Cobalt nickel nanoparticles encapsulated within hexagonal boron nitride as stable, catalytic dehydrogenation nanoreactor

Herein, Non-noble bimetallic CoNi nanoparticles encapsulated within h-BN (CoNi@h-BN) is successfully synthesized via annealing freshly prepared metal ammine boride complexes [Co0.5Ni0.5(NH3)(6)]Cl-3)/NH4BO2 and KBH4 under flowing nitrogen gas at 900 degrees C for 2 h. The result showed that CoNi nanoparticles with general size of 17 nm completely encapsulated by h-BN shells, and the h-BN shells on the CoNi nanoparticles are 10-20 layers. The obtained CoNi@h-BN demonstrates high sustainability, good stability and outstanding catalytic activity on hydrolysis of ammonia borane under air atmosphere and ambient temperature, compared with their monometallic counterparts and former reported catalysts. Specifically, the activation energy (E-a) of CoNi@h-BN for hydrolysis of ammonia borane is determined to be 28 kJ mol(-1). The improved performance is due to the modified chemical properties and electronic structure of CoNi NPs after encapsulation, and the strong mutual coupling effect between the basic sites of h-BN and ammonia borane. Furthermore, the magnetic catalysts can be easily recycled for cyclic utilization, and remain the high catalytic activity even recycled 5 times. Possible synthesis and catalytic mechanism are explored, and the excellent property of CoNi@h-BN and novel synthesis strategy are expected to profit catalysts in field of electrochemical sensors, high thermal conductive adhesive materials and fuel cells. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.