Catalytic decomposition of methanethiol to hydrogen sulfide over TiO2

Catalytic decomposition of methanethiol to hydrogen sulfide over TiO2

Type	Journal Article
Author	Takashi Mukoyama
Author	Naohiro Shimoda
URL	http://www.sciencedirect.com/science/article/pii/S0378382014004809
Volume	131
Pages	117-124
Publication	Fuel Processing Technology
Date	March 2015
Abstract	Catalytic direct decomposition of methanethiol into hydrogen sulfide on various metal oxides without hydrogen addition is a novel desulfurization process for fuel cell systems. Researchers decomposed methanethiol into hydrogen sulfide over several metal oxide catalysts at 300 °C. Metal oxide catalysts used in their study decomposed methanethiol completely at 500 °C. However they would be sulfurized immediately by the decomposed products. Among them, titania (TiO2) catalyst exhibited significant methanethiol decomposition activity, and was hardly sulfurized. The methanethiol conversion of TiO2 catalyst depended on the specific surface area. Hydrogen sulfide and dimethyl sulfide were produced with the same amount at below 250 °C. The methanethiol seems to be decomposed by the following equation at low temperature range: 2CH3SH → H2S + (CH3)2S. In contrast, hydrogen sulfide and methane were produced as gas phase products and carbon species were also formed on TiO2 surface above 400 °C. The methanethiol seems to be decomposed by the following equation at high temperature range: 2CH3SH → 2H2S + CH4 + C. Researchers determined that the direct decomposition of methanethiol on TiO2 surface proceeds via different reaction pathways depending on the reaction temperatures.