Architecture control and electronic structure engineering over Ni-based nitride nanocomposite for boosting ammonia borane dehydrogenation

Abstract

Exploring cost-effective yet high-performance catalysts for dehydrogenation of ammonia borane (AB) is highly desirable for hydrogen economy. Transition metal nitrides (TMNs) have received huge attention in various energy storage/conversion systems, yet utilization for AB dehydrogenation is rarely studied. Herein we propose a green approach to Co doped Ni nitride nanoparticles anchored on reduced graphene oxide nanosheets (rGO/CoNi-N) from a bimetal-organic complex. The resultant rGO/CoNi-N presents outstanding catalytic AB dehydrogenation performance with a turnover frequency (TOF) value of 126.0 min−1 and an activation energy (Ea) of 32.8 kJ mol−1, rivalling state-of-the-art catalysts. Based on experimental and theoretical investigations, remarkable performance of rGO/CoNi-N can be attributed to full exposure of active sites and favorable mass transfer. Significantly, Co species incorporation in Ni-N can modulate electronic state with upshift of the d-band center, leading to promoted H2O adsorption and reduced energy barrier of the rate-determining step (H2O dissociation), thereby substantially boosting AB hydrolysis.