Deactivation study of supported Pt catalyst on glycerol hydrogenolysis

• Several supported Pt catalysts were prepared and tested in the liquid-phase glycerol hydrogenolysis.
• Used catalysts lost some of the surface area associated to graphitized organic deposits.
• Oligomerization of acetol on the acid sites of the support is the main cause of the loss of 1,2-PDO yield.
• Pt/ZnO catalysts presented the best behavior in the liquid-phase glycerol hydrogenolysis.

Different Pt-based systems (5% by weight) were obtained through impregnation of chloroplatinic acid on Al2O3, CeO2, La2O3 and ZnO. The solids were tested for glycerol hydrogenolysis. Results showed that metal sites are needed both for dehydration of glycerol and subsequent reduction to 1,2-propanediol (1,2-PDO). Moreover, as the reaction proceeds there is a progressive decrease in 1,2-PDO yield as a consequence of acetol oligomerization which already takes place at temperatures as low as 150 °C. Among all tested supports, ZnO was the one exhibiting better characteristics for glycerol selective transformation into 1,2-PDO as a result of the combination of the appropriate surface acidity, limited deactivation and stability under hydrothermal working conditions.

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