NiW catalyst modified with C12A7-H- and its promotion to hydrogenation selectivity of hydrodesulfurization

[Ca24Al28O64](4+)center dot 4(H-) (abbreviated as C12A7-H-) powder containing H- species was synthesized to modify NiW catalyst. The incorporation of C12A7-H- increases the reaction rate constants and turnover frequencies of NiW catalysts in hydrodesulfurization (HDS) of dibenzothiophene (DBT). The characterization results show that the introduction of C12A7-H(- )promotes the reducibility of NiW catalysts, resulting in higher sulfidation degree and more Ni-W-S species. In spite of the fact that rim/edge sites ratios and Lewis acid sites are decreased, the introduction of C12A7-H- still increases the hydrogenation/direct desulfurization ratios of NiW catalysts in HDS of DBT. Furthermore, higher HDS rates of C12A7-H- modified NiW catalysts are also observed in HDS of 4,6-dimethyldibenzothiophene. These can be attributed to C12A7-H- material that may transfer active H species to NiW catalysts and thereby promote the hydrogenation selectivity of NiW catalyst.

Automated summary

The incorporation of C12A7-H- in NiW catalysts enhances the reaction rate constants and turnover frequencies in the hydrodesulfurization of dibenzothiophene. This is due to the promotion of reducibility and increased sulfidation degree by C12A7-H-, leading to higher hydrogenation selectivity despite a decrease in rim/edge sites ratios and Lewis acid sites. Furthermore, C12A7-H- modified NiW catalysts also exhibit higher HDS rates in 4,6-dimethyldibenzothiophene, attributed to the transfer of active hydrogen species and promotion of hydrogenation selectivity.