Activity and selectivity of platinum-copper bimetallic catalysts supported on mordenite for glycerol hydrogenolysis to 1,3-propanediol

Biomass derived glycerol is considered an ideal feedstock with a prospective to be converted into a number of valuable compounds. Catalytic glycerol hydrogenolysis to produce 1,3-propanediol is one of the pioneering biosustainable pathways. Bimetallic Pt-Cu catalysts supported on H-mordenite were synthesized with various copper loadings and applied in the selective glycerol hyrogenolysis to 1,3-propanediol in a continuous fixed bed reactor performed in vapor phase under atmospheric pressure. Several techniques such as XRD, ICP-AES, NH₃-TPD, Pyr FTIR, BET, TPR, HR-TEM, XPS, and solid state NMR were employed to characterize the physical and chemical properties of Pt-Cu/Mor catalysts. A detailed reaction parametric study has been carried out. The results designated that well dispersed Pt-Cu catalysts with small particle size, supported on a Brønsted acidic H-mordenite with a multiple pore system and strong bimetallic phase-support interaction, promote the selectivity to 1,3-propanediol. Over the Pt-Cu/Mor catalyst of optimum composition (2% Pt and 5% Cu by weight) and under the optimum reaction conditions (210 °C, H₂ flow rate of 80 mL min^-1, and gly concentration of 10 wt %), the glycerol conversion and 1,3-PD selectivity reached 90% and 58.5%, respectively. Structural characterizations and reusability of the Pt-5Cu/Mor catalyst were also performed. With evident advantages of selective C-O hydrogenolysis with low C-C cleavages, the bimetallic Pt-Cu/Mor catalysts hold great potential as high-performance catalysts for glycerol conversion to 1,3-propanediol.