Hydrogen production by partial oxidation of methanol over Au/CuO/ZnO catalysts

Abstract

Hydrogen production by partial oxidation of methanol (POM) (CH3OH + 0.5O2 → 2H2 + CO2) was examined over Au/CuO/ZnO (Au 3 wt.%, Cu 37 wt.% and Zn 60 wt.%) catalysts, prepared by the co-precipitation method. The activity of Au/CuO/ZnO catalysts has been compared with that of CuO/ZnO (Cu 40 wt.% and Zn 60 wt.%) catalysts. The catalysts were characterized by XRD, TEM and TPR analyses. The Au/CuO/ZnO catalysts are more active and exhibit higher hydrogen selectively with smaller amount of CO compared to the CuO/ZnO catalysts. The enhanced activity of Au/CuO/ZnO catalyst is due to the strong interaction between Au and CuO species as evidenced by TPR analysis. The influence of calcination temperature on the catalytic activity of Au/CuO/ZnO catalyst depends on crystalline phases of support and particle size of Au and CuO present on the catalysts. The optimum calcination temperature is 573 K. The catalytic performance at various reaction temperatures shows that at 448 K the reaction sets on with O2 completely consumed. A high hydrogen selectivity of 97.7% is attained at 523 K with 100% methanol conversion. The undesired by-product, CO is formed in very small amount throughout the temperature range studied. © 2007 Elsevier B.V. All rights reserved.