介孔碳化钨负载铂催化剂对甲醇氧化的电催化性能

采用硬模板法制备了介孔碳化钨(m-WC), 进一步还原铂的前驱体(H2PtCl6)得到Pt/m-WC催化剂。采用X射线粉末衍射(XRD)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)等测试手段对样品的物相、结构和形貌进行了表征。结果表明, 所制得的m-WC载体为单一的碳化钨相, 孔径为10~20 nm, Pt/m-WC催化剂中Pt的粒径约为3.4 nm, 主要以金属态形式存在, 相对比较均一的Pt纳米粒子均匀地分散在载体的表面和孔道中。电化学测试结果表明, 与普通WC载Pt催化剂(Pt/c-WC)相比, Pt/m-WC催化剂具有较大的电化学活性表面积, 对甲醇呈现出更高的电催化氧化活性和更好的稳定性。

Mesoporous Tungsten Carbide Supported Pt and Their Electro Catalytic Activity for Methanol Electro-oxidation

Mesoporous tungsten carbide supported Pt nanoparticles (Pt/m-WC) with uniform size were prepared using hard template method and H2PtCl6 as the Pt precursor. The crystal phase, structure and morphology of products were characterized with X-ray powder diffraction (XRD), transmission electronic microscope (TEM), and X-ray photoelectron spectrocope (XPS). Results show that the tungsten carbide supporter has pure tungsten carbide phase with pore size of about 10-20 nm. Pt particles (3.4 nm mean size) which are mainly in the metallic form are dispersed on the external walls and pores of m-WC. The electro-catalytic activity of the prepared Pt/m-WC towards the oxidation of methanol was investigated using cyclic voltammetry and chronoamperometry. In comparison to the common tungsten carbide supported Pt catalyst (Pt/c-WC), the Pt/m-WC catalysts exhibits high electrocatalytic activity, strong anti-poisoning ability and good stability.