Bimetallic (Co/Ni) MOF-Derived CoNiP Hierarchically Porous Carbon Monolithic Aerogel for the Hydrolysis of Ammonia Borane

As a safe and efficient hydrogen storage material, ammonia borane (NH₃–BH₃, AB) shows great promise in the era of clean energy advocated by hydrogen. Thus, it is imperative to focus on the exploitation of high-performance heterogeneous catalytic systems for the effective utilization of hydrogen energy stored in AB. However, noble metal catalysts as high-efficiency systems suffer from high expenditure, and the traditional powder-based catalyst faces poor processability and recoverability. Herein, a bimetallic (Co/Ni) MOF-derived CoNiP/hierarchically porous carbon (HPC) monolithic aerogel was successfully prepared by the gelation–carbonization–phosphorization method and applied in the hydrolysis of AB. The ultrasmall transition bimetallic phosphide CoNiP nanoparticles were uniformly fabricated in the hierarchically porous aerogel after pyrolysis. Benefiting from the rapid mass transfer and high exposure of well-defined CoNiP-active species within the hierarchical aerogel support, the Co_0.3Ni_0.7P/HPC aerogel performed high hydrogen evolution activity and exhibited fast hydrogen generation rate with a completion time of 2 min under mild conditions. The theoretical calculations reveal the key effects of the adsorption energies between AB and water on CoNiP-active sites in the Co_0.3Ni_0.7P/HPC aerogel. Furthermore, the Co_0.3Ni_0.7P/HPC monolithic aerogel catalyst can be effortlessly separated and recycled at least 10 times without a remarkable loss of activity. The controllable design of P-doped bimetallic species in the porous aerogel herein should serve as the foundation for the preparation of practical functional monolithic applied catalysts for the hydrolysis of AB.