Fabrication of ordered mesoporous MoO3 for olefin catalytic hydrogenation

Abstract

Mesoporous transition metal oxides have gained an increasing interest as alternatives to precious metal catalysts for hydrogenation of unsaturated organic molecules. However, the synthesis of a highly crystalline mesoporous transition metal oxide with a high surface area and an ordered pore structure still presents a major technical challenge. Herein, we report the synthesis of a series of well-ordered mesoporous molybdenum oxide (MoO3) complexes via a nanocasting route using cubic mesoporous silica KIT-6 as a template. The catalytic activity of these materials was probed using cyclohexene hydrogenation as a model system. The as-synthesized mesoporous MoO3 materials exhibit crystalline frameworks, high surface areas up to 142 m2/g, and uniform and tunable pore sizes in the range of 6.0–12.7 nm. The mesoporous MoO3 catalysts display excellent catalytic activity with 100% conversion in 6 h, much higher than that of bulk MoO3. The mesostructure and the high surface area enable the reaction to proceed with an enhanced hydrogen spillover rate and an increased concentration of hydrogen bronze.