Abstract
Partial oxidation of methanol (POM) to produce H-2 was investigated over Au-Cu/TiO2 and Au-Cu/TiO2-Fe2O3 catalysts. The catalysts were prepared by deposition-precipitation method and characterized by XRD, TEM, HRTEM, ICP-AES, TPR, NH3-TPD and XPS analyses. Detail study on the Au-Cu/TiO2-Fe2O3 catalysts was performed to optimize Ti/Fe ratio, pH during preparation of the catalyst, calcination temperature and reaction temperature. The Au-Cu/TiO2-Fe2O3 catalyst with Ti/Fe = 9/1 atomic ratio is more active and exhibits higher methanol conversion compared to the Au-Cu/TiO2 catalyst. The higher activity of Fe-containing catalyst was attributed to the ability to supply reactive oxygen, thereby stabilize active gold species (Au delta+) in the catalyst. Studies on the optimization of pH during preparation of the Au-Cu/TiO2-Fe2O3 catalyst and calcination temperature showed that the catalyst prepared at pH 7 and dried at 373 K (uncalcined) exhibited higher activity. The catalytic performance at various reaction temperatures shows that both methanol conversion and hydrogen selectivity are increased with increasing the temperature. A small increase in CO selectivity was observed beyond 523 K, which is due to the decomposition of methanol and reverse water gas shift at high temperatures. (C) 2009 Elsevier B.V. All rights reserved.