Mesoporous Gamma-Alumina-Supported Mo Catalysts: Effect of Calcination Temperature

Mesoporous gamma-Al2O3-supported Mo oxides precursors were prepared by one-step hydrolysis method without organic template at different calcination temperatures (MoOx/gamma-MA-T) from 400 to 700 degrees C. Then MoS2 catalysts (MoS2/gamma-MA-T) were obtained from the precursors through in-situ sulfurization and applied for hydrodesulfurization (HDS) of dibenzothiophene (DBT). Effects of precursors calcination temperature on physicochemical properties and catalytic performances of catalysts were systematically investigated. With the increase of calcination temperature, the strength of metal-support interactions and slab lengths of MoS2 increased. The slab stacks were inhibited by the strengthened strong interaction, leading to the reduction of edge/rim sites ratio that are favour for the HDS reaction. Appropriate calcination temperature (500 degrees C) could make the MoS2/gamma-MA-500 possess favourable pore structure, particle dispersion, and edge/rim sites ratio, which were conducive to the mass transfer process of reactants and products, and lowered the carbon deposition rate, thus improving its catalytic activity, stability and direct hydrogenolysis desulfurization selectivity.

Automated summary

The effects of different precursor calcination temperatures on the physicochemical properties and catalytic performances of catalysts were investigated. It was found that an appropriate calcination temperature could improve the catalyst's pore structure, particle dispersion, and edge/rim sites ratio, leading to enhanced catalytic activity and stability.