Fabrication and kinetics of Cu/MgO catalysts for selective hydrogenation of methyl benzoate to benzyl alcohol

Abstract

Highly efficient transformation of methyl benzoate to benzyl alcohol has been attracting attention due to its fascinating basic research value and fundamental application prospects. Cu/MgO catalysts were fabricated by coprecipitation, and the resulting catalysts were investigated to discover their textural and structural properties and catalytic performance in selective hydrogenation of methyl benzoate to benzyl alcohol. The Cu/MgO catalysts exhibited a high dispersity of metallic copper, excellent textural properties and reducibility, and a high Cu⁺/Cu⁰ ratio. The catalysts were found to be active and selective for hydrogenation of methyl benzoate to benzyl alcohol with a conversion of methyl benzoate of 98.0% and a selectivity to benzyl alcohol of 97.8% at 80 °C. There was no significant change in the textural and structural properties and catalytic performance after 6 cycles of evaluation, indicating reliable stability. The surface synergy between copper species and Lewis basic sites of MgO may promote the adsorption and activation of hydrogen and carbon-based species, leading to high catalytic activity. A plausible reaction mechanism was deduced and the intrinsic kinetics was analyzed to calculate the reaction rate accordingly. This work may provide some insights into the development of copper-based catalysts for the selective hydrogenation of methyl benzoate to benzyl alcohol.