Studies of Catalytic Cracking of Organic Sulfur Compounds over Solid Acid Catalyst (Part 9):Dehydrosulfurization of Ethanethiol over Alkali Metal Zeolite Catalysts

The dehydrosulfurization of ethanethiol over various alkali metal zeolite catalysts was studied. The catalytic activity of NaY zeolite was little affected by the exchange of sodium ion with other alkali metal ions (Li, K, Cs and Rb). The catalytic activity of sodium zeolite was dependent on the types of zeolite (NaX, NaY and NaA), and the order of its catalytic activity was NaX>NaY>NaA. When NaY and NaA were used, the dehydrosulfurization products were only ethylene and hydrogen sulfide. In the case of dehydrosulfurization of ethanethiol on NaX, the products were ethylene, hydrogen sulfide and a substantial amount of diethyl sulfide which was formed by disproportionation of ethanethiol. Furthermore, discussions were made on the active sites of alkali metal zeolite catalysts, and it was concluded that they were the alkali metal ions and the oxygen anion of skeletal structure of zeolite. In the light of the nature of the active sites, the reaction mechanisms were also proposed.