共查询到20条相似文献，搜索用时 15 毫秒
1.
V. Krikstolaityte P. Lamberg M. D. Toscano M. Silow O. Eicher‐Lorka A. Ramanavicius G. Niaura L. Abariute T. Ruzgas S. Shleev 《Fuel Cells》2014,14(6):792-800
Direct electron transfer (DET) between cellobiose dehydrogenase from Humicola insolens ascomycete (HiCDH) and gold nanoparticles (AuNPs) was achieved by modifying AuNPs with a novel, positively charged thiol N‐(6‐mercapto)hexylpyridinium (MHP). The DET enabled the use of the HiCDH enzyme as an anodic biocatalyst in the design of a mediatorless carbohydrate/oxygen enzymatic fuel cell (EFC). A biocathode of the EFC was based on bilirubin oxidase from Myrothecium verrucaria (MvBOx) directly immobilised on the surface of AuNPs. The following parameters of the EFC based on Au/AuNP/MHP/HiCDH bioanode and Au/AuNP/MvBOx biocathode were obtained in quiescent air saturated PBS, pH 7.4, containing: (i) 5 mM glucose‐open‐circuit voltage (OCV) of 0.65 ± 0.011 V and the maximal power density of 4.77 ± 1.34 μW cm−2 at operating voltage of 0.50 V; or (ii) 10 mM lactose‐OCV of 0.67 ± 0.006 V and the maximal power density of 8.64 ± 1.91 μW cm−2 at operating voltage of 0.50 V. The half‐life operation times of the EFC were estimated to be at least 13 and 44 h in air saturated PBS containing 5 mM glucose and 10 mM lactose, respectively. Among advantages of HiCDH/MvBOx FCs are (i) simplified construction, (ii) relatively high power output with glucose as biofuel, and (iii) the absence of the inhibition of the HiCDH based bioanode by lactose, when compared with the best previously reported CDH based bioanode. 相似文献
2.
M. A. Abdelkareem E. T. Kasem N. Nakagawa E. A. M. Abdelghani A. A. Elzatahry K. A. Khalil N. A. M. Barakat 《Fuel Cells》2014,14(4):607-613
Mass transfer is a key parameter affecting the performance of the passive direct methanol fuel cells (DMFCs), which work under natural convection. In this study, effect of carbon nanofibers (CNFs) addition to the cathode microporous layer (MPL) on the performance of the passive DMFCs was investigated. The results indicated that CNFs content has a significant influence on both of the mass transport and the electrochemical surface area (ECSA). Interestingly, addition of the CNFs (20 wt.%) leads to increase the power density of the passive DMFC to 160% compared to pristine carbon black MPL. At low current density, the CNFs content has no influence on the performance, while at high current density the maximum performance can be obtained at 20 wt.% CNFs then the performance decreases with further increase in the CNFs content. Although the highest catalyst utilization is observed at 40 wt.% CNFs, a maximum power density of 36 mW cm–2 can be obtained at 20 wt.% CNFs and this is related to the significant effect of the mass transfer resistance under the passive operation conditions. Overall, addition of CNFs to the MPL can be considered an effective strategy to modify the passive DMFCs performance. 相似文献
3.
Our study explores the use of porous carbon as anode catalyst support to improve borohydride utilization in a direct borohydride fuel cell. Pt catalysts supported by carbon aerogel (CA) and macroporous carbon (MPC) are synthesized by template method. The pores in porous carbon materials catch hydrogen bubbles to regulate the contact of anolyte with catalytic sites, and this leads to the depression of hydrogen evolution during BH4− electrooxidation. However, the hydrogen bubbles in the pores simultaneously deteriorate charge carrier transport and thus increase anode polarization. The CA‐supported Pt catalyst improves the coulombic efficiency of BH4− electrooxidation. However, the MPC‐supported Pt catalyst performed better than the CA‐supported Pt catalyst. MPC also has a good pore distribution, which improves the coulombic efficiency of BH4− electrooxidation without decreasing anode performance. 相似文献
4.
Bioelectrocatalytic reduction of O2 into water was archived at diffusion‐controlled rate by using enzymes (laccase from Trametes sp. and bilirubin oxidase from Myrothecium verrucaria, which belong to the family of multi‐copper oxidase) adsorbed on mesoporous carbon aerogel particle without a mediator. The current density was predominantly controlled by the diffusion of dissolved O2 in rotating‐disk electrode experiments, and reached a value as large as 10 mA cm–2 at 1 atm O2, 25 °C, and 8,000 rpm on the laccase‐adsorbed electrode. The overpotential of the bioelectrocatalytic reduction of O2 was 0.4–0.55 V smaller than that observed on a Pt disk electrode. Without any optimization, the laccase‐adsorbed biocathode showed stable current intensity of the O2 reduction in an air‐saturated buffer at least for 10 days under continuous flow system. 相似文献
5.
《Fuel Cells》2018,18(2):219-226
Cellulose, which accounts for more than half of the carbon content in plants, has become a popular feedstock for biofuel production. In this work, direct electricity generation from dissolved cellulosic biomass in an alkaline fuel cell is explored without energy‐intensive process. The effect of different cellulose dissolution solvents on the electricity production is investigated. Results show dissolution treatment can remarkably affect the fuel cell performance. When NaOH/urea/thiourea is chosen as a solvent, the specific capacity of cellulose is about sixfold higher than that using only NaOH as solvent. The limiting current density and the maximum power density reach 0.85 mA cm−2 and 0.07 mW cm−2, respectively. This power density surpasses those of any existing biotic or abiotic designs. Electrochemical characterizations demonstrate that the remarkable activity improvement towards the cellulose oxidation reaction in NaOH/urea/thiourea aqueous solution is due to the lower charger transfer resistance and higher energy transfer efficiency. 相似文献
6.
直接甲醇燃料电池质子交换膜的发展现状 总被引：1，自引：0，他引：1
直接甲醇燃料电池(DMFC)是20世纪90年代兴起的第六代燃料电池,以其诸多的优点引起人们的广泛关注和研究。其中聚合物电解质膜是DMFC的关键技术,起着隔离阴阳极、质子传输、绝缘电子的作用。它的作用决定着DMFC的输出功率、电池效率、成本及应用前景。本文介绍了已商品化的全氟磺酸膜(Nafion膜)的结构及性能、以及替代膜的国内外发展现状,指出DMFC用膜的研究是21世纪能源研究的重点。 相似文献
7.
The direct formate fuel cell (DFFC) has recently been demonstrated as a viable alkaline direct liquid fuel cell (DLFC) that does not require addition of hydroxide to the fuel stream for operation. In this work, we report that the DFFC can produce significant power at low temperatures without added hydroxide, especially when compared with other alkaline DLFCs powered by alcohols. Using oxygen at the cathode, the DFFC powered by 1 M HCOOK achieves a maximum power density of 106 mW cm–2 at 50 °C and 64 mW cm–2 at 23 °C. Using air at the cathode, the same DFFC achieves a maximum power density of 76 mW cm–2 at 50 °C and 27 mW cm–2 at 23 °C. These power densities were achieved without addition of hydroxide to the fuel stream. Constant current operation demonstrates that the maximum power density can be maintained at least for several hours of operation. Finally, we use electrochemical analysis to demonstrate that the formate oxidation reaction is not dependent on pH between 9 and 14, which permits the use of formate fuel without added hydroxide in the DFFC. An alkaline DLFC that does not require added hydroxide is promising for safe and practical operation. 相似文献
8.
Ni foam has been used as a substrate for the anode electrocatalyst in our previous works. In this study, the effect of nickel foam as an anode electrode in direct borohydride cells has been investigated under steady state/steady‐flow and uniform state/uniform‐flow systems, since nickel has catalytic property. Cathode catalyst used has been 0.3 mg cm–2 on PTFE‐treated Toray carbon paper. The results have showed that power densities have increased by increasing the temperature. Peak power densities of 5.01 and 9.55 mW cm–2 have been achieved at 25 and 60 °C, respectively, for 1.5 mol dm–3 NaBH4. On the other hand, the electrochemical performance has not been significantly different by the sodium borohydride concentration; only a small increase of power density has been observed in steady state/steady‐flow system, and only a small decrease of fuel utilization ratio has been obtained in uniform state/uniform‐flow systems. 相似文献
9.
A. Fraiwan S. P. Adusumilli D. Han A. J. Steckl D. F. Call C. R. Westgate S. Choi 《Fuel Cells》2014,14(6):801-809
Microbial fuel cells (MFCs) are an alternative electricity generating technology and efficient method for removing organic material from wastewater. Their low power densities, however, hinder practical applications. A primary limitation in these systems is the anode. The chemical makeup and surface area of the anode influences bacterial respiration rates and in turn, electricity generation. Some of the highest power densities have been reported using large surface area anodes, but due to variable chemical/physical factors (e.g., solution chemistry, architecture) among these studies, meaningful comparisons are difficult to make. In this work, we compare under identical conditions six micro/nano‐structured anodes in micro‐sized MFCs (47 μL). The six materials investigated include carbon nanotube (CNT), carbon nanofiber (CNF), gold/poly (ϵ‐caprolactone) microfiber (GPM), gold/poly(ϵ‐caprolactone) nanofiber (GPN), planar gold (PG), and conventional carbon paper (CP). The MFCs using three dimensional anode structures (CNT, CNF, GPM, and GPN) exhibited lower internal resistances than the macroscopic CP and two‐dimensional PG anodes. However, those novel anode materials suffered from major issues such as high activation loss and instability for long‐term operation, causing an enduring problem in creating widespread commercial MFC applications. The reported work provides an in‐depth understanding of the interplay between micro‐/nano‐structured anodes and active microbial biofilm, suggesting future directions of those novel anode materials for MFC technologies. 相似文献
10.
The development of low cost alkaline anion solid exchange membranes requires high ionic conductivity, low liquid uptake, strong mechanical properties and chemical stability. PVA/PSSA blends cross‐linked with glutaraldehyde and decorated with titanium dioxide nanoparticles introduce advantages relative to the pristine membrane of PVA and PVA/PVP membranes due to their improved electrical response and low methanol uptake/ swelling ratio allowing their use in alkaline direct methanol fuel cells. 相似文献
11.
Improving the performance of anode is a crucial step for increasing power output of marine sediment microbial fuel cells (SMFCs). A multi‐walled carbon nanotube/polyaniline (MWCNTs/PANI) modified anode was prepared by the way of electrochemical deposition and its electrochemical performance is investigated in this paper. Result shows that the wettability of carbon felt becomes better and the number of bacteria (9.52 × 1012 m−2) on anode biofilm is increased respectively, which is 9 times higher than that of the unmodified. The anti‐polarization ability of the modified anode increases significantly and its kinetic activity of electron transfer increases 4 times. Its exchange current density is 3.62 × 10−5 A cm−2. The maximum power density of the modified SMFC reaches 527.0 mW m−2, which is 4 times higher than that of the unmodified one. Finally, a novel molecular synergistic mechanisms for the enhanced SMFC is also presented, based on the higher bacteria number, the capacitive performance of PANI, the hydrogen bond interaction and higher conductivity of MWCNTs. This excellent electrochemical performance makes the MWCNTs/PANI composite be a potential choice for higher output SMFC. 相似文献
12.
The direct borohydride fuel cell (DBFC) has attracted increasing interest as a potential high power source for mobile and portable applications. Engineering design plays an important role in the development of the DBFC. This paper reports data for the selection of anode, cathode, and membrane materials for the DBFC. The best DBFC performance is achieved with a Au anode, a Pt cathode, and a 3541P ion exchange membrane. The use of non‐precious catalysts, e.g., Ag, leads to promising results. 相似文献
13.
T. Z. Fu J. Liu Z. M. Cui J. Ni G. Zhang H. B. Yu C. J. Zhao Y. H. Shi H. Na W. Xing 《Fuel Cells》2009,9(5):570-578
The sulphonated phenol novolac (PNBS) which was used as a curing agent of epoxy was synthesised from phenol novolac (PN) and 1, 4‐butane sultone and confirmed by FTIR and 1H NMR. The degree of sulphonation (DS) in PNBS was calculated by 1H NMR. The semi‐IPN membranes composed of sulphonated tetramethyl poly(ether ether ketone) (STMPEEK) (the value of ion exchange capacity is 2.01 meq g–1), epoxy (TMBP) and PNBS were successfully prepared. The semi‐IPN membranes showed high thermal properties which were measured by differential scanning calorimeter (DSC) and thermogravimetric analyses (TGA). With the introduction of the cross‐linked TMBP/PNBS, the mechanical properties, dimensional stability, methanol resistance and oxidative stability of the membranes were improved in comparison to the pristine STMPEEK membrane. Although the proton conductivities of the semi‐IPN membranes were lower than those of the pristine STMPEEK membrane, the higher selectivity defined as the ratio of the proton conductivity to methanol permeability was obtained from the STMPEEK/TMBP/PNBS‐14 semi‐IPN membrane. The results indicated that the semi‐IPN membranes could be promising candidates for usage as proton exchange membranes in direct methanol fuel cells (DMFCs). 相似文献
14.
This paper presents a simple and reliable pumpless methanol feeding (PLMF) method for application in direct methanol fuel cell (DMFC) systems. The primary feature and advantage of the PLMF is as follows: it employs an approach that allows the cathode gas pressure to be connected with a fuel container for supplying the methanol fuel into the anode fuel loop, instead of using any feeding pump or other specially designed apparatuses. The PLMF has been used in a portable 25 W DMFC system and realised feeding methanol in real time for meeting the requirements of the system. The PLMF method not only is suitable for the DMFC system, but also can be used in other liquid‐feeding fuel cell systems. 相似文献
15.
Au nanoparticles supported on Vulcan XC‐72R carbon were prepared by a modified NaBH4 method in aqueous solution and employed as electrocatalyst of oxidation for the direct borohydride fuel cell (DBFC). The morphology and structure of as‐prepared particles were examined by transmission electron microscopy (TEM) and X‐ray diffraction (XRD). It was found that Au nanoparticles were mainly about 3.0 ± 0.5 nm in size and uniformly distributed on the surface of Vulcan XC‐72R carbon. The electrooxidation behaviors of and fuel cell performances using carbon‐supported Au nanoparticles as catalysts were investigated. Compared with Au/C prepared by conventional reduction method, the kinetics of oxidation on as‐prepared carbon supported 3.0 ± 0.5 nm Au nanoparticles were significantly improved. The DBFC employing carbon supported 3.0 ± 0.5 nm Au nanoparticles showed a maximum power density of 85.3 mW cm–2 at 60 °C. 相似文献
16.
We constructed a fuel‐flexible fuel cell consisting of an alkaline anion exchange membrane, palladium anode, and platinum cathode. When an alcohol fuel was used with potassium hydroxide added to the fuel stream and oxygen was the oxidant, the following maximum power densities were achieved at 60 °C: ethanol (128 mW cm−2), 1‐propanol (101 mW cm−2), 2‐propanol (40 mW cm−2), ethylene glycol (117 mW cm−2), glycerol (78 mW cm−2), and propylene glycol (75 mW cm−2). We also observed a maximum power density of 302 mW cm−2 when potassium formate was used as the fuel under the same conditions. However, when potassium hydroxide was removed from the fuel stream, the maximum power density with ethanol decreased to 9 mW cm−2 (using oxygen as oxidant), while with formate it only decreased to 120 mW cm−2 (using air as the oxidant). Variations in the performance of each fuel are discussed. This fuel‐flexible fuel cell configuration is promising for a number of alcohol fuels. It is especially promising with potassium formate, since it does not require hydroxide added to the fuel stream for efficient operation. 相似文献
17.
Empirical model equations, proposed for polymer electrolyte fuel cells, are used to predict the cell voltage vs. current density response of a liquid feed direct methanol fuel cell. The model equations are validated against experimental data for a small-scale fuel cell over a wide range of methanol concentration and temperatures. A new empirical equation is presented which is able to predict the voltage response of liquid feed direct methanol fuel cells over a wide range of operating conditions and even in the case of very low current densities caused by, for example, the use of dilute methanol solutions or low cell temperatures. 相似文献
18.
The effect of varying operating parameters on the degradation of a single‐cell direct methanol fuel cell (DMFC) with serpentine flow channels was investigated. Fuel cell internal temperature, methanol concentration, and air and methanol flow rates were varied in experimental tests and fuel cell performance was chronologically recorded. A DMFC semi‐empirical performance model was developed to predict the polarization curves of the DMFC and validated at different operating conditions. Performance degradation was observed and modeled over time by a linear regression model. Unlike previous studies, the cumulative exposure of the operating factors to the fuel cell was considered in the degradation analysis. The degradation model shows the cell voltage generation capacity does not significantly degrade. However, the Tafel slope of the cell changes with cumulative exposure to methanol concentration and air flow, and the ohmic resistance changes with cumulative exposure to temperature, methanol and air flow. 相似文献
19.
This paper describes a dynamic fuel cell vehicle simulation tool for the battery‐hybrid direct‐hydrogen fuel cell vehicle. The emphasis is on simulation of the hybridized hydrogen fuel cell system within an existing fuel cell vehicle simulation tool. The discussion is focused on the simulation of the sub‐systems that are unique to the hybridized direct‐hydrogen vehicle, and builds on a previous paper that described a simulation tool for the load‐following direct‐hydrogen vehicle. The configuration of the general fuel cell vehicle simulation tool has been previously presented in detail, and is only briefly reviewed in the introduction to this paper. Strictly speaking, the results provided in this paper only serve as an example that is valid for the specific fuel cell vehicle design configuration analyzed. Different design choices may lead to different results, depending strongly on the parameters used and choices taken during the detailed design process required for this highly non‐linear and n‐dimensional system. The primary purpose of this paper is not to provide a dynamic simulation tool that is the “final word” for the “optimal” hybrid fuel cell vehicle design. The primary purpose is to provide an explanation of a simulation method for analyzing the energetic aspects of a hybrid fuel cell vehicle. 相似文献