Influence of the carrier and composition of active phase on physicochemical and catalytic properties of CuAg/oxide catalysts for selective hydrogenolysis of glycerol

摘要

The aim of the present study is to investigate the influence of the support and composition of the active bimetallic phase on both the physicochemical and catalytic properties of catalysts for use in glycerol hydrogenolysis reaction. Two series of catalysts with different amounts of copper oxide and/or silver supported on Al2O3 or TiO2 oxides were prepared. To determine the physicochemical properties of the catalysts, the following techniques were used: Brunauer-Emmett-Teller, reactive N2O adsorption, X-ray diffraction, and temperature-programmed reduction TPR-H-2. Physicochemical characterization revealed that addition of silver modifies the redox properties of the catalysts containing copper oxide and influences their specific surface area. It was found that the type of carrier determines the catalytic activity and selectivities for desired products, strongly influencing their distribution. The Al2O3-supported catalysts were much more selective for 1,2-propanediol, whereas 1-propanol was the main reaction product for the titania-supported catalysts. The best catalysts (6Cu/Al and 2Cu/Ti) achieved 38 % glycerol conversion with 71 % selectivity for 1,2-propanediol and 44 % conversion with 62 % selectivity for 1-propanol, respectively.