Polar O–Co–P Surface for Bimolecular Activation in Catalytic Hydrogen Generation

Abstract

Boron hydrides release an abundant amount of hydrogen in the presence of a suitable catalyst. Accelerating bimolecular activation kinetics is the key to designing cost-effective catalysts for borohydride hydrolysis. In this study, the bimolecular activation of a polar O–Co–P site demonstrated superior hydrogen-generation kinetics (turnover frequency, TOF = 37 min−1, 298 K) and low activation energy (41.0 kJ mol−1) close to that of noble-metal-based catalysts. Through a combination of experiments and theoretical calculations, it was revealed that the activated dangling oxygen atom in the Co–O precursor effectively replaced via surface-phosphorization because of strong electronic interactions between the dangling oxygen and P atoms. This substitution modulated the local coordination environment and electronegativity around the surface Co sites and formed a new polar O–Co–P active site for optimizing the activation kinetics of ammonia borane and water. This strategy based on bimolecular activation may create new avenues in the field of catalysis.