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

Abstract Catalytic splitting NH₃ to H₂ is one of the foundations for building a carbon‐free H₂ energy system but requires NH₃ splitting catalysts that are highly active and durable at low temperatures. Although various non‐noble catalysts have been designed, NH₃ 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 NH₃ splitting activity. Further, Ni single atoms supported on CeO₂ nanosheets (SA Ni/CeO₂) are synthesized by the sol–gel method, which exhibits a robust 3.544 mmol g⁻¹ min⁻¹ of H₂ yield speed of NH₃ 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 NH₃ splitting over SA Ni/CeO₂ shows a stable H₂ yield of 1.58 mmol g⁻¹ min⁻¹, 100 times the record value of advanced weak solar‐powered NH₃ splitting, demonstrating the potential for practical application in carbon‐free H₂ systems.