Functional Group Regulated Ni/TiCT (T = F, -OH) Holding Bimolecular Activation Tunnel for Enhanced Ammonia Borane Hydrolysis.

Developing economical and efficient catalyst for hydrogen generation from ammonia borane (AB) hydrolysis is still a huge challenge. As an alternative strategy, the functional group regulation of metal nanoparticles (NPs)-based catalysts is believed to be capable of improving the catalytic activity. Herein, a series of Ni/TiCT-Y (T = F, -OH; Y denotes etching time (d)) catalysts are synthesized and show remarkably enhanced catalytic activity on the hydrolysis of AB in contrast to the corresponding without regulating. The optimized Ni/TiCT-4 with a turnover frequency (TOF) value of 161.0 min exhibits the highest catalytic activity among the non-noble monometallic-based catalyst. Experimental results and theory calculations demonstrate that the excellent catalytic activity benefits from the bimolecular activation channels formed by Ni NPs and TiCT-Y. HO and AB molecules are activated simultaneously in the bimolecular activation tunnel. Bimolecular activation reduces the activation energy of AB hydrolysis, and hydrogen generation rate is promoted. This article provides a new approach to design effective catalysts and further supports the bimolecular activation model for the hydrolysis of AB.