Development of oxide-supported nickel-based catalysts for catalytic decomposition of dimethyl sulfide

Abstract

We have developed a heterogeneous catalyst for the decomposition and removal of dimethyl sulfide used as an odorant in fuels such as city gas in residential fuel cell systems. For the dimethyl sulfide decomposition at 500 °C over various oxides such as γ-Al2O3, TiO2, ZrO2, CeO2, SiO2, and MgO, it was found that adsorption of dimethyl sulfide and other products containing sulfur components, sulfurization of metal oxides, and decomposition of dimethyl sulfide occurred. Namely, dimethyl sulfide could be removed from the reaction gas by several reactions. Furthermore, the loading of the nickel component on γ-Al2O3 as a metal component led to high decomposition performance. Based on the XRD, H2-TPR, and UV–Vis spectra analyses, after the preparation, this catalyst exists in the state of nickel oxide and nickel aluminate supported on γ-Al2O3. However, upon exposure to the dimethyl sulfide or hydrogen sulfide feed, the sulfurization reaction of nickel species proceeds, leading to the transformation of the material to nickel sulfide and the enhancement of the decomposition reaction. Furthermore, based on the results of the optimization of the nickel loading amount, we revealed that the 10 wt% supported catalyst was the best catalyst.