REACTIONS OF ALCOHOLS WITH HYDROGEN-SULFIDE ON ZEOLITES - PART 7 - THE EFFECT OF BRONSTED ACIDITY OF FAUJASITE-TYPE ZEOLITES ON METHANOL HYDROSULFURIZATION

The reaction between methanol and hydrogen sulphide towards methanethi ol and dimethyl sulphide was studied on MNaY, MNaX HNaX and MHNaY zeol ites (M = Li, K, Rb, Cs). A substantial influence of the nature and st rength of active centres on the activity of zeolites and the yield of products was found. A low Bronsted acidity and a high basicity of cata lysts favour the hydrosulphurisation process. A decrease of the zeolit e acidity strength causes the growth of thiol and the decrease of sulp hide formation. High strength of Bronsted acid sites leads to high con version of methanol to hydrocarbons and low activity in the hydrosulph urisation reaction. An FT IR spectroscopic study showed the difference in the reagents and by-products adsorption depending on the strength of the acidic centres and its influence on the reaction pathways. (C) 1998 Elsevier Science B.V. All rights reserved.