Zhu Qiu-Feng, Gao Jin, Chen Jian-Feng, Wen Li-Xiong
Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, PR China.
J Nanosci Nanotechnol. 2010 Sep;10(9):5641-7. doi: 10.1166/jnn.2010.2472.
A novel egg-shell Pd/PHSNs nano-catalyst was prepared by a wet impregnation method using self-synthesized porous hollow silica nanoparticles (PHSNs) as support and applied in selective hydrogenation of acetylene to remove acetylene from the ethylene feed. By controlling the preparing conditions and calcining temperature, the active metal particles were loaded evenly on the support with a size about 5 nm. Compared with conventional catalysts prepared with solid silica nanoparticles, solid Al2O3 millispheres and a commercial catalyst, the Pd/PHSNs catalyst showed higher acetylene conversion rates at same reaction temperatures, and the porous hollow nano structure of PHSNs allowed smoother diffusion of ethylene molecules within the catalyst matrix so that ethylene could migrate away from the active sites in time to avoid turning into ethane, which resulted in superior ethylene selectivity at high acetylene conversion rates.
采用湿浸渍法，以自合成的多孔空心二氧化硅纳米颗粒（PHSNs）为载体，制备了一种新型蛋壳型Pd/PHSNs纳米催化剂，并将其应用于乙炔的选择性加氢反应，以从乙烯进料中脱除乙炔。通过控制制备条件和煅烧温度，活性金属颗粒均匀负载在载体上，粒径约为5nm。与用固体二氧化硅纳米颗粒、固体Al2O3微球和商业催化剂制备的传统催化剂相比，Pd/PHSNs催化剂在相同反应温度下表现出更高的乙炔转化率，并且PHSNs的多孔空心纳米结构使乙烯分子在催化剂基质内的扩散更顺畅，从而使乙烯能够及时从活性位点迁移开，避免转化为乙烷，这导致在高乙炔转化率下具有优异的乙烯选择性。
