Preparation of 1,2-Propanediol via One-Pot Reaction of Propylene and Hydrogen Peroxide Catalyzed by Hollow Titanium Silicalite and Sn-β Catalyst

1,2-Propanediol is an important chemical typically synthesized from propylene oxide. In this work, 1,2-propanediol was prepared via a one-pot process starting from propylene and hydrogen peroxide, catalyzed by hollow titanium silicalite (HTS) and Sn-β in an aqueous solution. The effects of reaction conditions were investigated, and the combined HTS and Sn-β catalyst exhibited good catalytic performance for the production of 1,2-propanediol. Under optimal conditions, the hydrogen peroxide conversion and 1,2-propanediol selectivity reached 96.8% and 92.8%, respectively. In this system, HTS catalyzes the epoxidation of propylene, while Sn-β promotes the hydrolysis of the intermediate propylene oxide to form 1,2-propanediol. Thus, HTS and Sn-β cocatalyze the epoxidation-hydrolysis tandem reaction. The combined catalyst was recycled 20 times without an obvious decrease in hydrogen peroxide conversion or 1,2-propanediol selectivity, demonstrating its stable performance.