Catalytic performance of sucrose-derived CMK-3 in oxidative dehydrogenation of propane to propene

CMK-3 carbon replica was synthesized by carbonization of sucrose introduced to the pore system of a SBA-15 hard template followed by dissolving SiO2 with HF. The material with a stable hexagonal structure and an expanded surface area (SBET = 1287 m2/g) was obtained. TG measurements showed that CMK-3 type mesoporous carbon started to be intensively oxidized by molecular O2 above 723 K. This carbon sample was tested as a catalyst of dehydrogenation of propane to propene under oxidative (O2:C3H8 = 0.25, 0.50 and 1.00) and non-oxidative (O2:C3H8 = 0.00) conditions in the temperature range from 573 to 873 K. The propene yield increased with rise in the reaction temperature, however above 573 K the formation of side-products (C2H6, C2H4, CH4 and H2) was observed. Moreover, coke was deposited on the catalyst surface. A decrease in the mass of a catalyst bed after the catalytic runs suggested the participation of oxygen in burning of deposited and bulk coke. The surface composition of a spent catalyst was investigated by XPS and TPD analysis. The changes in the concentration of oxygen functional groups, caused by the catalytic reaction, were observed regardless of a reaction temperature and feed composition.

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► CMK-3 carbon replica exhibits high catalytic activity in dehydrogenation of propane.
► Reaction temperature and feed composition strongly influence catalytic performance.
► Changes in surface composition are observed during the catalytic process.
► Oxygen-containing groups play a crucial role in the propane conversion.