Cobalt nanoparticles embedded in porous N-doped carbon as long-life catalysts for hydrolysis of ammonia borane

Abstract

Cobalt-based materials are promising catalysts for hydrolysis of ammonia borane. However, the stability of such catalysts is still a challenge for their application. We here report the one-step synthesis of Co nanoparticles embedded in porous N-doped carbon (denoted as Co@N-C) and their enhanced catalytic stability for hydrolysis of ammonia borane. The Co@N-C catalysts are fabricated through one-step thermolysis of Co(salen) at selected temperatures (600–800 °C) under an Ar atmosphere. It is found that among the catalysts in this study, the Co@N-C nanocomposite obtained at 700 °C (Co@N-C-700) shows superior catalytic activity and high sustainability. The turnover frequency (TOF) and activation energy of Co@N-C-700 for the hydrolysis of ammonia borane are 5.6 mol_H2 mol_Co⁻¹ min⁻¹ and 31.0 kJ mol⁻¹, respectively. In particular, this catalyst retains 97.2% of its initial catalytic activity after 10 cycles. The remakable catalytic activity and durability of Co@N-C-700 are attributed to the high dispersion of the Co nanoparticles in the porous N-doped carbon. This would provide insights into the enhancement of the cycling utilization of the Co@N-C-700 nanocomposite for catalytic hydrolysis of ammonia borane.