采用调变的多元醇法制备了高分散的Pt/C,PtRu/C和Ru/C电催化剂.XRD计算结果表明,PtRu/C电催化剂的平均粒径和合金度分别为2.2 nm和71%.采用电化学方法和原位傅里叶变换红外反射光谱方法(in situFTIRS)研究了甲醇在3种电催化剂上的吸附氧化过程,发现PtRu/C对甲醇的催化活性明显高于Pt/C,Ru的加入一方面影响了甲醇在Pt上的解离吸附性能,另一方面提供了Ru-OH物种,从而抑制了低电位下电催化剂中毒.红外光谱研究结果表明,线性吸附态CO(COL)是主要毒化物种,反应产物主要是CO2,还有少量的甲酸甲酯.根据实验结果讨论了甲醇在PtRu/C电催化剂上的氧化机理.A modified polyol process was used to prepare Pt/C,PtRu/C and Ru/C electrocatalysts.Calcula-ted from XRD patterns,the mean particle size of PtRu/C electrocatalyst was 2.2 nm and the percentage of Ru alloyed was 71%,respectively.Adsorption and electro-oxidation progress of methanol on PtRu/C electrocatalyst was investigated by in situ FTIRS,combined with electrochemical experiments.It is revealed that the activity of PtRu/C electrocatalyst for methanol oxidation was much higher than that of Pt/C.Addition of Ru in PtRu/C electrocatalyst changed the characteristic of methanol adsorption,and Ru-OH species could oxidize linear bonded CO(CO_L) at a lower potential,thus inhibited the catalyst poisoning.In addition,from FTIRs results,CO_L was evidently identified to the main poisonous species and the major product was CO_2.Methyl formate was also identified.Based on these results,the mechanism of methanol oxidation was discussed.厦门大学固体表面物理化学国家重点实验室开放课题(批准号:200304)资
