Fabrication of Pd/SiO2 with Controllable Wettability for Enhanced Catalytic Hydrogenation Activity at Ambient H2 Pressure

Abstract

AbstractThe wettability had great influence on the catalytic performance of heterogeneous catalyst. In this manuscript, relationship between wettability and catalytic performance was studied by the preparation of Pd/SiO2 with controllable wettability employing surface‐bonded vinyl as the reductant. The surface‐bonded vinyl ensured the reduction of PdCl2 on the hydrophobic surface of SiO2 to afford the hydrophobic Pd/SiO2. The wettability of the catalysts could be adjusted by changing the content of phenyl on the surface. The catalysts were characterized by solid‐state CP/MAS NMR, TEM, HRTEM, XPS, XRD and ICP‐AES as well as water droplet contact angles. The catalysts showed zero‐order kinetics for the hydrogenation of styrene under mild conditions. The activation energy for this reaction was measured by the Arrhenius formula. The wettability was proved to influence the reaction activity by changing the activation energy. The increase in hydrophobicity led to higher activity by decreasing the activation energy for hydrogenation of styrene to ethylbenzene.