PtxSny/C催化剂对DEFCs中乙醇电氧化活性的研究

In the present paper, PtxSny/C series catalysts with different atomic ration (x:y=2:1, 3:2, and 1:1) were fast synthesized with small particle size (~ 3 nm) and well dispersion by using pulse microwave assisted polyol method. The physico-chemical characteristics were determined by XRD and TEM. In order to explore PtSn’s activity towards ethanol electrooxidation, electrochemical evaluation was applied to the electrooxidation of ethanol and its main by-products including acetaldehyde and acetic acid at different temperatures. For ethanol electrooxidation, the Sn addition can improve Pt’s ability with different contributing effect depending on Sn content and temperatures. At lower temperature, Sn-poor catalysts exhibited better performance while Sn-rich catalysts gave better performance at higher temperature, which are related to surface oxygen-containing species, lattice parameters, and ohmic effect dependent on Sn content. Based on the acetaldehyde electrooxidation, Pt1Sn1/C showed the highest activity at all the temperatures; due to that Sn existence can effectively remove C2 species and inhibit the poison formation by supplying oxygen-containing species. Moreover, in the case of acetic acid electrooxidation, over PtxSny/C catalysts, there was small current produced, giving an indicator that Sn does take effect on the activation of C-C bond, and in this way help the oxidation of acetic acid to C1 species.