制备条件对甲醇电氧化催化剂PtRu/CAs性能的影响

本文利用液相浸渍还原的方法制备了PtRu/C催化剂, 其中Pt质量百分含量分别为15%, Pt和Ru的原子比为2:1. 研究了金属前驱体于不同介质（CH3COOH、H2O及CH3COONa）中浸渍所制备的催化剂组成, 结构以及活性方面的区别. 同时比较分析了不同载体（碳纳米管CNTs与碳气凝胶CAs）对催化剂性能的影响. 催化剂的物化性质通过XRD, TEM以及EDS来表征, 并采用循环伏安法测试其电化学性能. 结果表明以碳气凝胶为载体,均匀分散于异丙醇与水混合溶液后, 加入CH3COOH, 使金属前驱体在酸性介质中浸渍, 再用NaOH调节pH值至碱性, 同时生成CH3COONa作为稳定剂, 然后再用NaBH4还原所制得的催化剂具有更高的电催化活性, 其峰电流密度达到38.24 mA/cm2, 远高于本文中在其他条件下制备的催化剂.

Effect of Preparation Conditions on the Catalytic Performances of PtRu/CAs Catalysts for Methanol Electro-oxidation

The impregnation method was applied to prepare the platinum – ruthenium (Pt-Ru) catalysts in which the content of Pt was 15%, and the atomic ratio of Pt and Ru was 2:1. The properties of the catalysts prepared with varied impregnated mediums (acetic acid, sodium acetate and water) and different carriers (carbon nanotubes and carbon aerogels) were studied in detail. The X-ray diffractometry(XRD) and transmission electron midroscopy(TEM) were used to observe the surface morphology of above Pt-Ru catalysts. The Energy Dispersive X-ray Spectrum(EDS) was used to analyze the composition of catalysts. The electrochemical performance of the catalysts was examined by cyclic voltammetry with a glassy carbon working electrode in a solution of 1.0 mol/L CH3OH and 0.5 mol/L H2SO4. In above all catalysts, the catalyst prepared with the metal precursor impregnated in CH3COOH and carbon aerogels as a carrier has the highest electrocatalytic activity. The peak current density gets to 38.24 mA/cm2, which is much higher than the rest of the catalysts prepared with other conditions in this paper.