Direct ethanol fuel cells performance

Rousseau S, Coutanceau C, Lamy C, Leger JM. 2006. Direct ethanol fuel cell (DEFC) Electrical performances and reaction products distribution under operating conditions with different platinum-based anodes. J Power Sources 158 18-24. 

Zhou WJ, Song SQ, Li WZ, Zhou ZH, Srm GQ, Xin Q, Douvartzides S, Tsiakaras P. 2005. Direct ethanol fuel cells based on PtSn anodes The effect of Sn content on the fuel cell performance. J Power Sources 140 50-58. 

Carbon-Supported Core-Shell PtSn Nanoparticles Synthesis, Characterization and Performance as Anode Catalysts for Direct Ethanol Fuel Cell... 

FIGURE 15.9. Performance comparison of RSn anode based direct ethanol fuel cells at 90°C. Anode catalysts Carbon supported PtSn with a R loading of 1.5 mg/cm, ethanol concentration 1.0 mol/L, flow rate 1.0 mL/min. Cathode (20 Pt wt.%, Johnson Matthey Inc.) with a R loading of 1.0 mg/cm, Pq2 = 2 bar. Electrolyte Naflon -115 membrane. 

Shao et al. [35] not only used a similar Ti mesh to the one presented by Scott s group but also used a Ti mesh as the cathode DL in a DMFC. The main difference between both meshes was that the one used on the cathode side was coated on both sides with carbon black (Vulcan XC-72) and PTFE (i.e., with MPLs on each side). It was shown that this novel cathode DL performed similarly to conventional CFP DLs under comparable conditions. Chetty and Scott [36] also used a catalyzed Ti mesh as the anode DL, but in a direct ethanol fuel cell (DEFC) it performed better compared to a cell with a standard DL (CFP). 

After rehearsing the working principles and presenting the different kinds of fuel cells, the proton exchange membrane fuel cell (PEMFC), which can operate from ambient temperature to 70-80 °C, and the direct ethanol fuel cell (DEFC), which has to work at higher temperatures (up to 120-150 °C) to improve its electric performance, will be particularly discussed. Finally, the solid alkaline membrane fuel cell (SAMFC) will be presented in more detail, including the electrochemical reactions involved. 

However, a number of issues, particularly those related to the performance of the electrocatalyst, should be improved in order to implement direct ethanol fuel-cell (DEFC) technology. Among them, the m or challenge is developing electrocatalysts that can break the G-C bond at relative low potentials. 

Hou H, Wang S, Jin W, Jiang Q, Sun L, Jiang L, Sun G (2011) KOH modified Nafion 112 membrane for high performance alkaline direct ethanol fuel cell. Int J Hydrogen Energ 36 5104-5109... 

Li YS, Zhao TS, Liang ZX (2009) Performance of alkaline electrolyte-membrane-based direct ethanol fuel cells. J Power Sources 187 387-392... 

Li YS, Zhao TS (2011) A high performance integrated electrode for anion-exchange membrane direct ethanol fuel cells. Int J Hydrogen Energ 36 7707-7713... 

Hou HY, Sun GQ, He RH, Wu ZM, Sun BY (2008) Alkali doped polybenzimidazole membrane for high performance alkaline direct ethanol fuel cell. J Power Sources 182(l) 95-99... 

However, poor performances and reduced Hfetimes need to be overcome for the commercialization of adapted PEFCs. Alkaline direct ethanol fuel cells are favored because they feature an increased performance and allow the use of cheaper platinum-free catalysts. 

Figure 4.38. Direct ethanol fuel cell polarization curves at 353 K. Ethanol concentration 2 M, Nation 117, O2 pressure 3 bar [183]. (Reproduced from Journal of Power Sources, 158(1), Rousseau S, Coutanceau C, Lamy C, Leger J-M, Direct ethanol fuel cell (DEFC) electrical performances and reaction products distribution under operating conditions with different platinum-based anodes, 18-24, 2006, with permission from Elsevier.)...

There is now fairly conclusive evidence that PtSn performs better than PtRu, PtPd, PtRe, and PtW in direct ethanol fuel cell experiments, especially at temperatures equal to and above 343 K [185-186, 188-192]. Furthermore, the long-term stability of PtSn (9 1 at. ratio) was promising, as the cell voltage was virtually constant around 0.45 V for 240 min at 32 mA cm and 353 K [183]. 

Rousseau, S., Coutanceau, C., Lamy, C., etal. (2006). Direct Ethanol Fuel Cell (DEFC) Electrical Performances and Reaction Products Distribution Under Operating Conditions with Different Platinum-based Anodes, J. Power Sources, 158, pp. 18-24. 

It is quite natural that all these considerations have led to enhanced interest in the uses of ethanol in fuel cells. A lot of research went into the development of direct ethanol fuel cells (DEFCs) during the last decade. Much of the research in this direction was performed in France in the group of Claude Lamy (see the review of Lamy et al., 2002). 

L. Jiang, H. Zang, G. Sun, Q. Xin, Influence of preparation method on the performance of PtSn/C anode electrocatalyst for direct ethanol fuel cells. Chin. J. Catal. 27 (2006) 15-19. 

Figure 10.14 Performances of single direct ethanol fuel cells with different PtSn/C catalysts as anode catalysts at 90 °C. Anode is PtSn/C with different Pt/Sn atomic ratio (1.33 mg Ptcm ). Solid electrolyte is...

The preliminary results showed that the caibon-supported Pt alloy acid-treated (skeletal-type) electrocatalysts are very promissing for etlmol electro-oxidation. Further work is necessary to characterize the catalysts using different surface analysis techniques and to elucidate the mechanism of ethanol electro-oxidation. Also, it is necessary to perform experiments using these electrocatalysts in gas diffusion electrodes for tests in single direct ethanol fuel cells. 

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