Defective Ehanced Subnano-Rh Catalyst Supported on an Ni@Ni-N-C Substrate for Highly Efficient Hydrolytic Dehydrogenation of Ammonia Borane

Ammonia borane (NH3BH3, referred to as AB) hydrolytic dehydrogenation is regarded as a feasible strategy for hydrogen production owing to its high hydrogen content, pollution-free nature, and high stability. Metal nitrogen-doped carbon materials (M-N-C) are considered as an ideal candidate support of catalysts with AB hydrolytic dehydrogenation due to the advantages of low cost, large specific surface area, rich defective site, and good chemical stability. In this work, tubular Ni@Ni-N-C was successfully synthesized by high-temperature pyrolysis, and then, Rh nanoparticles were decorated on the support Ni@Ni-N-C by impregnation and reduction to prepare a series of Rh/Ni@Ni-N-C. The best catalytic performance of catalysts is obtained using Ni@Ni-N-C with an Rh loading of 0.74 wt %, showing a turnover frequency as high as 782.18 min–1 and an apparent activation energy (Ea) as low as 25.86 kJ mol–1, which could be attributed to the strong interaction between Rh and the defective site of the support.