Abstract
Supported catalysts of copper and silver were prepared in this research for the partial oxidation of methanol (POM) reaction. We hope to develop a low temperature and low CO contamination POM process of hydrogen production, and to study effects of metal, support and temperature on reaction activity and product selectivity.Copper catalysts (Cu/ZnO-Al2O3) were prepared by coprecipitation and sequential precipitation methods. The copper dispersion (DCu) was significantly affected by the preparation method and the pH of copper solution. The coprecipitation method and a solution with pH ~ 7 was preferred for preparation of high DCu catalysts. In activity measurements, the methanol conversion increased with DCu and reaction temperature, and produced H2、H2O、CO2 and CO. The light-off temperature of copper catalysts was found at 175 ℃.Silver catalysts were prepared by coprecipitation (Ag/ZnO) and incipient wetness (Ag/Al2O3、Ag/ZnO-Al2O3) methods. Silver catalysts were generally active at T < 175 ℃, but their activity and selectivity varied with kind of support. Ag/ZnO catalyst exhibited high methanol conversion and hydrogen selectivity. Al2O3-supported silver catalysts (Ag/Al2O3、Ag/ZnO-Al2O3) displayed high yields of H2O、HCHO and HCOOCH3. Besides, a POM reaction mechanism had been proposed to account the effects of support、temperature and metal on the reaction activity and the product distribution.