Preparation of PtRu/WO3–C by intermittent microwave method with enhanced catalytic activity of methanol oxidation

Abstract

The hybrid materials of WO3 and carbon (WO3–C) were prepared by intermittently microwave-pyrolysis using ammonium tungstate and carbon black (XC-72, Cabot Corp.) as the precursor. PtRu nanoparticles were then deposited on WO3–C and C by microwave-assisted polyol process. Transmission electron microscope analysis suggested that WO3 and PtRu particles were uniformly distributed on carbon. The effect of WO3 in the supporting materials and heat treatment on its microstructure and catalytic activity was systematically investigated. Electrochemical experiments showed that PtRu/WO3–C with 5 % WO3 in supporting materials had the best catalytic activity and stability for methanol oxidation. Furthermore, the peak current densities of methanol oxidation can be further improved from 11.23 mA cm−2 for PtRu/C to 19.90 mA cm−2 for PtRu/5 % WO3–C-A after heat treatment in N2 at 500 °C. The addition of WO3 in PtRu/C catalyst can significantly improve its performance on methanol oxidation, especially after heat treatment at 500 °C. (a) Pt–Ru/C, (b) Pt–Ru/Cwith 5 % WO3and (c) Pt–Ru/C with 5 % WO3 after heat treatment.