Remarkable activity of Pd catalyst supported on alumina synthesized via a hydrothermal route for hydrogen release of perhydro-N-propylcarbazole

Abstract The investigation of dehydrogenation catalysts to achieve rapidly hydrogen release of Liquid Organic Hydrogen Carriers (LOHCs) are of crucial importance for large-scale applications. The catalyst supports with bulk surface area and decent acid-base nature is a key parameter for catalyst to improve its catalytic performance as well as reduce precious metal dosage. Herein, alumina was chosen as a support for Pd loading and prepared through hydrothermal route at different temperatures. The morphology and surface acid property of the alumina supports were investigated in detail. The results revealed that the hydrothermal temperature had a closely effect on the morphology, surface acidity and specific surface area of alumina, resulting in a further impact on Pd dispersion and particle size associated tightly with catalytic activity of Pd/Al2O3. The catalyst with 1 wt% Pd loaded on alumina carrier prepared via hydrothermal treatment at 120 °C showed the best catalytic performance for dehydrogenation of perhydro-N-propylcarbazole (12H-NPCZ). Full dehydrogenation with 100% conversion to N-propylcarbazole (NPCZ) could be achieved after 360 min at 180 °C and 101 kPa, which is higher than that of commercial 5 wt% Pd/Al2O3 catalyst. The catalyst has potential commercial application value in large-scale application of LOHC technology.