Unraveling the differences of the reactivity of 3-methylthiophene and benzothiophene over bulk NiMoS catalysts using an experimental and kinetic modeling study

The reactivities of two model molecules, 3-methylthiophene (3MT) and benzothiophene (BT), representative of those contained in a FCC gasoline, was investigated over two Ni-promoted MoS2 (NiMoS) bulk catalysts prepared according to two synthesis procedures, a metathesis-like one (NiMoS-M) and an innovative one including an in-situ Ni promotion (NiMoS-NG). The second procedure led to smaller NiMoS particles with a narrower size distribution and higher Ni promotion rate. Differences in the activity of the catalysts were observed for the transformation of 3MT and BT. BT was more reactive than 3MT over NiMoS-M whereas the reactivity of both sulfur molecules became similar over NiMoS-NG. The kinetic modeling indicated a higher adsorption constant of 3MT over NiMoS-NG than NiMoS-M and similar adsorption constant of BT on both catalysts. The results have been interpreted taking into account the differences of the catalyst properties in relation with the mechanisms involved in the transformation of both molecules. [Display omitted] ●Influence of synthesis procedures for NiMoS catalyst properties.●Innovative synthesis of MoS2 bulk catalysts with remarkable Ni promotion.●Strong difference in reactivity of 3-methylthiophene and benzothiophene.●Importance of coupled “experimental/kinetic modeling” studies.●Importance of adsorption/reaction mechanisms of sulfur molecules for the catalyst efficiency.