直接乙醇燃料电池中乙醇电氧化过程的热力学和动力学考虑

Thermodynamic and Kinetic Considerations for Ethanol Electrooxidation in Direct Ethanol Fuel Cells

从热力学和动力学角度讨论了质子交换膜燃料电池中的乙醇电氧化过程.理论计算得出直接乙醇燃料电池比乙醇重整质子交换膜燃料电池具有较高的有效能效率.从热力学分析可知,温度低于100℃时乙醇完全氧化的最大转化率仅为14%.从动力学角度考虑,PtSn/C催化剂对乙醇电氧化具有较高的催化活性,但仍不能使乙醇发生完全电氧化.热力学和动力学分析表明,操作温度是影响直接乙醇燃料电池性能的关键因素,它对开发新型催化剂和电解质膜材料提出了新的要求.

Thermodynamic and kinetic considerations for the ethanol electrooxidation in a proton exchange membrane fuel cell （PEMFC） were discussed. Theoretical calculations show that direct ethanol fuel cells （DEFCs） exhibit better exergic efficiency than ethanol reforming PEMFC. The thermodynamic analysis show that when temperature is lower than 100 ℃, the conversion of ethanol steam reforming is less than 14% for ethanol complete oxidation. The kinetic study shows that PtSn/C anodes have a relatively high activity for ethanol electrooxidation, but such activity is not high enough for ethanol complete electrooxidation. The thermodynamic and kinetic analyses suggest that the cell temperature is one of the key factors for the DEFC development.