Low Temperature Thermal and Solar Heating Carbon‐Free Hydrogen Production from Ammonia Using Nickel Single Atom Catalysts

Abstract Catalytic splitting NH 3 to H 2 is one of the foundations for building a carbon‐free H 2 energy system but requires NH 3 splitting catalysts that are highly active and durable at low temperatures. Although various non‐noble catalysts have been designed, NH 3 splitting still operates at relatively high temperatures (600–850 °C). Herein, theoretical calculations predict that the Ni single atoms can change the bonding mode of NiN from covalent bond to ionic bond to boost the NH 3 splitting activity. Further, Ni single atoms supported on CeO 2 nanosheets (SA Ni/CeO 2 ) are synthesized by the sol–gel method, which exhibits a robust 3.544 mmol g −1 min −1 of H 2 yield speed of NH 3 splitting at 300 °C, superior to all non‐noble catalysts and most of the noble catalysts. Combing with the homemade solar heating device, the one sun‐driven NH 3 splitting over SA Ni/CeO 2 shows a stable H 2 yield of 1.58 mmol g −1 min −1 , 100 times the record value of advanced weak solar‐powered NH 3 splitting, demonstrating the potential for practical application in carbon‐free H 2 systems.