摘要
挥发性有机化合物(VOCs)是工业排放的典型污染物。苯作为其中一种,研究其催化分解,具有十分重要的意义~([1])。研究发现负载型贵金属催化剂表现出很高的催化活性。负载型钌催化剂因为其在较低温度下就有很高的氧化活性而受到很大关注~([2])。添加第二种金属对单金属催化剂进行修饰,可以大大改善催化剂的分散性、吸附性和活性,我们制备出核壳结构Ag-Ru双金属纳米颗粒,有效提高了催化活性。把Ag除去,得到空心结构的Ru,增大了催化剂的比表面积,与单金属钌相比,也显著提高了催化性能。金属与载体的相互作用在催化中有重要作用。研究发现,载体CeO_2在苯的催化氧化中有很高的活性和更好的稳定性。通过对钌催化剂进行修饰,水热法合成CeO_2,增强Ru和CeO_2的相互作用,发现负载在CeO_2上核壳结构的Ag-Ru催化剂,可以在190℃将苯完全催化分解为CO_2和H_2O。
Volatile organic compounds(VOCs) including benzene are typical contaminants emitted from industrial sources~([1]).Many studies have revealed the high catalytic activity of noble metals supported on different oxides.Supported ruthenium catalysts have received much interest,because of their high activity at low temperatures~([2]).The modification of the monometallic catalyst through adding a second metal can greatly improve the dispersion,adsorption and activity.Upon this,we prepared core-shell Ag-Ru nanoparticles with enhanced activity for benzene oxidation.By removing the Ag component from the core region,the resulting Ru particles with hollow interiors also have superior activity for benzene oxidation due to their high specific surface area.In addition,the substrates play an important role for the complete benzene oxidation using Ru-based catalysts.We found the Ru-based catalysts supported on CeO_2 substrates could effectively catalyze the complete conversion of benzene into CO_2 and H_2O at temperature of 190℃ or lower.
引文
[1]X.M.Zhang,Y.F.Huang,Z.Liu,K.P.Yan,J.Electrostat.76(2015)31–38.
[2]S.Hosokawa,Y.Fujinami,H.Kanai,J.Mol.Catal.A 240(2005)49–54.
