Surface hydrophobization of zeolite enables mass transfer matching in gas-liquid-solid three-phase hydrogenation under ambient pressure
Shuai Wang, Riming Hu, Jianyu Ren, Yipin Lv, Lianghao Song, Huaiqing Zhao, Xuchuan Jiang, Daowei Gao, Guozhu Chen
Abstract
Abstract Attaining high hydrogenation performance under mild conditions, especially at ambient pressure, remains a considerable challenge due to the difficulty in achieving efficient mass transfer at the gas-liquid-solid three-phase interface. Here, we present a zeolite nanoreactor with joint gas-solid-liquid interfaces for boosting H 2 gas and substrates to involve reactions. Specifically, the Pt active sites are encapsulated within zeolite crystals, followed by modifying the external zeolite surface with organosilanes. The silane sheath with aerophilic/hydrophobic properties can promote the diffusion of H 2 and the mass transfer of reactant/product molecules. In aqueous solutions, the gaseous H 2 molecules can rapidly diffuse into the zeolite channels, thereby augmenting H 2 concentration surround Pt sites. Simultaneously, the silane sheath with lipophilicity nature promotes the enrichment of the aldehydes/ketones on the catalyst and facilitates the hydrophilia products of alcohol rediffusion back to the aqueous phase. By modifying the wettability of the catalyst, the hydrogenation of aldehydes/ketones can be operated in water at ambient H 2 pressure, resulting in a noteworthy turnover frequency up to 92.3 h −1 and a 4.3-fold increase in reaction rate compared to the unmodified catalyst.