Ce-modified USY zeolite catalysts for catalytic oxidation of chlorinated VOCs:Effect of the location of CeO_(2) and its synergistic effect with USY zeolite  

作　　者：Xiaolin Guo Zhiming Li Ang Zhou Yijun Shi Yong Wang Renxian Zhou 

机构地区：[1]Institute of Catalysis,Zhejiang University,Hangzhou,310028,China [2]College of Materials and Chemistry,China Jiliang University,Hangzhou,310018,China

出　　处：《Journal of Rare Earths》2024年第11期2068-2077,I0003,共11页稀土学报（英文版）

基　　金：Project supported by the National Key Research and Development Program of China (2022YFB3504200)。

摘　　要：The catalytic behavior of a catalyst for chlorine-containing volatile organic compounds(CVOCs) oxidation largely depends on the synergistic interaction between the oxidizing and acidic sites.In the present work,two catalysts with different distributions of CeO_(2) on the inner and outer surfaces of 4.0Ce-USY-ex and 4.0Ce-USY-dp(USY zeolite) were prepared respectively by ion exchange and deposition methods,with a purpose of finding out how the location of the oxidation sites(CeO_(2)) influence its synergistic effect with the acidic sites of zeolite.The results show that 4.0Ce-USY-ex is much more active for catalytic degradation of 1,2-dichloroethane(DCE),while 4.0Ce-USY-dp catalyst exhibit higher catalytic degradation activity for other structured CVOCs(dichloromethane(DCM),trichloroethylene(TCE),chlorobenzene(CB)).CeO_(2) in 4.0Ce-USY-ex catalyst mainly disperses in the pore channels of USY zeolite,and there are many strong acid centers on the surface,which is conducive to the dechlorination conversion of CVOCs.However,CeO_(2) in 4.0Ce-USY-dp catalyst is mainly distributed on the outer surface of USY and has strong oxidation ability,which contributes to the deep oxidation of CVOCs.Moreover,the presence of a large number of strong acid centers on the catalyst surface of 4.0Ce-USY-ex catalysts leads to severe accumulation of surface carbon species and significantly decreases its stability towards DCE.However,a large number of active oxygen species on the surface of 4.0Ce-USY-dp and CeO_(2) catalysts are beneficial to the deep oxidation of DCE,reducing the formation of surface carbon and thus improving the stability of the catalyst.Thus,the influence of the location of the oxidation sites on its synergistic effect with the acidic sites was established in the present work,which could provide some new ideas for the rational design of CVOCs degradation catalyst with appropriate distribution of active sites.

关 键 词：CVOCs oxidation CeO_(2) USY LOCATION Synergistic effect Rare earths 

分 类 号：X701[环境科学与工程—环境工程] O643.36[理学—物理化学]