Hierarchical porous cobalt/carbon hybrid anchored Ru-catalyzed ammonia-borane hydrolysis for efficient H2 release

[Display omitted] •Hierarchical hybrid of Co NPs and NC was synthesized by NaCl-template method.•The obtained Co-NC was applied to deposit Ru NPs via an in-situ reduction method.•The optimal Ru@Co-NC possessed TOFs of 568/1131 min−1 in aqueous/basic solutions.•Rich surface sites, fast mass/electron transfer and electronic synergy enhanced RDS.•This catalyst was magnetically recoverable and could be reused for five times. Development of hierarchical architecture composed of heteroatom-doped porous carbon and earth-abundant transition metal for anchoring of noble metal nanoparticles (NPs) is essential but challengeable to improve catalytic performance for hydrogen production from ammonia-borane (AB) hydrolysis. In this study, we report the utilization of hierarchical porous nitrogen-doped carbon nanosheets encapsulated Co (Co-NC) synthesized by sodium chloride-template method for anchoring of Ru NPs toward hydrogen production from AB hydrolysis. The achieved Ru@Co-NC with an optimal Ru loading of 1.0 wt% delivers the highest catalytic activities with turnover frequencies of 568/1131 min−1 under aqueous/alkaline conditions at 25 ℃. The high performance for AB hydrolysis can be ascribed to the abundance of surface sites, fast mass/electron transfer and the electronic metal-support interaction between ultrafine Ru NPs and Co-NC, which facilitate the oxidative cleavage of the OH bonds in attacked H2O molecules (rate-determining step). Besides, this catalyst can be easily isolated by an external magnet and exhibits relatively good reusability with high maintained activity after five cycles. This work emphasizes the utilization of magnetically hierarchical architecture as support for noble metal NPs toward catalytic hydrogen generation.