Adsorption and reactivity of some sulphur-containing compounds on a mixed-oxide « cobalt molybdate » type catalyst

¹ Department of Chemistry and Applied Chemistry, Salford University, Salford, M5 4WT, France.
² Department of Chemistry, The Queen’s University, Belfast, BT9 5 AG, France.

Abstract

Adsorption-desorption isotherms for hydrogen sulphide, dimethyl sulphide, ethanethiol and thiophene on a cobalt oxide-molybdenum oxide-γ-alumina catalyst are reported. The adsorption of dimethyl sulphide and thiophene is interpreted as physical adsorption only. Isosteric heats of thiophene adsorption at various coverages were between -18.5-34.7 kj mol^-1, and catalyst pore size distributions, calculated from this data by the Kelvin equation, are reported. Appreciable amounts of hydrogen sulphide and of ethanethiol were retained on the surface even after prolonged outgassing, these quantities of gas chemisorbed were used to estimate the number of active sites on the catalyst surfaces. A quantitative kinetic study of the thermal decomposition of adsorbed ethanethiol was made.

Résumé

Les travaux exposés dans cet article concernent les adsorptions et désorptions des H₂S, (CH₃)₂S, C₂H₅SH et C₄H₄S sur un catalyseur CoO — MoO₃ — γAl₂O₃.