Nickel single atoms/cerium oxide hybrid for hydrogen production via solar-heating catalytic dehydrogenation of methyl Cyclohexane

Methylcyclohexane (MCH)-toluene-hydrogen cycle can realize the recycling of matter and energy, owning a wide foreground in industrial application. The MCH dehydrogenation process is highly endothermic, and a heating temperature is needed to stimulate this reaction. The combination of thermal catalytic reactor and solar-to-heat system can realize solar-heating catalytic MCH dehydrogenation reaction. Whereas, such a highly desirable advanced system has not yet been reported. In this study, a hybrid of single-atom nickel anchored on cerium oxide nanosheets (Ni SA/CeO2 NS) has been constructed successfully. The hybrid exhibits remarkable thermal catalytic activity in MCH dehydrogenation, owning an H2 generation rate of 2756 mmol g-1 h-1 at 400 degrees C. The stepwise MCH dehydrogenation mechanism on the hybrid is investigated via density functional theory calcu-lations. Moreover, we have developed a novel type of solar-to-heat device based on Ti2O3 thin film/Cu. Based on this device and the Ni SA/CeO2 NS hybrid, a solar-heating catalysis mode has been developed, with the H2 generation rates of 404 and 2604 mmol g-1 h-1 from MCH dehydrogenation under 1 and 2 kW m- 2, respectively. This strategy provides the possibility to realize scalable MCH dehydrogenation under solar irradiation without secondary energy input.

Automated summary

The MCH-toluene-hydrogen cycle has potential in industrial applications for recycling matter and energy. A hybrid catalyst of single-atom nickel anchored on cerium oxide nanosheets has been successfully constructed, demonstrating excellent thermal catalytic activity in MCH dehydrogenation. By combining this catalyst with a solar-to-heat device, a solar-heating catalysis mode has been developed for scalable MCH dehydrogenation under solar irradiation.