Preparation and characterization of novel Ti0.7W0.3O2–C composite materials for Pt-based anode electrocatalysts with enhanced CO tolerance

Abstract

Ti-based electroconductive mixed oxides were deposited onto activated carbon by using three different sol–gel-based multistep synthesis routes. As demonstrated by X-ray diffraction, high crystallinity of the tungsten-loaded rutile was achieved by a sequence of annealing in inert atmosphere at 750°C and a short reductive treatment at 650°C. Formation of the rutile phase on the carbon support before the high temperature treatment has been proved to be the prerequisite for complete W incorporation into the rutile lattice. The structural and compositional properties of the mixed oxides were explored by transmission electron microscopy, temperature programmed reduction and X-ray photoelectron spectroscopy. Anode electrocatalysts were formulated by loading the composite of the activated carbon and the Ti-based electroconductive mixed oxides with 40wt% Pt. Enhanced CO tolerance along with considerable stability was demonstrated for the electrocatalyst prepared using the Ti0.7W0.3O2–C composite material with high degree of W incorporation.