathodes. © 2014 Crown copyright. Journal of Chemical Technology & Biotechnology © 2014 Society of Chemical Industry
Sun-Joon Byun, Zhen Huan Wang, Jun Son et al.
Preprints.org · 2017
We propose a wave-like design on the surface of cathode channels (wave form cathode channels) to improve oxidant delivery to gas diffusion layers (GDLs) [1-2]. We performed experiments using PEMFCs combined with wave form surface design on cathodes. We varied the factors of the distance between wave-bumps (the Adhesive distance, AD), and the size of the wave-bumps (the Expansion ratio, ER). The ADs are 3, 4, and 5 times the size of the half-circle bump&rsquo;s radius, and the ERs are 1/1.5, 1/2, and 1/3 times the channel&rsquo;s height. We evaluated the performances of the fuel cells, and compared the current-voltage (I-V) relations. For comparison, we prepared PEMFCs with conventional flat-surfaced oxygen channels. Our aim in this work is to identify fuel cell operation by modifying the surface design of channels, and ultimately to find the optimal design of cathode channels that will maximize fuel cell performance.
Johanna Dombrovskis, Victor Shokhen, Lisa Kylhammar et al.
ECS Meeting Abstracts · 2024
The fuel cell market is maturing, and the production volumes are increasing. In parallel, expectations on performance, lifetime and operational range for fuel cell stacks are growing. As fuel cell technology matures, more fuel cell stacks are used in real life applications instead of laboratory environment. These positive developments bring with them new challenges and opportunities to learn. Several of these challenges and their impact on stack design and validation will be discussed. The focus will be on optimization of useful stack power density, fuel cell stack conditioning, enlarging the LT-PEM fuel cell operation range and on durability testing. This talk addresses why conditioning and durability testing are closely connected and illustrates how this can impact stack platform and fuel cell development. In addition, the interactions between power density, stack integration and stack operational window are illustrated showing how each of these parameters could be optimized utilizing a current distribution plate and what trade-offs are relevant for optimized fuel cell stack and system performance. Powercell is active in various market segments and has developed stacks and stack components for ~20 years. The optimizations and trade-offs described hinge heavily on key PEM stack requirements which can be widely different in different PEM fuel cell market sectors, as illustrated by the emerging usage of fuel cells in aviation.
S. Mateo, A. Gonzalez del Campo, J. Lobato et al.
Biotechnology Progress · 2016
In this work, the long‐term effects of transient chemical oxygen demands (COD) concentrations over the performance of a microbial fuel cell were studied. From the obtained results, it was observed that the repetitive change in the COD loading rate during 12 h conditioned the behavior of the system during periods of up to 7 days. The main modifications were the enhancement of the COD consumption rate and the exerted current. These enhancements yielded increasing Coulombic efficiencies (CEs) when working with COD concentrations of 300 mg/L, but constant CEs when working with COD concentrations from 900 to 1800 mg/L. This effect could be explained by the higher affinity for the substrate of Geobacter than that of the nonelectrogenic organisms such as Clostridia . © 2016 American Institute of Chemical Engineers Biotechnol. Prog. , 32:883–890, 2016
Z. Fu, K. Li, L. Pu et al.
Fuel Cells · 2016
Abstract One of the main limiting factors for scaling up microbial fuel cells (MFCs) technology is to develop low‐cost and high‐efficiency cathode. A new and simplified approach was developed by using a commercial waterproof breathable membrane (WBM) as gas diffusion layer (GDL) material as substitution for conventional polytetrafluoroethylene (PTFE) GDL. Air‐cathode with the WBM pasted (AC‐P) onto the stainless steel mesh (SSM) achieved a maximum power density of 611 ± 10 mWm −2 , which was similar to that using a PTFE GDL by rolling method (645 ± 12 mWm −2 , AC‐R). Physical and electrochemical techniques were employed to investigate the morphology and electrochemical characteristics of the cathode. The result demonstrated that AC‐P had a higher current density and internal resistance than AC‐R. Besides, the WBM had a higher porosity and uniform texture. The study showed that the WBM was a kind of good GDL material for easy preparation, low cost and stable performance of cathode construction.
Sadiq Haruna, Hindatu Yusuf, Ahmad Muhammed Gumel et al.
Dutse Journal of Pure and Applied Sciences · 2024
Microbial fuel cells (MFCs) have shown promise as a sustainable technology for wastewater treatment and energy recovery. In this study, cattle dung was used as an inoculum and kitchen waste (KW) from Dutse urban, Nigeria was used as a substrate for bioelectricity generation in MFC. The MFC was operated in a fed-batch mode over 37 days, spanning three cycles. During characterization, the chemical oxygen demand (COD) of the KW was found to be 30421 ± 124 mg/L, indicating a high concentration of organic pollutants. The MFC's performance was evaluated based on the voltage generated, with the first cycle reaching a peak of 254 mV, the second cycle 247 mV, and the third cycle 242 mV. Current and power densities during the three cycles decreased gradually from 66.84 mA/m² and 16.84 mW/m² in the first cycle to 63.68 mA/m² and 15.41 mW/m² in the third cycle respectively. Furthermore, there was a notable reduction in COD from the influent diluted from initial measured COD, from 1120 ± 63 mg/L to an effluent level of 226 ± 49 mg/L, indicating approximately 80% removal rate. The pH of the anolyte progressively dropped with each cycle, reflecting the metabolic activities of bacteria in the anode chamber. The findings underscore MFC's potential for organic waste management and electricity generation, with results outperforming some contemporary studies.
Xiuwei Fu, Li Fu, Hashem Imani Marrani
Journal of New Materials for Electrochemical Systems · 2021
The microbial fuel cell is one of the most important tools in the supply of renewable energy and its controller plays an important role in improving the performance and stability of its output. Using the advantages of adaptive and sliding mode methods, this paper presents a combined technique to ensure the stability and output voltage stabilization of the fuel cell in the presence of parametric uncertainties and nonlinear terms. The proposed control method is compared with classical control approaches and the simulation results confirm its efficiency.
Victoria Marie Ehlinger, Ahmet Kusoglu, Adam Z. Weber
ECS Meeting Abstracts · 2019
Throughout the lifetime of a polymer-electrolyte fuel cell, the membrane undergoes chemical degradation that causes defects to form and grow, contributes to a loss of performance, and can lead to cell failure. A combination of accelerated stress tests (ASTs) 1-2 and modeling studies 3-4 have been performed on this topic to better understand membrane degradation mechanisms and how to mitigate them 5-6 . During fuel-cell operation, formed peroxide radicals due to reactant gas crossover attack the polymer backbone and end chains, leading to membrane thinning and formation and growth of defects such as cracks and pinholes. This study builds upon our previous modeling study on membrane degradation to analyze the addition of chemical scavengers into the fuel-cell membrane to mitigate the effects of chemical degradation via radical attack. The developed model is transient and 1D across the fuel-cell sandwich. The transport and concentration of cerium is modeled using an ion-transport model based on concentration solution theory, thereby allowing the evaluation of how water gradients also move cerium ions throughout the ionomer, resulting in nonintuitive distributions. The model results also show how drive-cycle testing impacts the performance of the cell and the location of cerium, where relaxation of the applied gradients help redistribute the cerium in the ionomer. The purpose of the study is to optimize the cerium amount in both the membrane and catalyst layers by balancing effects of mitigation of chemical degradation and performance due to the impact of cerium on the ionomer material properties. For the latter, a key feature is accounting for the nonlinearities induced by the impacts of cerium on membrane and catalyst-layer ionomer properties. Acknowledgements The authors would like to thank Hans Johansen for helpful discussions and Los Alamos National Laboratory for providing material property data. Funding support was supplied by the Fuel Cell Performance and Durability Consortium (FC-PAD), by the Fuel Cell Technologies Office (FCTO), Office of Energy Efficiency and Renewable Energy (EERE), of the U.S. Department of Energy under contract number DE-AC02-05CH11231. References R. Borup, et al., Chem. Rev. , 107 , 3904 (2007) F. A. de Bruijn, et al., Fuel Cells , 8 , 3 (2008). R. Singh, et al., J. Electrochem. Soc. , 165 , F3328 (2018) K. H. Wong and E. Kjeang, J. Electrochem. Soc. , 166 , F128 (2019). M. Zatón, et al., Sustainable Energy & Fuels , 1 , 409 (2017). F. D. Coms, et al., in The Chemistry of Membranes Used in Fuel Cells: Degradation and Stabilization , 1st ed., S. Schlick Editor, John Wiley & Sons, Inc. (2018).
Simona Di Micco, Pasquale De Falco, Mariagiovanna Minutillo et al.
E3S Web of Conferences · 2021
Microbial fuel cells (MFCs) are playing an important role in the context of sustainable energy development. They represent a sustainable approach to harvest electricity from biodegradable materials. However, harvesting energy from MFCs represents a critical issue because of the low output voltage and power produced. Realizing stacked configurations may involve an increase in MFCs performances in terms of output voltage, current and electric power. In this paper, two stacked configurations under different electrical connection modes have been designed, developed, modeled and tested. The stacked MFCs consist of 4 reactors (28 mL x4) that are connected in series, and parallel-series modes. Three different tests have been carried out, which involves: 1) performing the polarization and power curves by applying decreasing resistances; 2) assessment of the electric behavior of each reactor over time at a fixed resistance, 3) performing the polarization and power curves by applying increasing resistances. Moreover, a numerical model for predicting the transient behavior of the electrical quantities for one reactor, has been developed and validated by using the experimental data. As expected, the results highlighted that the parallel-series configuration assures the highest volumetric power density compared to the series configuration, reaching the maximum value of 1248.5 mW/m 3 (139.8 µW) at 0.291 mA. Eventually, by comparing the numerical and the experimental data, it has been demonstrated that the developed model is able to predict the reactor’s electrical trend with a good accuracy.
Atsushi Aoki, Akebono Tanaka
ECS Meeting Abstracts · 2018
Organic light emitting diodes (OLED) have been greatly investigated for application in flat panel display and light source. A different type of OLED is light emitting electrochemical cell (LEC), which consists of luminescent chromophore films with solid electrolyte such as ionic ruthenium complex film. Driving process of LEC is different from that of OLED. That is, upon applied voltage, the electric double layer is formed at the interface between the anode or cathode and ionic luminescent film and hole and electron are injected from both electrodes into the luminescent film and then light is emitted by charge recombination. Thus, LEC has attractive features which are single-layer device and no requirement to use low work function metal as a cathode. However, LEC has some drawback which is ill charge-injection balance between hole and electron caused by the difference in ion size between large ruthenium complex cation and small counter anion. To improve the charge-injection balance, incorporation of small cation into ionic luminescent layer will be expected. In this study, current efficiency for LEC was improved by introduction of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as additive electrolyte into the ruthenium complex film of LEC. LEC was prepared by spin-coating tris(2,2’-bipyridyl) ruthenium(II) complex TFSI 2 (Ru(bpy) 3 (TFSI) 2 ) and poly(methyl methacrylate) (PMMA) matrix in acetonitrile solution with LiTFSI solid electrolyte on ITO anodes. And then silver was vacuum-deposited onto the resulting ruthenium complex film with solid electrolyte on ITO anodes. The luminescent property of LEC was performed by applying constant current. The standard LEC without LiTFSI was not emitted and the lower voltage than 1 V was observed in the constant current of smaller than 1.5 mA whereas it was emitted and the voltage of around 2.5 V was observed in the constant current of larger than 1.5 mA. These results indicate that the only hole injection occurs and the electron injection does not occur until the applied current over 1.5 mA. It’s due to the thicker electric double layer of ruthenium complex at the cathode of LEC. As introduction of LiTFSI into the ionic luminescent layer, the emission starts at the smaller applied current with increasing amount of LiTFSI. The maximum current efficiency becomes 3.0 cd/A in the LEC containing 3 wt% LiTFSI. However, the addition of more than 3 wt% LiTFSI into LEC makes LEC performance worse because the distance between ruthenium complex become wide and the electron hopping rate becomes slow. Finally, addition of 10 wt% LiTFSI makes crystalize ionic luminescent layer and it does not function as LEC. Therefore, we found that the introduction of 3 wt% LiTFSI to LEC was the optimum condition.
Ignacio T. Vargas, Natalia Tapia, John M. Regan
Materials · 2022
During the last decade, bioprospecting for electrochemically active bacteria has included the search for new sources of inoculum for microbial fuel cells (MFCs). However, concerning power and current production, a Geobacter-dominated mixed microbial community derived from a wastewater inoculum remains the standard. On the other hand, cathode performance is still one of the main limitations for MFCs, and the enrichment of a beneficial cathodic biofilm emerges as an alternative to increase its performance. Glucose-fed air-cathode reactors inoculated with a rumen-fluid enrichment and wastewater showed higher power densities and soluble chemical oxygen demand (sCOD) removal (Pmax = 824.5 mWm−2; ΔsCOD = 96.1%) than reactors inoculated only with wastewater (Pmax = 634.1 mWm−2; ΔsCOD = 91.7%). Identical anode but different cathode potentials suggest that differences in performance were due to the cathode. Pyrosequencing analysis showed no significant differences between the anodic community structures derived from both inocula but increased relative abundances of Azoarcus and Victivallis species in the cathodic rumen enrichment. Results suggest that this rarely used inoculum for single-chamber MFCs contributed to cathodic biofilm improvements with no anodic biofilm effects.
Tejas Ambekar
International Journal for Research in Applied Science and Engineering Technology · 2022
Abstract: This work aims towards the simulation of Various proton exchange membrane fuel cell (PEMFC) models to investigate the effects of operating parameters such as temperature, pressure, anode flow levels and cathode reactants, component types, cooling temperatures in the performance of a modified fuel cell. The basic model and the tubular model are developed in modelling software based on the size of the parameter later simulated using the addon module in the Ansys software. The Addon module is specifically designed to mimic a different type of fuel cell. The simulated model of cell power output showed positive compliance with experimental results taken from the literature and revealed that the operating pressure, temperature, and flow rate of reactants positively affect the function of the Fuel cell. The results also showed that the cooling temperature of the coolant indicates higher concentrations of current congestion compared to the base model without cooling. Corrective results obtained from the effect of temperature on cell function showed that the fuel cell temperature favor both cell function and efficiency. It can therefore be assumed that the efficiency of the cell is strongly influenced by operating temperature, pressure, cooling temperature, fuel flow rate and oxidant. Keywords: PEM fuel cell, Current density, tubular fuel cell, addon-module.
Kalagbor IA
Open Access Journal of Waste Management & Xenobiotics · 2019
Green Chemistry is gaining prominence in environmental and technological processes. Generating electricity from agro wastes comprising of waste vegetables and fruits are new sources of clean energy. Scientists need to develop technological methods of converting these agro wastes to useful resources especially in developing countries. Fruit wastes are generated in large quantities globally from processing plants. Defective tomatoes rejected and damaged banana fruits as well as unusable pineapple fruits and peels constitute part of the agro waste biomass generated annually. Effective management of this biomass is still ongoing. This research focuses on the conversion of these agro wastes to bioelectricity (green energy) using single microbial fuel cells (SMFCs) technology. Fruits wastes of 5kg, 10kg, 15kg and 20k were used. Results showed that the higher the quantity of substrate, the higher the electricity produced. The maximum voltage outputs generated on day 1 were 4.2V, 3.1V and 3.0V from tomatoes, banana and pineapple (fruit and peel) wastes respectively. The values obtained for current readings were significantly proportional to the voltage readings. The physiochemical parameters; pH, Conductivity, BOD, COD and DO were consistent with those from similar studies. The conversion of tomatoes, banana and pineapple fruit waste to bioelectricity was achieved. Reduction of this biomass by biodegradation using the SMFC technology is one way of removing these agro wastes from the ecosystem to maintain a clean, healthy, pollution-free environment.
Mirella Di Lorenzo, Tom P. Curtis, Ian M. Head et al.
Water Science and Technology · 2009
This study reports an investigation of the effect of the anode surface area on the performance of a single chamber microbial fuel cell (SCMFC) based biosensor for measuring the organic content of wastewater. A packed bed of graphite granules was used as the anode. The surface area of the anode was changed by altering the granule bed thickness (0.3 cm and 1 cm). The anode surface area was found to play a role in the dynamic response of the system. For a granule bed thickness of 1 cm and with an external resistance of 500 Ω, the response time (defined as the time required to achieve 95% of the steady-state current) was reduced by approximately 65% in comparison to a SCMFC biosensor with a carbon cloth anode.
Subha Chandrasekarabarathi, Priya ArunKumar, Rajesh Banu Jeyakumar
Environmental Progress & Sustainable Energy · 2023
Abstract Microbial fuel cells (MFC) are recent advancements in treating wastewater and generating power simultaneously. In the present study, chocolaterie wastewater rich in organic content was the substrate in a dual‐chambered MFC. Activated Carbon Fiber Felt (ACFF) electrodes (anode and cathode) were separated by Nafion 117 proton exchange membrane in the dual‐chambered reactor. The primary goal was to investigate the impact of organic loading on MFC efficiency in treating chocolaterie wastewater and carrying out microbial analysis. 1, 2, 3, and 4 gCOD/L were the organic loadings of the reactor. MFC performance increased till the optimum value, and after that, it declined. A total of 2 gCOD/L was the optimum organic loading. At this optimum organic loading, dual‐chambered MFC removed 79% of total chemical oxygen demand (TCOD), 70% of soluble chemical oxygen demand (SCOD), and 67% of total suspended solids (TSS). At 2 gCOD/L organic loading, the maximum power density was 99 mW/m 2 . Coulombic efficiency was 58% at 1 gCOD/L and 30% at 2 gCOD/L organic loadings. Microbial analysis revealed the presence of Ochrobactrum and Pseudomonas sp. as dominant exoelectrogens in the anodic biofilm. These species were proven for the contaminant degradation efficiency and potential for power generation. Hence dual‐chambered MFCs can treat high‐strength chocolaterie wastewaters efficiently at optimum operating conditions.
Samindi Madhubha Jayawickrama, Tsuyohiko Fujigaya
ECS Meeting Abstracts · 2019
Polymer electrolyte membrane fuel cells (PEMFCs) have been receiving ample attention as an efficient and clean power source for stationary and automotive applications. 1 One of the challenges for commercialization of PEMFCs is to minimize the amount of Platinum (Pt) to lower the cost of PEMFC. Pt is the most stable and active catalyst for oxygen reduction reaction (ORR). 2 Incorporation of non-precious metals and decreasing the catalyst particle size are common methods to reduce the amount of Pt used in PEMFC. However, these methods involve dissolution of non-precious metals in acidic condition 3 and agglomeration of small sized Pt 4 , resulting in decreased Pt utilization. Therefore, improvement of Pt utilization efficiency is required. Optimizing catalyst structure by increasing number of reaction sites is a promising strategy to improve the Pt utilization efficiency. One approach is increasing mass diffusion (oxygen, proton) by selecting a non-porous carbon support like acetylene black (AB). 5 However, Pt durability and utilization are limited due to lack of anchoring sites for Pt particles in AB. 6 Another approach is optimizing ionomer/carbon ratio. However, recent high-resolution transmission electron microscopy studies suggest that the ionomer coverage in the electrode may be rather inhomogeneous. 7 In this study, we demonstrate a novel approach to improve Pt utilization efficiency in PEMFC by preventing deposition of Pt particles into interior pores of carbon support and simultaneously providing homogeneous ionomer; Nafion coverage. This approach involves polymer coating onto carbon blacks (CBs). Polybenzimidazole (PBI) is used as the surface coating material of CB where PBI interacts with CB via π-π and acid-base interactions. It is reported that PBI coating works as the micropore capping agent of CB. 8 Therefore, PBI coating can reduce number of Pt particles deposited into geometrically restricted areas of CB. Moreover, PBI coating may trigger a homogeneous Nafion coverage due to the acid-base interaction between Nafion and PBI concurrently. Three morphologically different CBs; Vulcan, Ketjen black (KB) and AB were used to investigate the Pt utilization efficiency in polymer coated CBs. The PBI coating onto CB was easily done by addition of CB into PBI dissolved N,N -dimethylacetamide and 1 hr sonication to the mixture to prepare Vulcan/PBI, KB/PBI and AB/PBI. Then Pt nano-particles were deposited via polyol reduction to prepare Vulcan/PBI/Pt, KB/PBI/Pt and AB/PBI/Pt and compared with their non-coated Vulcan/Pt, KB/Pt and AB/Pt. AB/PBI/Pt shows homogeneous Pt dispersion over AB/Pt due to the presence of binding sites through coordination of Pt with imidazole groups in PBI as an additional advantage. The micropore density of CBs is increasing in the order of AB < Vulcan < KB. Power density of CB/Pts was decreased in the following order; AB/Pt < Vulcan/Pt < KB/Pt, consistent with the order of increasing micropore density. The lower performance of KB/Pt is due to the decreased number of accessible Pts for the electrochemical reaction especially for ORR 5 . Interestingly, power densities of CB/PBI/Pts were higher than that of respective CB/Pts. The higher power density of CB/PBI/Pt can be attributed to the reduced inaccessible amount of Pt deposited into the micropores of CB and the reduced protonic resistance in the catalyst layer due to the homogeneous Nafion layer. 9 Furthermore, power densities of CB/PBI/Pts were increasing in the order of KB/PBI/Pt < Vulcan/PBI/Pt < AB/PBI/Pt. The highest performance of AB/PBI/Pt is believed to be due to lower mass transfer limitation in the catalyst layer which is caused by the lower pore density of AB/PBI along with the uniform Nafion coverage. References Kibsgaard, J.; Gorlin, Y.; Chen, Z.; Jaramillo, T. F., J. Am. Chem. Soc. 2012, 134 , 7758. Nørskov, J. K.; Rossmeisl, J.; Logadottir, A.; Lindqvist, L.; Kitchin, J. R.; Bligaard, T.; Jónsson, H., J. Phys. Chem. B 2004, 108 , 17886. Colón-Mercado, H. R.; Kim, H.; Popov, B. N., Electrochem. Commun . 2004 , 6 , 795. Tang, L.; Han, B.; Persson, K.; Friesen, C.; He, T.; Sieradzki, K.; Ceder, G., J. Am. Chem. Soc . 2010 , 132 , 596. Park, Y.-C.; Tokiwa, H.; Kakinuma, K.; Watanabe, M.; Uchida, M., J. Power Sources 2016 , 315 , 179. Badam, R.; Vedarajan, R.; Matsumi, N., Chem. Commun . 2015 , 51 , 9841. Lopez-Haro, M.; Guétaz, L.; Printemps, T.; Morin, A.; Escribano, S.; Jouneau, P. H.; Bayle-Guillemaud, P.; Chandezon, F.; Gebel, G., Nat. Commun . 2014 , 5 , 5229. Fujigaya, T.; Hirata, S.; Berber, M. R.; Nakashima, N., ACS Appl. Mater. Interfaces 2016 , 8 , 14494. Jayawickrama, S. M; Han, Z. et al ., in review.
Kristopher Ray Simbulan Pamintuan, Angelika Michelle C. Katipunan, Patricia Ann O. Palaganas et al.
International Journal of Renewable Energy Development · 2020
Plant-Microbial Fuel Cell (PMFC) technology is a promising bioelectrochemical system that can exploit natural plant rhizodeposition to generate electricity. PMFCs can be used to simultaneously generate electricity while growing edible plants, as illustrated in this study. However, the common problem encountered for soil PMFCs is the low power output. To solve this problem, the stacking behavior of PMFCs was examined to maximize the power output of several cells. A grid of 9 PMFCs (3x3) was constructed with stainless steel and carbon fiber electrodes growing green beans (V. ungiculata spp. sesquipedalis) for stacking purposes. Stacking results have shown that too many cells connected in series will result in voltage losses, while stacking in parallel conserves voltage between cells. Stacking a maximum of 3 cells in series is acceptable based on the results, since cumulative stacking revealed that voltage reversals can reduce the overall potential of the stack if there are too many connected cells. Stack combinations were also tested, resulting in an enhanced performance upon combining series and parallel connections allowing power to be amplified and power density to be conserved. The combination of three sets of three cells in series stacked in parallel (3S-P) generated the highest power and power density (160.86 μW/m2) amongst all combinations, showing that power amplification without losses to power density are possible in PMFC stacking. Overall, proper stacking combinations have been shown to greatly affect the performance of PMFCs. It is hoped that the results of this study will contribute to the efforts of applying PMFC technology on a larger scale.
Minling Shao, Muhammad Nadeem Zafar, Magnus Falk et al.
ChemPhysChem · 2013
Abstract After initial testing and optimization of anode biocatalysts, a membraneless glucose/oxygen enzymatic biofuel cell possessing high coulombic efficiency and power output was fabricated and characterized. Two sugar oxidizing enzymes, namely, pyranose dehydrogenase from Agaricus meleagris ( Am PDH) and flavodehydrogenase domains of various cellobiose dehydrogenases (DH CDH ) were tested during the pre‐screening. The enzymes were mixed, “wired” and entrapped in a low‐potential Os‐complex‐modified redox‐polymer hydrogel immobilized on graphite. This anode was used in combination with a cathode based on bilirubin oxidase from Myrothecium verrucaria adsorbed on graphite. Optimization showed that the current density for the mixed enzyme electrode could be further improved by using a genetically engineered variant of the non‐glycosylated flavodehydrogenase domain of cellobiose dehydrogenase from Corynascus thermophilus expressed in E. coli (ngDH Ct CDHC310Y ) with a high glucose‐turnover rate in combination with an Os‐complex‐modified redox polymer with a high concentration of Os complexes as well as a low‐density graphite electrode. The optimized biofuel cell with the Am PDH/ngDH Ct CDHC310Y anode showed not only a similar maximum voltage as with the biofuel cell based only on the ngDH Ct CDHC310Y anode (0.55 V) but also a substantially improved maximum power output (20 μW cm −2 ) at 300 mV cell voltage in air‐saturated physiological buffer. Most importantly, the estimated half‐life of the mixed biofuel cell can reach up to 12 h, which is apparently longer than that of a biofuel cell in which the bioanode is based on only one single enzyme.
Stephane Chevalier, Jean-Christophe Olivier, Christophe Josset et al.
ECS Meeting Abstracts · 2018
Polymer Electrolyte Membrane (PEM) fuel cells are considered as promising clean sources for automotive applications. A key challenge to reduce the cost of this technology is to increase the power density by operating PEM fuel cells at high current densities. Part of the research are focused in developing and designing new materials for this technology such as advanced catalyst layers (CL), new gas diffusion layers (GDL) structure, or innovative cell assembly conditions (clamping pressure, channel design…)[1]. To assess the performance of new materials, in situ characterisation techniques are required. Electrochemical impedance spectroscopy (EIS) is one of the most used technique to characterise the material impact onto the fuel cell mass/charge transfer, ohmic resistance and mass transport. However, due to the large number of parameters which has to be identified, inaccuracy in the identification process may arise leading to incorrect fuel cell material properties characterisation [2]. In authors’ recent work [3], it was shown that current density distributions can be used as a useful information to characterise fuel cell material properties. Thus, in this communication we will present a segmented cell designed and built to measure current density distribution along the channel while allowing optical access inside the channel to visualise the presence of liquid water. A range of fuel cell GDLs is characterised in situ in this cell for a range of operating conditions. The effective diffusivity of the GDLs is directly obtained from the current density distribution without any knowledge of the other fuel cell parameter (membrane ohmic resistance or CL kinetics). The values of effective diffusivity obtained using our methodology are compared to the ones obtained through EIS measurements, and their respective accuracy will be discussed. In addition, examples on the use of this characterisation cell to assess the performance of channel designs and fuel cell assembly conditions will be given. The results presented in this communication will introduce a novel fuel cell characterisation methodology which can strongly improve the development of more efficient fuel cell systems. References [1] T. Yoshida, K. Kojima, Toyota MIRAI Fuel Cell Vehicle and Progress Toward a Future Hydrogen Society , Interface Mag. 24 (2015) 45–49. [2] S. Chevalier, D. Trichet, B. Auvity, J.C. Olivier, C. Josset, M. Machmoum, Multiphysics DC and AC models of a PEMFC for the detection of degraded cell parameters , Int. J. Hydrogen Energy. 38 (2013) 11609–11618. [3] S. Chevalier, C. Josset, B. Auvity, Analytical solutions and dimensional analysis of pseudo 2D current density distribution model in PEM fuel cells , Renew. Energy. 125 (2018) 738–746.
Rebecca Isseroff, Benjamin Akhavan, Cheng Pan et al.
MRS Proceedings · 2013
ABSTRACT Obstructing commercialization of Proton Exchange Membrane Fuel Cells (PEMFC) is the soaring cost of platinum and other catalysts used to increase membrane efficiency. The goal of this investigation is to find a relatively inexpensive catalyst for coating the membrane and enhancing the efficiency of the PEMFC. Graphene oxide was reduced using NaBH 4 in the presence of metal salts, primarily KAuCl 4 and K 2 PtCl 4 , to synthesize metal-nanoparticle/reduced graphene oxide (RGO). FTIR indicated the successful synthesis of RGO, while Transmission Electron Microscopy displayed the presence of nanoparticles on RGO sheets. Nafion® membranes were coated with metal-nanoparticle/RGO and tested in an experimental PEMFC alongside bare Nafion®, Gold (Au) nanoparticles, and RGO. The metal-nanoparticle/RGO composites enhanced the PEMFC compared to bare Nafion®. Au-RGO, the best catalyst composite, increased the efficiency up to 150% better than nanoparticles or RGO alone while using only 1% of the concentration of Au nanoparticles. Theoretical power output of the Au-RGO synergy could increase fuel cell efficiency up to 18 times more than the Au-nanoparticles themselves by altering concentrations of Au nanoparticles in Au-RGO. The Au nanoparticles changed the structure and catalytic ability of graphene in the Au-RGO, offering a promising future for PEM fuel cell technology.
Mónica Mejía‐López, Laura Verea, Pathiyammattom Joseph Sebastian et al.
Fuel Cells · 2021
Abstract An experimental design was performed to study the combined effects of the parameters used for bacteria selective biofilm formation. The parameters were the potential applied, the time of the biofilm formation with electroactive bacteria or the biofilm formation, and the initial substrate concentration in the medium. The performance of the biofilms formed was compared by their kinetic parameter the apparent electron transfer rate constant ( K app ), which was obtained from cyclic voltammetry analysis. The results from the experimental design showed that the highest K app of 0.56 s −1 was with the potential applied of −0.45 V for 5 h and 12 mM of the initial substrate concentration in the medium. New values of these parameters were calculated from the statistical analysis of the experimental design results and successfully higher value of K app of 0.64 s −1 can be calculated and obtained. The electroactivity and capability of the biofilm for hydrogen production was also proved in a single chamber microbial electrolysis cell, and a hydrogen production yield of 0.24 m 3 H 2 /m 3 d was obtained. The biofilm formed with these last parameters was also identified with molecular techniques as Exiguobacterium which has barely been reported as electroactive bacteria and used for hydrogen production.
Mohamed Derbeli, Oscar Barambones, Jose Antonio Ramos-Hernanz et al.
Energies · 2019
Proton exchange membrane fuel cell (PEMFC) topology is becoming one of the most reliable and promising alternative resource of energy for a wide range of applications. However, efficiency improvement and lifespan extension are needed to overcome the limited market of fuel cell technologies. In this paper, an efficient approach based on a super-twising algorithm (STA) is proposed for the PEMFC system. The control objective is to lengthen the fuel cell lifetime by improving its power quality, as well as to keep the system operating at an optimal and efficient power point. The algorithm adjusts the PEMFC operating point to the optimum power by tuning the duty cycle of the boost converter. The closed-loop system includes the Heliocentris hy-ExpertTM PEMFC, DC–DC boost converter, DSPACE DS1104, dedicated PC, and a programmable electronic load. The practical implementation of the proposed STA on a hardware setup is performed using a dSPACE real-time digital control platform. The data acquisition and the control system are conducted together with the dSPACE 1104 controller board. To demonstrate the performance of the proposed algorithm, experimental results are compared with 1-order sliding mode control (SMC) under different load resistance. The obtained results demonstrate the validity of the proposed control scheme by ensuring at least 72% of the maximum power produced by PEMFC. In addition, it is proven that the STA ensures all the fundamental properties of the 1-order SMC, as well as providing chattering reduction of 91%, which will ameliorate as a consequence the fuel cell lifetime.
Edi Leksono, Justin Pradipta, Tua Agustinus Tamba
Journal of Mechatronics, Electrical Power, and Vehicular Technology · 2012
One essential parameter in fuel cell operation is oxygen excess ratio which describes comparison between reacted and supplied oxygen number in cathode. Oxygen excess ratio relates to fuel cell safety and lifetime. This paper explains development of air feed model and oxygen excess ratio calculation in commercial self-humidified PEM fuel cell system with 1 kW output power. This modelling was developed from measured data which was limited in open loop system. It was carried out to get relationship between oxygen excess ratio with stack output current and fan motor voltage. It generated fourth-order 56.26% best fit ARX linear polynomial model estimation (loss function = 0.0159, FPE = 0.0159) and second-order ARX nonlinear model estimation with 75 units of wavenet estimator with 84.95% best fit (loss function = 0.0139). The second-order ARX model linearization yielded 78.18% best fit (loss function = 0.0009, FPE = 0.0009).
Hsiu Lu Chiang, Teng Lang Feng, Ay Su et al.
Advanced Materials Research · 2014
Hydrogen is known to be an ideal fuel that provides zero-emission energy. Fuel cells have emerged as one of the most promising candidates for fuel-efficient and emission-free vehicle power generation. PEMFC stacks require liquid cooling which can be operated in an open-cathode mode with air supplied by one or several fans, thus reducing the overall complexity of the PEMFC system. In this study, an open cathode PEMFC is used as the dependable power source and experiments are carried out to investigate the temperature characteristic of open cathode PEMFC. Combined with the using of oxidant and cell stack cooling, the optimal air fan supply voltage is 9.0V, and the maximal power can be obtained is 355W.
Dong Tang, Hui Min Lv, Chang Yuan Li
Advanced Materials Research · 2012
A new tubular cathode support for Direct Ethanol Fuel Cell (DEFC) was prepared by the gelcasting process using mesocarbon microbead(MCMB) and graphite as the main raw materials. Through the tubular cathode electrical property test, the advantages and disadvantages of cathode tube performance are studied at different graphite proportion. The results showed that when the graphite is more than 30 percent, the charge transmission ability has become extremely close. When the graphite ratio is 40 and 50 percent, the electrical performance is the best. With the graphite doping ratio of 40 percent, the electrode electrochemical reaction will have been reinforced when the temperature is high. When the air flow is 100 ml/min, the electricity capacity is better.
Srinivasa Reddy Badduri, G. Naga Srinivasulu, S. Srinivasa Rao
Materials Science Forum · 2019
A 3-D computational model was developed to examine the proton exchange membrane fuel cell (PEMFC) performance using Bio inspired (Bio channel) flow channel design bipolar plate. The model was developed using ANSYS FLUENT-15.0 software and simulations were carried out at 100 % humidity conditions. The parameters such as pressure distribution, hydrogen and oxygen concentrations and proton conductivity were briefly presented. The simulation results of bio channel are presented in the form of polarization curves. The results of a Bio channel compare with the conventional flow channel and observed that the bio channel gives a less pressure drop, uniform distribution of reactants and high cell voltage at a particular current density. From the observation from the polarization data, the bio channel performance was 20% higher than triple serpentine flow channel.
Karishma Maheshwari, Monika Sogani, Kumar Sonu et al.
ChemistrySelect · 2025
Abstract The current study employs the microbial desalination cell (MDC) and uses cost‐effective bio‐based polymeric membranes. The membrane was developed using the flowering plant Delonix regia flower pod powder (DRF), which was then mixed with polyurethane (PU) (Control MDC). The addition of filler material, glass powder derived from waste (DRFG), to the DRF: PU (50:50 v/v) mixture in a ratio of 1:1 (Test MDC) was done due to the presence of silicates in the elemental composition of glass powder, which will lead to improved hydration, power densities, and ion exchange capabilities. The study revealed that the DRF and DRFG membranes had an ion exchange capacity of 0.078 and 0.098 mmol H + /g, respectively. The analysis revealed that adding recycled glass powder increased the ion exchange capability by 1.25 times as compared to the control MDC. The membranes developed for the MDC system were used to treat the RO‐reject water collected from a household RO system in Varanasi, India. The results showed that the power densities of control and test MDC systems were 55 and 230 mW/m 2 , respectively. Additionally, after 30 days of operation, the ion exchange capacity recorded was 0.040 and 0.095 mmol H + /g for control and test MDC systems, respectively.
Deborah J Myers
ECS Meeting Abstracts · 2018
Over the past decade, the intrinsic oxygen reduction reaction (ORR) activity of platinum-based nanoparticle catalysts for polymer electrolyte fuel cells (PEFCs) has been improved by over an order of magnitude, with numerous catalysts now exceeding the catalytic activity target (>0.44 A/mg-Pt) established for the automotive propulsion power application. 1-3 However, the majority of catalysts meeting the activity targets are unable to achieve the current densities at low catalyst loadings (cathode loading: 0.1 mg-Pt/cm²) necessary to meet the automotive performance and cost targets simultaneously. 2 Many of the high activity catalysts also rapidly lose activity during voltage cycling in the PEFC environment. 2,4 Research focus in recent years has broadened beyond catalyst activity improvement to the understanding the sources and mechanisms of activity and performance loss and using that knowledge to mitigate the losses. For example, the major source of electrochemically-active surface area (ECA) loss for platinum nanoparticles is dissolution of particles of <~4 nm, leading to the development of catalysts with larger as-prepared mean diameters . 5,6 It has also been determined that base metal is rapidly lost from platinum-base alloy nanoparticles during electrode preparation and during voltage cycling in the fuel cell environment, leading to development of catalysts with lower initial base metal content and “pre-leaching” of base metal. 4 In state-of-the-art catalysts, the platinum or platinum alloy nanoparticles are supported on high-surface-area carbon powders, such as Vulcan XC72R, Ketjen black, or graphitized carbon blacks. These inexpensive supports fulfill the necessary functions of electron conduction and dispersing and anchoring the catalyst particles. However, they are prone to oxidation and have weak interaction with the Pt nanoparticles. These shortcomings allow the nanoparticles to migrate and coalesce during fuel cell operation and to become disconnected from the support due to oxidation, leading to ECA loss, with support oxidation also causing loss of catalyst layer porosity. 7 There have been extensive alternative support development efforts aimed at addressing these issues while maintaining the electrical conductivity of carbon (~2 S/cm). 8 A wide array of alternative supports have been developed, including doped oxides, carbides, 9,10 and nitrides, to name a few, but most lack the requisite high surface area and/or high electrical conductivity. 8 While a improved materials are the ultimate solution to the carbon support instability issues, automotive fuel cell system developers have designed system-level mitigation strategies to allow the existing carbon supports to achieve the lifetime targets. A more recently-studied support issue is the impact of support structure on catalyst utilization. 11 While the higher surface area carbon supports are desirable in terms of their ability to disperse the catalyst nanoparticles, they contain internal porosity. A significant portion of the catalyst nanoparticles can be buried in the pores. 12 Limited proton conductivity in the pores leads to under-utilization of the buried catalyst particles at high current densities and, especially, under low humidity conditions. 11 To overcome this limitation, recent efforts focus on catalyst deposition methods or carbon supports that can limit catalyst deposition to the external surface of the support. 11,13 This presentation will give an overview of the current understanding of catalyst and catalyst support performance and performance stability and the interactions between catalyst, support, and ionomer that define these properties. The impact of catalyst and support degradation on the ionomer properties will also be discussed. Acknowledgements This work was supported by the U.S. Department of Energy (DOE), Energy Efficiency and Renewable Energy, Fuel Cell Technologies Office under the auspices of the Fuel Cell Performance and Durability (FC-PAD) Consortium. Argonne National Laboratory is managed for the U.S. DOE by the University of Chicago Argonne, LLC, under contract DE-AC-02-06CH11357. References U.S. DOE FCTO Multi-Year Research, Development, and Demonstration Plan, 2016. A. Kongkanand et al., J. Phys. Chem. Lett. , 7 (2016) 1127−1137. M. Debe , Nature , 486 (2012) 43–51. R. Mukundan, et al., 232 nd Electrochemical Society Meeting, National Harbor, MD, Oct., 2017, Abstract 1681. J.A. Gilbert, et al., Electrochimica Acta , 173 (2015) 223-234. K. Yu, et al., Chemistry of Materials , 2014. L. Castanheira, et al., ACS Catal. 5 (2015) 2184–2194. Y. Shao, et al., J. Mater. Chem. 19 (2009) 46–59. M. Nie, et al., J. Power Sources , 162 (2006) 173-176. H. Chhina, et al, J. Power Sources , 179 (2008) 50-59. K. Shinozaki, et al., J. Electrochem. Soc. , 158 (2011) B467-B475. K.L. More, “FC136 – FC-PAD: Components and Characterization”, 2017 DOE-FCTO Annual Merit Review and Peer Evaluation, June 6, 2017. https://www.hydrogen.energy.gov/pdfs/review17/fc136_more_2017_o.pdf A. Kongkanand, “FC144 – Highly-Accessible Catalysts for Durable High-Power Performance”, 2017 DOE-FCTO Annual Merit Review and Peer Evaluation, June 7, 2017. https://www.hydrogen.energy.gov/pdfs/review17/fc144_kongkanand_2017_o.pdf
M. L. Jiménez González, Carlos Hernández Benítez, Zabdiel Abisai Juarez et al.
Catalysts · 2020
In this paper, the effect of cathode configuration on the performance of a membrane-less microbial fuel cell (MFC) was evaluated using three different arrangements: an activated carbon bed exposed to air (MFCE), a wetland immersed in an activated carbon bed (MFCW) and a cathode connected to an aeration tower featuring a water recirculation device (MFCT). To evaluate the MFC performance, the efficiency of the organic matter removal, the generated voltage, the power density and the internal resistance of the systems were properly assessed. The experimental results showed that while the COD removal efficiency was in all cases over 60% (after 40 days), the MFCT arrangement showed the best performance since the average removal value was 82%, compared to close to 70% for MFCE and MFCW. Statistical analysis of the COD removal efficiency confirmed that the performance of MCFT is substantially better than that of MFCE and MFCW. In regard to the other parameters surveyed, no significant influence of the different cathode arrangements explored could be found.
Sheng-Hu Zhen, Yang-Yang Yu, Rong-Rong Xie et al.
Fermentation · 2023
Chitin is one of the most abundant polymers in nature, with chitinous biomass often discarded as food waste and marine debris. To explore an effective way to degrade chitin, in this work, anaerobic sludge was inoculated at the anode of a two-chamber microbial fuel cell (MFC), and chitin was degraded via anaerobic respiration and fermentation. The results showed that the anaerobic sludge could degrade chitin under both the anaerobic respiration and fermentation modes, with similar degradation rates (7.10 ± 0.96 and 6.96 ± 0.23 C-mg/L·d−1). The open-circuit voltage and output current density could roughly reflect the degradation of chitin in the MFC. The maximum current density generated through the anaerobic sludge degradation of chitin via anaerobic respiration was 160 mA/m2, and the maximum power density was 26.29 mW/m2. The microbial sequencing results revealed substantially different microbial community profiles, with electroactive bacteria (EAB) flora and fermentative bacteria (Longilinea) as the main microbial groups that degraded chitin via anaerobic respiration and fermentation, respectively. Therefore, anaerobic sludge may be a good choice for the treatment of refractory biomass due to its abundant electroactive and fermentative flora.
Ahmed H.Shallal, Ibtehal Kareem Shakir
Iraqi Journal of Chemical and Petroleum Engineering · 2022
Zinc-air fuel cells (ZAFCs) are a promising energy source that could compete with lithium-ion batteries and perhaps proton-exchange membrane fuel cells (PEMFCs) for next-generation electrified transportation and energy storage applications. In the present work, a flow-type ZAFC with mechanical rechargeable was adopted, combined with an auxiliary cell (electrolyzer) for zinc renewal and electrolyte recharge to the main cell. In this work a practical study was performed to calculate the cell capacity (Ah), as well as study the electrolysis cell efficiency by current efficiency, and study the effective parameters that have an influence on cell performance such as space velocity and current density. The best parameters were selected to obtain the best performance for cell operation. The obtained cell capacity was 2.4Ah. The best performance of the electrolyzer was obtained with 0.6min-1 space velocity. At the same time, the best performance of the electrolyzer was when the value of the current density was 200A/m2
Yoshiyuki Matsuda, Takahiro Shimizu, Daichi Imamura
ECS Meeting Abstracts · 2024
Introduction The allowable concentration of formic acid is defined as 0.2 ppm in Grade D of ISO 14687: 2019, which is the hydrogen quality specification for fuel cell vehicles. The effect of formic acid in hydrogen on polymer electrolyte fuel cell (PEFC) performance has been reported by some researchers [1-4], but the reaction mechanism of formic acid in the PEFC is not well understood. In this study, the reaction behavior of formic acid in the PEFC and its impact on voltage decrease were investigated. Experimental The effect of formic acid in hydrogen was evaluated using a single cell. A “JARI Cell 2” with a 25 cm 2 electrode area and double serpentine flow channels was used in the experiment. The anode and cathode catalysts were Pt/C (TEC10E50E, Tanaka Kikinzoku Kogyo). The platinum loadings on the anode and cathode were 0.05 mg cm -2 and 0.30 mg cm -2 , respectively. The electrolyte membrane was a fluorine-based material with a thickness of 12 μm. The 22BB (SGL Carbon) gas diffusion layers were used on both the anode and cathode. The single-cell tests were performed at a cell temperature of 60°C and without external humidification. This is because formic acid easily dissolves in water and is likely to be exhausted from the cell with water at high humidification, so no humidification is considered the most severe condition. Before formic acid addition, the preconditioning was conducted at 1.0 A cm -2 of current density using high-purity hydrogen as a fuel for more than 10 hours. Then, formic acid (15-300 ppm) was started to supply the anode. After a period of time, the supply of formic acid to the anode was stopped and the voltage recovery was evaluated. Results and discussion Figure 1 shows the voltage drop over time due to formic acid in hydrogen at a current density of 1.0 A cm -2 and cell temperature of 60˚C. The voltage dropped quickly after the start of the formic acid supply, but the amount was small even at high formic acid concentrations. The voltage drop due to formic acid was 14 mV after 25 hours at 60 ppm and 20 mV after 5 hours at 300 ppm. The voltage was recovered after stopping the formic acid addition. To understand the reaction behavior of formic acid during the fuel cell operation, the anode and cathode exhaust gas were analyzed by gas chromatograph-mass spectrometer. The result showed that no formic acid was detected from the anode or cathode while the fuel cell was operated at a current density of 1.0 A cm -2 with 15 ppm formic acid addition to the anode. Meanwhile, the amount of CO 2 equivalent to that supplied to the anode as formic acid was detected from the cathode exhaust gas. The results suggest that formic acid supplied to the anode permeated through the electrolyte membrane as shown in Fig. 2 and was oxidized at the cathode. Acknowledgment This work is based on results obtained from a project, JPNP18011, commissioned by the New Energy and Industrial Technology Development Organization (NEDO). References [1] Shogo Watanabe, Masahito Tatsumi, Motoaki Akai, .2004 Fuel Cell Seminar Abstracts, 248-251 (2004). [2] Jaana Viitakangas, Jari Ihonen, Pauli Koski, Matti Reinikainen, Thor Anders Aarhaug, J. Electrochem. Soc., 165 , F718 (2018). [3] Xiaoyu Zhang, Hugo M. Galindo, Hector F. Garces, Philip Baker, Xiaofeng Wang, Ugur Pasaogullari, Steven L. Suib, Trent Molter, J. Electrochem. Soc., 157 , B409-B414 (2010) [4] Takahiro Shimizu and Yoshiyuki Matsuda., JARI Research Journal, 20190201 (2019). Figure 1