Study on highly efficient methylcyclohexane dehydrogenation over Pt/NPC catalysts by internal electric heating

Developing highly efficient hydrogen storage technology plays a key role in large-scale hydrogen energy applications. As an ideal organic liquid hydrogen storage medium, methylcyclohexane (MCH) has the advantages of high mass hydrogen storage density, safe and convenient storage and transportation, etc. However, the dehydrogenation process still faces problems such as high reaction temperature and low efficiency. The key to solving the above problems is to develop efficient dehydrogenation catalysts and introduce effective process intensification. Herein, a series of N-doped porous carbon (NPC) with different calcination temperature supported Pt catalysts (Pt/NPC) were prepared by wet impregnation method, and their effects on the MCH dehydrogenation were studied by novel internal electric heating (IEH) mode. The results show that the Pt2+ proportion firstly increases and then decreases with the increment of the NPC calcination temperature, and reaches the maximum value at 550℃. An approximately linear positive correlation between the Pt2+ proportion and the reaction rate of MCH dehydrogenation is obtained. Moreover, the hydrogen evolution rate over optimized Pt/NPC catalyst under IEH mode was about 3 times of that under conventional external heating (CEH) mode. In combination with temperature measurements, the calculation of reaction heat and heat transfer, catalytic evaluation and operando MCH-FTIR characterization, the improved catalytic performance was ascribed to high heating rate and heat transfer rate, as well as strengthened MCH adsorption in the IEH mode. This work presents guidance for developing the novel catalytic reaction ways by IEH mode and designing corresponding high effective catalysts in hydrogen storage and other heterogeneous catalytic reaction processes. © 2024 Materials China. All rights reserved.