Ni nanoparticles supported on carbon as efficient catalysts for the hydrolysis of ammonia borane
Ni nanoparticles, ammonia borane, catalytic hydrolysis, hydrogen generation
We report on the preparation of three kinds of Ni nanoparticles supported on carbon (Ni/C) and their application in the catalytic hydrolysis of ammonia borane (AB). Three Ni/C catalysts were prepared from a Ni metal–organic framework (Ni-MOF) precursor by reduction with KBH4, calcination at 700 °C under Ar, and a combination of calcination and reduction, the products being denoted as Ni/C-1, Ni/C-2, and Ni/C-3, respectively. The structure, morphology, specific surface area, and element valence were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption–desorption measurements, and X-ray photoelectron spectra (XPS). The results demonstrate that Ni/C-1 is composed of amorphous Ni particles agglomerated on carbon, Ni/C-2 is characteristic of crystalline Ni nanoparticles (about 10 nm in size) supported on carbon with Ni oxidized on the surface, while the surface of the Ni particles in Ni/C-3 is less oxidized. The specific surface areas of Ni-MOF, Ni/C-1, Ni/C-2, and Ni/C-3 are 1239, 33, 470, and 451 m2·g–1, respectively. The catalytic hydrolysis of AB with Ni/C-3 shows a hydrogen generation rate of 834 mL·min–1·g–1 at room temperature and an activation energy of 31.6 kJ/mol. Ni/C-3 shows higher catalytic activity than other materials, which can be attributed to its larger surface area of crystalline Ni. This study offers a promising way to replace noble metal by Ni nanoparticles for AB hydrolysis under ambient conditions.
Tsinghua University Press
Limin Zhou,Tianran Zhang,Zhanliang Tao,Jun Chen, Ni nanoparticles supported on carbon as efficient catalysts for the hydrolysis of ammonia borane. NanoRes.2014, 7(5): 774–781