Achieving an enhancement in hydrolytic dehydrogenation of ammonia borane using nano-flower CoFeNiP alloy catalysts regulated from amorphous nanoparticle electroplating on Cu foams

The synthesis of abundant well-separated nanoparticles by electrodeposition is difficult since the electroplated nanoparticles tend to aggregate in their overlapping lateral diffusion zones. As a result, the facile electrodeposition method is rarely employed to prepare catalysts especially those for ammonia borane (AB) hydrolysis. Herein, well-separated amorphous CoFeNiP nanoparticles with a mean size less than 100 nm are obtained on Cu foams using galvanostatic electrodeposition. Remarkably, the glass-to-crystal structural transformation is activated in CoFeNiP after the first cycle of catalytic AB hydrolysis, accompanied by the changes in their morphology from monolithic nanoparticles to flower-like nano-ribbons with a characteristic size of ∼20 nm. The as-activated CoFeNiP alloy catalysts exhibit an enhancement in their performance of catalytic dehydrogenation of AB hydrolysis with a high turnover frequency of 12.5 min⁻¹ at 303 K and a low apparent activation energy of 23.4 kJ mol⁻¹, achieving ultrahigh durability after 5 cycles. The results demonstrate transition-metal phosphides could be used as practical noble-metal free alloy catalysts for hydrolytic dehydrogenation of AB with low cost, high performance and excellent recyclability.