旋转CVD技术及其在陶瓷粉体担载纳米粒子催化剂制备中的应用

担载型纳米粒子催化材料通常是指将金属或金属氧化物活性相以纳米粒子的形式分散到惰性担载陶瓷粉体表面而形成的复合粉体材料。提高纳米粒子催化材料的分散均匀性是获得高催化性能的关键。传统的溶胶-凝胶法、浸润法等处理步骤冗长,易导致纳米粒子的团聚长大,降低催化效果。流化床化学气相沉积方法则比较适合处理粒径在40mm~500mm的担载粉体。本文着重介绍了粉体旋转化学气相沉积技术的原理,并以镍纳米粒子为例阐述了这种技术的相关应用。采用旋转化学气相沉积技术,在六方氮化硼(hBN)、立方氮化硼(cBN)、氧化铝(Al_2O_3)、氧化硅(SiO_2)等粉体表面沉积(包覆)了镍纳米粒子,显示出了优越的催化性能。本文同时分析了旋转化学气相沉积技术存在的问题及未来的研究前景。

Advances in Rotary Chemical Vapor Deposition and Its Applications in Fabrication of Ceramic-Supported Nanoparticle Catalysts

Supported catalysts are usually composite powders composed of catalytic nanoparticles dispersed on inert support powders. The uniform distribution of nanoparticles is a key factor to get the high catalytic performance. Traditional methods, such as sol-gel and impregnation, would induce the agglomeration of nanoparticles with a long treating procedure. Whereas the fluidized bed chemical vapor deposition (FBCVD) is applicable for surface modification of powders 40 mm ~ 500 mm in diameter. This review introduces the technical principles of the rotary CVD (RCVD) method and its successful applications with Ni as an example catalyst. The Ni nanoparticles were successfully dispersed on ceramic powders such as hBN, cBN, Al2O3 and SiO2, and exhibited superior catalytic performance. The challenges were also presented for further applications.