Thermocatalytic Hydrogen Production from Water at Boiling Condition

Thermochemical water-splitting cycles are technically feasible for hydrogen production from water. However, the ultrahigh operation temperature and low efficiency seriously restrict their practical application. Herein, one-step and one-pot thermocatalytic water-splitting process is reported at water boiling condition catalyzed by single atomic Pt on defective In₂O₃. Water splitting into hydrogen is verified by D₂O isotopic experiment, with an optimized hydrogen production rate of 36.4 mmol·h^-1·g^-1 as calculated on Pt active sites. It is revealed that three-centered Pt₁In₂ surrounding oxygen vacancy as catalytic ensembles promote the dissociation of the adsorbed water into H, which transfers to singlet atomic Pt sites for H₂ production. Remaining OH groups on adjacent In sites from Pt₁In₂ ensembles undergoes O─O bonding, hyperoxide formation and diminishing via triethylamine oxidation, water re-adsorption for completing the catalytic cycle. Current work represents an isothermal and continuous thermocatalytic water splitting under mild condition, which can re-awaken the research interest to produce H₂ from water using low-grade heat and competes with photocatalytic, electrolytic, and photoelectric reactions.