Structure and electrochemical activity of WOx-supported PtRu catalyst using three-dimensionally ordered macroporous WO3 as the template

PtRu/WOx catalyst is prepared in a polyol process with three-dimensionally ordered macroporous (3DOM) WO3 as the template in combination with an ammonia-leaching treatment. The morphology, composition and structure of the prepared catalysts are characterized by scanning transmission electron microscopy, energy dispersion X-ray spectroscopy, N2 adsorption, X-ray photoelectron spectroscopy and X-ray diffraction. The electrochemical activities are evaluated by linear sweep voltammetry, cyclic voltammetry, and chronoamperometry measurements in combination with in situ IR reflection absorption spectroscopy (IRRAS). The composition and particle size of the PtRu/WOx catalyst are similar to those of the PtRu catalyst prepared without the 3DOM WOx template, and both of the catalysts have a uniform element distribution, however, the PtRu/WOx catalyst has a more porous structure and greater metallic Pt proportion due to the support role of the residual WOx template and the interaction between WOx and PtRu nanoparticles. Electrochemical and in situ IRRAS measurements indicate that the PtRu/WOx catalyst has a greater electro-catalytic activity for methanol oxidation than the PtRu catalyst due to the assisting catalytic role of WOx and mass transport benefit of the porous structure.