Catalytic Activities of Various Solid-Acid Catalysts for the Cracking of Ethanethiol

Abstract

The catalytic cracking of ethanethiol on various solid catalysts was investigated by the use of a pulse reactor. It was found that the active catalysts for the cracking of ethylmercaptane were not only NH4Y–zeolite, solid phosphoric acid (SPA) and silica-alumina (SA) which have the Brönsted acid sites, but also Al2O3 and alkali ion-exchanged zeolites, MeY (Me=Li, Na, K, Rb, Cs) which have scarcely the Brönsted acid sites. However, the solid bases such as CaO and MgO did not show the activity for the cracking of.' ethanethiol. The cracking products of ethanethiol on NH4Y, SPA, SA and MeY were only ethylene and hydrogen sulfide but, on Al2O3, the significant amounts of diethylsulfide were formed together with ethylene and hydrogen sulfide. On the other hand, the catalytic cracking of ethylmercaptane on NH4Y, SPA, SA and Al2O3 except MeY were poisoned by pyridine. The catalytic activities of NH4Y and SPA for the cracking of both ethanethiol and cumene decreased with the increase of the calcination temperature of the catalysts. From these results described above, it was concluded that the active sites of NH4Y, SPA and SA for the cracking of ethanethiol are the Brönsted acid sites but the active sites of Al2O3 and MeY differ from the Brönsted acid sites. Active sites of Al2O3 and MeY for the reaction were further discussed. © 1973, The Chemical Society of Japan. All rights reserved.