Preparation of 1, 2-Hexanediol by epoxidation of 1-Hexene catalyzed by functionalized ionic liquid supported modified HPW/UIO-66

Abstract The industrial application of 1, 2-hexanediol production via epoxidation of 1-hexene remains limited due to the low catalytic activity and difficult separation of conventional catalysts. To address these challenges, we report the development of a reusable and environmentally benign green catalyst. A composite catalyst, AIL-HPW/UIO-66, was synthesized via a solvothermal method followed by immobilization of a functionalized ionic liquid. Characterization results reveal that the AIL-HPW/UIO-66 catalyst modified with a sulfonic acid-functionalized quaternary ammonium ionic liquid (AIL(Tf)) exhibits superior catalytic performance. The synergistic effect between the sulfonic acid groups and the quaternary ammonium chains significantly enhances the density of Brønsted acid sites. Additionally, the catalyst acquires phase-transfer capability and moderate hydrophobicity, promoting the mass transfer of 1-hexene in the biphasic water-organic system. Under optimized reaction conditions (25°C, 7 h), the yield of 1,2-hexanediol reached 87.4%, with less than 2.5% loss in catalytic activity after five consecutive cycles.