Collect. Czech. Chem. Commun. 1984, 49, 2400-2409

Investigation of the mechanism of thiophene hydrodesulphurization by isotopic method

Boris S. Gudkova, Nataliya A. Gaydaya, Ludvík Beránekb and Savelii L. Kipermana

a N. D. Zelinskii Institute of Organic Chemistry, Academy of Sciences of the USSR, 117 913 Moscow, USSR
b Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6 ČSSR


The reaction of thiophene with deuterium on aluminia supported Ni-, Mo- and Ni-Mo-catalysts (laboratory samples) and Ni-W-, Ni-Mo- and Co-Mo-catalysts (commercial samples) was investigated at 150-455°C and different D2/C4H4S ratio in a closed system with internal circulation (total reactant pressure 3 kPa) and in a gradientless flow system (atmospheric pressure). Analysis of the deuterium distribution in thiophene and hydrogen sulphide and of its change in dependence on the extent of reaction revealed that thiophene hydrodesulphurization proceeds with participation of external hydrogen and not intramolecularly with participation of the β-hydrogen atoms of thiophene. This conclusion was checked also by the reaction of deuterothiophene with light hydrogen. In the analysis of the results, the fast H2 - D2 exchange with thiophene was taken into account; exchange reaction of deuterium with hydrogen sulphide was not significant.