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

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. The Ni single atoms show a H2 yield of 3.544 mmol g−1 min−1 of NH3 splitting at 300 °C and H2 production efficiency of 1.58 mmol g−1 min−1 solar heating NH3 splitting under one solar irradiance, 100 times higher than the record values of advanced weak solar driven NH3 splitting.