Acceleration of Ethanol Electro-Oxidation on a Carbon-Supported Platinum Catalyst at Intermediate Temperatures

作者：Shimada Iori^*; Oshima Yoshito; Otomo Junichiro

来源：Journal of the Electrochemical Society, 2011, 158(4): B369-B375.

DOI：10.1149/1.3545280

The performance of a direct ethanol fuel cell is expected to improve at relatively high temperatures. In this study, the electro-oxidation of ethanol on a carbon-supported platinum catalyst (Pt/C) at intermediate temperatures (235-260 degrees C) was investigated using a single cell fabricated with the CsH(2)PO(4) proton conducting solid electrolyte. The main products of ethanol electro-oxidation at intermediate temperatures were H(2), CO(2), and CH(4) while the formation of C(2) compounds was much small in comparison with the gaseous products even at a high ethanol concentration (i.e., water/ethanol molar ratio 3). An analysis of the reaction products revealed that the C-C bond dissociation ratio of ethanol is higher than 90% at intermediate temperatures. In addition, a high current efficiency for the total oxidation of ethanol (ca. 80%) was observed. The apparent activation energy for this ethanol oxidation suggests reaction paths for the formation of CO(2): the C-C bond dissociation or the subsequent oxidation of the adsorbed CH(x) species is thought to be rate-determining at intermediate temperatures. These observations clearly demonstrate the advantages of the efficient and direct use of ethanol at intermediate temperatures.

• 出版日期2011