Controllable Synthesis of MoC and Mo2C to Boost Hydrogen Generation from Ammonia Borane Hydrolysis

Abstract

Ammonia borane has been proposed as a competitor to boost H2 evolution via the catalytic hydrolysis reaction at mild temperatures. A series of carbon nanotubes (CNTs)-supported Ni–MoxC catalysts with different MoxC crystalline phases are controllably synthesized using a facile two-step impregnation method followed by the thermal treatment. The catalyst structure and physicochemical properties are studied. The incorporation of MoxC is effective for enhancing the catalytic activity of Ni/CNTs, and the β-Mo2C is more beneficial to the ammonia borane hydrolysis than the α-MoC. 10Ni30Mo2C/CNTs exhibit superior catalytic activity with a turnover frequency (TOF) value of 71.0 min–1. Both experimental and theoretical results suggest that MoxC is responsible for H2O adsorption and activation while Ni is contributed to the ammonia borane molecule. Thus, this synergistic effect between MoxC and Ni enhances the catalytic hydrolysis of ammonia borane. This finding demonstrates the huge potential of MoxC for ammonia borane hydrolysis in hydrogen storage applications and provides a fangled sight for developing a unique class of low-cost catalytic system.