碳载PtSn催化剂上乙醇电氧化的原位时间分辨红外光谱研究  

Ethanol Electrooxidation on Carbon Supported PtSn Catalyst: In Situ TRFTIR Study

作　　者：王琪[1] 孙公权[1] 姜鲁华[1] 朱明远[1] 汪国雄[1] 辛勤[1] 孙世刚[2] 陈青松[2] 姜艳霞[2] 陈声培[2] 

机构地区：[1]中国科学院大连化学物理研究所,辽宁大连116023 [2]固体表面物理化学国家重点实验室,厦门大学化学系,福建厦门361005

出　　处：《光谱学与光谱分析》2008年第1期47-50,共4页Spectroscopy and Spectral Analysis

基　　金：国家“863”计划项目(2003AA517040);厦门大学化学化工系国家重点实验室开放课题项目(200304)资助

摘　　要：采用调变的多元醇法制备了高分散碳载PtSn催化剂(PtSn/C),XRD测试结果表明金属粒子的平均粒径为2.2nm,略小于Pt/C催化剂,而晶格参数相对增大。通过电化学原位时间分辨红外光谱研究了乙醇在PtSn/C催化剂上的吸附和氧化过程,表明线性吸附态CO(COL)是主要的乙醇解离吸附物种,导致催化剂中毒,阻止反应继续进行;当电位增大到0.3V时,出现了乙醛和乙酸的红外吸收峰,作为乙醇解离吸附的竞争反应,乙醛和乙酸的生成有效抑制了催化剂中毒,随着电位的增大和时间的延长,生成乙酸的选择性增大;电位进一步增大至0.4V时有微弱CO2吸收峰出现,是乙醇电氧化的最终产物,主要来自于COL的氧化消耗。根据实验结果讨论了PtSn/C催化剂上乙醇的电催化氧化机理。Carbon supported PtSn catalyst （PtSn/C） was prepared by a modified polyol method and characterized by means of XRD. It was showed that the metal particle size was 2.2 nm and the unit cell parameter increased compared with Pt/C. In situ time-resolved Fourier transform infrared spectroscopy （TRFTIRS） was used to study the electrooxidation of ethanol on PtSn/C catalyst. COL was the main poison species adsorbed on the active sites to inhibit the further reaction of ethanol electrooxidation. Acetaldehyde and acetic acid were found to be the products of ethanol electrooxidation as competing reactions with ethanol dissociation when the potential was up to 0.3 V, which reduced the poisoning effect. The selectivity of acetic acid among the products was improved with the increase in the potential and reaction time. CO2, which appeared at 0.4 V, was the final product and yielded from the oxidation of COL. The catalytic mechanism of PtSn/C towards ethanol electrooxidation was analyzed based on the results.

关 键 词：直接乙醇燃料电池 PtSn/C 乙醇电氧化 时间分辨红外光谱 

分 类 号：O644.1[理学—物理化学]