Highly efficient CoNiP nanoboxes on graphene oxide for the hydrolysis of ammonia borane

Efficient and low-cost catalysts for the hydrolysis of Ammonia borane (AB) are highly required for the hydrogen economy. Here we report a highly efficient CoNiP nanobox on graphene oxide (GO) for the hydrolysis of AB. By modulating the electronic structure of Co in the catalyst with small amount of doped Ni (1.7 wt%), the hydrolysis activity can be significantly enhanced up to 4 times of the original activity. The CoNiP/GO catalyst can thus achieve a remarkable TOF value of 134.6 (H-2) mol/((Cat-metal)mol.min), which is one of the best values ever reported for noble metal-free catalysts. The catalyst also shows a low activation energy of 44.12 kJ/mol and a good durability of 84.6% after five cycles. Synchrotron radiation based X-ray absorption spectroscopy reveals that the high performance can be mainly attributed to the slightly modulated chemical state of Co, which is suitable for the hydrolysis reaction. The favorable nanobox morphology and GO support also contribute to the high performance.