Study on the catalytic mechanism of core-shell structure CoCu@BN promoting the hydrolytic dehydrogenation of ammonia borane

Abstract

Ammonia borane (NH₃BH₃, AB) as one of the complex hydrides shows great potential for hydrogen storage. Nevertheless, the lack of efficient catalysts limits the hydrogen release rate. Herein, we reported a heterostructure catalyst consisting of Co and Cu nanoparticles with a boron nitride cladding (defined as CoCu@BN). Remarkably, on the basis of BN shell formation, CoCu particles are confined with a stable nanoscale of around 10 nm. As a result, the optimal Co₀₈Cu_0.2@BN catalyst demonstrates excellent catalytic performance, achieving a high TOF of 28.8 mol_H2 mol_metal⁻¹ min⁻¹, which is far superior to the Co@BN and Cu@BN. The catalytic mechanism has been verified, demonstrating that the combined compositional and structural characteristics of Co_0·8Cu_0.2@BN synergistically induce robust electron transfer. This phenomenon accelerates the cleavage of H₂O molecules (the rate-determining step), thereby enhancing the catalytic hydrolysis of AB. The findings presented in this study offer a precise and controllable strategy for designing non-noble metal catalysts aimed at hydrogen production.