硅溶胶负载非晶态NiB纳米团簇的制备与催化加氢性能

Preparation of Silica Sol-Supported NiB Nanoclusters and Their Catalytic Hydrogenation Performance

以硅溶胶为载体,通过化学还原法制备了具有超小尺寸的非晶态NiB催化剂.采用高倍透射电镜、选区电子衍射和能量色散谱对样品的形貌和结构进行了表征.结果表明,以硅溶胶为载体负载的非晶态NiB催化剂,其活性组分的粒径在1～2nm,并且活性组分Ni均匀地分布于硅溶胶载体上.与传统的Raney Ni催化剂相比,NiB/硅溶胶表现出更为优异的催化加氢性能并极大地提高了氢化效率.催化剂的优良活性可归因于载体硅溶胶的大表面积及其硅烷醇对活性组分的锚定功能,这使活性组分Ni以超小尺寸均匀地分散于载体上,从而使纳米粒子的表面效应得到充分发挥.

Amorphous NiB supported on silica sol with extremely small size was synthesized by chemical reduction. The morphology and structure of the samples were characterized by high resolution transmission electron microscopy, select area electron diffraction, and energy dispersive spectroscopy. The grain size of amorphous Ni was between 1 and 2 nm, and the distribution of the components was regular. NiB/silica sol exhibited a higher hydrogenation activity than commercial Raney Ni. This was ascribed to the high surface area of the silica sol and available silanol groups to anchor the active catalyst. The active Ni was highly dispersed on the support, and the surface effects of the small nanoparticles played a key role in hydrogenation.