Fuel, Vol.136, 185-193, 2014
Deposition of WO3 on Al2O3 via a microwave hydrothermal method to prepare highly dispersed W/Al2O3 hydrodesulfurization catalyst
A microwave hydrothermal method was developed to deposit WO3 on Al2O3 for rapidly preparing W/Al2O3 hydrodesulfurization (HDS) catalysts with both high tungsten dispersion and weak tungsten-alumina interaction. The catalysts were characterized by XRD, XPS, N-2 adsorption, H-2-TPR, NH3-TPD and HRTEM; their activity was tested by HDS of dibenzothiophene. Compared to the previous hydrothermal deposition method, the microwave hydrothermal method can further increase the dispersion of tungsten and attain the similar weak tungsten-alumina interaction, leading to the shorter and similar stacked WS2 and hence higher HDS activity, whereas the hydrothermal period is dramatically reduced from 12 h to 15 min. Moreover, this method can highly disperse more tungsten on alumina than the hydrothermal deposition and impregnation methods. It is attributed to the rapid nucleation and inhibited growth of WO3, and the enhanced mobility induced by microwave hydrothermal conditions. The significance of this method lies in its simplicity and efficiency for preparing tungsten-based catalysts with superior HDS activity. (C) 2014 Elsevier Ltd. All rights reserved.