Thiophene Hydrodesulfurization Catalysis over Transition Metals Supported on Mesoporous Materials

Abstract

Hydrodesulfurization (HDS) is a commonly used industrial process for removing sulfur from fuel. Fuels containing sulfur are treated with hydrogen gas in the presence of a catalyst, producing sulfur-free hydrocarbons for cleaner fuel. In this study, the reactivity of several potential catalysts containing transition metals on mesoporous supports, such as 1% Zn and 10% Zn on SiO_(2 ), 0.5% Ni on SrTiO_(2 ), and 5% Co on CeO_(2 ), toward the hydrodesulfurization of thiophene were studied using a gas-chromatograph based mini flow reactor. Thiophene is used as the probe molecule because it is found in natural petroleum and is simple enough probe molecule to obtain mechanistic molecular-level information. The reactivity of thiophene on commercially available silica supported CoMo catalyst was studied and compared with the results of the catalysts of interest. Two main goals of this study were to identify a catalyst that could produce sulfur free hydrocarbons as or more efficiently than the commercial catalyst. Unfortunately, CoMo had the highest conversion rate with 35%; however, 5% Co on CeO_(2 )was not far behind at 22.3%. The 0.5% Ni on SrTiO_(2 )catalyst had a much lower conversion rate of 6.9%, and neither Zn on SiO_(2 )catalysts were successful in the hydrodesulfurization of thiophene. This research project on hydrodesulfurization will help in the current need for cleaner fuels with a new generation of catalysts with higher reactivity.