Synergistic performance between oxidizability and acidity/texture properties for 1,2-dichloroethane oxidation over (Ce,Cr)xO2/zeolite catalysts

(Ce,Cr)xO2/zeolite catalysts with Ce/Cr molar ratio of 4:1 and equivalent mass of (Ce,Cr)xO2 and zeolite are prepared by a deposition–precipitation method, and tested for deep catalytic oxidation of 1,2-dichloroethane. Based on the values of T90% (temperature at which 90% conversion is obtained), the catalytic activity decreases in the order of (Ce,Cr)xO2/HZSM-5 (230 °C)>(Ce,Cr)xO2/H-BETA (243 °C)>(Ce,Cr)xO2/USY (247 °C)>(Ce,Cr)xO2/H-MOR (253 °C), which is improved obviously than (Ce,Cr)xO2 and parent zeolites, indicting the existence of synergistic effect between (Ce,Cr)xO2 and zeolites. This synergy is resulted from that the strong acid sites of the zeolites firstly promotes 1,2-dichloroethane adsorption and dehydrochlorination, while the strong oxidative sites of (Ce,Cr)xO2 is in favor of the deep oxidation of the reactants, the intermediates and byproducts as well as the reduction of coke and Cl accumulation on the catalyst surface. Especially, (Ce,Cr)xO2/HZSM-5 represents the best catalytic activity and durability, which is also related to its special intersectional pore structure. Moreover, though the presence of benzene or water decreases the catalytic activity in the initial stage because of the competitive adsorption on active sites, (Ce,Cr)xO2/HZSM-5 represents good durability during the prolonged reaction time.