Bimetallic (Co/Ni)\nMOF-Derived CoNiP Hierarchically\nPorous Carbon Monolithic Aerogel for the Hydrolysis of Ammonia Borane

As a safe and efficient hydrogen storage material, ammonia\nborane\n(NH<sub>3</sub>–BH<sub>3</sub>, AB) shows great promise in\nthe era of clean energy advocated by hydrogen. Thus, it is imperative\nto focus on the exploitation of high-performance heterogeneous catalytic\nsystems for the effective utilization of hydrogen energy stored in\nAB. However, noble metal catalysts as high-efficiency systems suffer\nfrom high expenditure, and the traditional powder-based catalyst faces\npoor processability and recoverability. Herein, a bimetallic (Co/Ni)\nMOF-derived CoNiP/hierarchically porous carbon (HPC) monolithic aerogel\nwas successfully prepared by the gelation–carbonization–phosphorization\nmethod and applied in the hydrolysis of AB. The ultrasmall transition\nbimetallic phosphide CoNiP nanoparticles were uniformly fabricated\nin the hierarchically porous aerogel after pyrolysis. Benefiting from\nthe rapid mass transfer and high exposure of well-defined CoNiP-active\nspecies within the hierarchical aerogel support, the Co<sub>0.3</sub>Ni<sub>0.7</sub>P/HPC aerogel performed high hydrogen evolution activity\nand exhibited fast hydrogen generation rate with a completion time\nof 2 min under mild conditions. The theoretical calculations reveal\nthe key effects of the adsorption energies between AB and water on\nCoNiP-active sites in the Co<sub>0.3</sub>Ni<sub>0.7</sub>P/HPC aerogel.\nFurthermore, the Co<sub>0.3</sub>Ni<sub>0.7</sub>P/HPC monolithic\naerogel catalyst can be effortlessly separated and recycled at least\n10 times without a remarkable loss of activity. The controllable design\nof <i>P</i>-doped bimetallic species in the porous aerogel\nherein should serve as the foundation for the preparation of practical\nfunctional monolithic applied catalysts for the hydrolysis of AB.