Modification of acid–base properties of alkali metals containing catalysts by the application of various supports

Four different supports, SiO2, Al2O3 and Nb2O5 (hydrated and dehydrated) were impregnated with alkali metal acetates to obtain alkali-modified materials. The textural parameters of the samples were estimated on the basis of XRD and IR measurements and nitrogen adsorption/desorption method. The acid–base properties of the obtained materials were tested in the cyclisation of acetonylacetone and decomposition of 2-propanol. Moreover, the prepared catalysts were used in the sulphurisation of methanol towards methanethiol and dimethyl sulphide production, which appeared a well-tested reaction and exhibits the commercial aspect—environmentally friendly production of thiol. The modification of both niobia supports with alkali metal species creates acid–base catalysts highly selective in the methanethiol production, whereas the impregnation of silica and alumina with these species leads to the generation of basicity.