Cr-Ce氧化物改性H-MOR分子筛催化氧化降解三氯乙烯的研究  

Studies on Cr-Ce / H-MOR Catalysts for the Oxidative Degradation of Trichloroethylene

作　　者：钱金泽[1] 李森[1] 罗勇[2,1,3] 陈明良[1] 

机构地区：[1]上海化工研究院,上海200062 [2]聚烯烃催化技术与高性能材料国家重点实验室,上海200062 [3]上海市聚烯烃催化技术重点实验室,上海200062

出　　处：《精细化工》2016年第7期779-786,共8页Fine Chemicals

基　　金：上海市浦江人才计划(14PJ1432600)~~

摘　　要：采用等体积浸渍法制备了一系列不同n（Cr）∶n（Ce）的Cr-Ce/H-MOR催化剂。利用XRD、H2-TPR和NH3-TPD等对催化剂结构和性质进行表征。结果表明：催化剂表面存在铬铈氧化物;催化剂在100~600℃范围内出现耗氢峰和NH3脱附峰,说明具有一定的氧化性和酸性。利用固定床连续反应器装置,在15 000 h^-1的空速下,评价了所制催化剂对氧化降解三氯乙烯（TCE）的催化活性。结果表明,n（Cr）∶n（Ce）=1∶1时的催化剂（1Cr-1Ce/H-MOR）具有最优的催化活性,在279.4℃时对三氯乙烯转化率达90%。稳定性实验表明：反应400 min后,该催化剂上TCE转化率下降了9.2%。采用XRD、TG和XPS对反应前后的1Cr-1Ce/H-MOR催化剂进行表征,结果表明：催化剂结构没有发生改变,表面也无明显积炭现象;其催化活性下降可能是由n（Cr^6＋）和n（Ce^3＋）比例下降及催化剂表面吸附Cl物种引起的。Series of Cr-Ce / H-MOR catalysts with different molar ratio of Cr to Ce were prepared by incipient wetness impregnation method. The obtained catalysts were characterized by XRD,H2-TPR and NH3-TPD. The results indicated that the chromium oxides and cerium oxides were introduced on the surface of H-MOR. Hydrogen consumption peak and NH3 desorption in the range of 100 ~ 600 ℃indicated that the synthesized catalysts possessed a certain oxidizability and acidity. The catalytic activity of the catalysts for oxidative degradation of trichloroethylene（ TCE） was investigated in a continuous fixed bed reactor with 15 000 h^- 1GHSV. The results showed that the 1Cr-1Ce / H-MOR catalyst with molar ratio of Cr to Ce of 1 ∶ 1 had the best catalytic activity for TCE. The conversion of TCE reached up to 90% at 279. 4 ℃. Stability tests showed that the catalytic activity of the 1Cr-1Ce /H-MOR catalyst decreased by 9. 2%,after the reaction was carried out for 400 min. XRD,TG and XPS were used to characterize the 1Cr-1Ce / H-MOR catalyst,before and after reaction. The results displayed that the catalyst structure had no change and there was no carbon deposition on the catalyst surface.The decrease of the proportion of Cr^6 ＋and Ce^3 ＋and the adsorption of Cl species on the catalyst surfacemight result in the decrease of the activity of the catalyst.

关 键 词：三氯乙烯 催化氧化 H-MOR分子筛 铬铈氧化物 催化技术 

分 类 号：TQ13[化学工程—无机化工] X13[环境科学与工程—环境科学]