Selective H₂ Production upon NH₃BH₃ Hydrolysis over a Magnetic Cu/Ni-CMS Catalyst

H₂ production from chemical hydrogen storage materials, such as ammonia borane, has attracted widespread attention as an innovative and promising alternative to traditional hydrogen storage approaches, offering notable advantages including high storage density and enhanced safety. Herein, a series of non-noble metal nanocomposites as high-powered nanocatalysts were fabricated via fixation of transition metal nanoparticles (Fe, Co, Ni, and Cu) onto Ni-enriched carbon microspheres (Ni-CMSs) for selective H₂ production upon NH₃BH₃ hydrolysis. The optimal Cu/Ni-CMS nanocomposite exhibited the highest catalytic efficiency in H₂ production upon NH₃BH₃ hydrolysis, with a remarkable rate of 1449.74 mL(H₂). g_cat^-1 min^-1 at 30 °C. Various physical characterizations confirmed that Cu nanoparticles were successfully immobilized onto Ni-CMS; The as-prepared Cu/Ni-CMS was composed of homogeneously distributed Cu, Ni, C, N, and O elements throughout the hollow structure of Ni-CMS. Attractively, the magnetic Cu/Ni-CMS can be rapidly separated and reused over 10 catalytic cycles using an external magnet during NH₃BH₃ hydrolysis for H₂ production, with negligible activity loss. This work could provide a facile and simple route for the synthesis of non-noble metal catalysts for H₂ evolution.