Tuning Biphasic Catalysis Reaction with a Pickering Emulsion Strategy Exemplified by Selective Hydrogenation of Benzene

Although organic/aqueous biphasic catalysis reactions are widely used, it is difficult to effectively control their reaction process. Here we develop a solid particles-stabilized emulsion (Pickering emulsion) strategy to address this limitation. A challenging biphasic reaction, selective hydrogenation of benzene to cyclohexene, was investigated as a case. The developed Pickering emulsion system exhibited higher catalysis efficiency and selectivity than the conventional biphasic reaction system even under mild stirring. The cyclohexene selectivity and yield in the Pickering emulsion system reached as high as 51.2 % and 43.3 %, respectively. More importantly, the findings presented here demonstrate the feasibility that the reaction rate and selectivity of challenging biphasic reactions can be regulated by the rational adjustment of Pickering emulsion parameters including emulsion droplet size, droplet distance as well as emulsion type, which is otherwise unattainable for conventional biphasic reaction systems.