Selective oxidation of CO in hydrogen rich gas over platinum–gold catalyst supported on zinc oxide for potential application in fuel cell

Abstract

A series of gold zinc oxide catalysts were prepared using a coprecipitation procedure, and their performance for catalytic oxidation removal of CO from H 2 rich gas was investigated in a fixed bed reactor. The results showed that its optimum content of Au was 1.5 wt.% in ZnO, Au(1.5)/ZnO. The effect of calcining temperatures on Au(1.5)/ZnO performance for removal of CO showed that the ideal calcining temperature was 300 °C, Au(1.5)/ZnO-300. During 500 h continuous experimental investigation for Au(1.5)/ZnO-300 to remove CO selectively at 80 °C, its performance was slightly decreased when the time on stream was over 350 h. When small amounts of platinum were added to Au(1.5)/ZnO-300, its stability was improved. However, when the content of platinum in Au(1.5)/ZnO-300 was over 1.0 wt.%, the selectivity for removal of CO for Au(1.5)–Pt/ZnO-300 was lowered with increasing content of Pt. The ideal composition for Au(1.5)–Pt/ZnO-300 was 1.0 wt.% Pt, Au(1.5)–Pt(1.0)/ZnO-300.