Coupling oxygen vacancy and hetero-phase junction for boosting catalytic activity of Pd toward hydrogen generation

Water dissociation is the rate-limiting step of many chemical reactions due to the high activation energy in the step of breaking O-H bond. Herein, an effective approach via coupling oxygen vacancy (VO) and hetero-phase junction to boost the ability of Pd catalysts toward water dissociation is determined. The Pd catalyst exhibits an outstanding catalytic activity in the hydrolysis of ammonia borane (AB) under alkaline additive-free condition at 298 K with a turnover frequency of 210 min−1. Theoretical simulation and characterization analyses reveal that both the appropriate interfacial charge states benefitting for adsorption caused by hetero-phase junction and the electron-rich Pd caused by VO enhance the intrinsic catalytic activity of Pd toward water dissociation in AB hydrolysis. This proof-of-concept research provides a valuable strategy for catalyst design, via coupling VO and hetero-phase junction to improve the reaction kinetics by boosting water dissociation in the field of catalytic energy conversion.