稀土元素镧与铈对VOx／TiO2催化降解氯苯性能的影响  

Effect of Lanthanon La and Ce Addition on VOx/TiO2 Catalyst for the Catalytic Combustion of Chlorobenzene

作　　者：秦昆[1] 刘善堂[1] 

机构地区：[1]武汉工程大学化工与制药学院,绿色化工过程教育部重点实验室,湖北武汉430074

出　　处：《纳米科技》2013年第3期12-17,共6页

基　　金：湖北省自然科学基金重点项目（2011CDA049）,湖北省教育厅科学技术研究重大项目（Z20091502）,武汉市学科带头人计划（200951830551）

摘　　要：采用等体积浸渍法分别制备了不同稀土元素@阑或铈）添加量的VOx／TiO催化剂，通过XRD、EDS和TPR对样品进行表征，考察了它们催化燃烧氯苯的活性，结果表明，不同镧或铈添加量的催化剂样品仍保持TiO2税钛矿晶相。当LaOx与VOx的摩尔比为1：5时，会出现镧钒氧物种或镧钛氧物种的晶相；当CeOx与VOx的摩尔比为1．5时，会出现CeOx方铈矿萤石结构的晶相；镧和铈的添加会提高活性物种VOx在催化剂表面的含量和分数}生。当CeOx与VOx的摩尔比为1：13．7时，活性组分VOx绝大部分分布在载体表面；镧对于催化剂的氧化性能没有影响，而铈能提高催化剂的氧化性；适量镧或铈的添加对于VO／TiO2催化剂催化降解氯苯有促进作用。锏的添加对于催化剂催化活性的促进作用与催化剂表面活性物VOx含量有关，而铈的添加对催化剂催化活性的提高作用除此原因外，还与催化剂氧化洼的提高有关。A series of VO/FiO2 catalysts with different lanthanon（La or Ce） loadings were prepared by incipient-wetness impregna- tion method （[WI）, respectively. The obtained catalysts were characterized by XRD, EDS and TPR and their catalytic oxidation per- formance for ehlorobenzene was investigated. The result showed that TiO2 anatase phase was not influenced by the catalyst samples with different La or Ce loadings. When the molarratio of LaO;VOxis 12, the crystalline of mixed oxide species containing lanthanuro, vanadium or containing lanthanum, titanium appeared and when the molar ratio of CeO,;VOx is 1：5, the crystalline of CeO2 eerianite fluorite appeared. The addition of La or Ce into the VOx/TiO2 catalyst enhanced the content of active component VOx on the catalyst surface,namely, it could promote the dispersion of the active species VOx on the surface of the catalyst. And when the molar ratio of CeO;VOxis 1：13.7, most of the active species VOx dispersed on the surface of the support. The addition of La had no effect on the oxi- dation ability of the catalyst while the addition of Ce improved the oxidation ability of the catalyst. The catalytic activity evaluation of the catalysts indicated that the addition of a certain amount of La or Ce to the V O/TiO2 based catalyst could improve the catalytic ac- tivity in the catalytic combustion ofchlorobenzene. The performance improvement of the catalyst doped with La is associated with the increase of the content of surface active component VOx, while the promotion effect in the catalytic activity for the Ce doped catalyst is correlated with the improvement of the oxidation ability for the catalyst in addition to this reason.

关 键 词：VLA Ti催化剂 VCe Ti催化剂 催化性能 氯苯 

分 类 号：O643.3[理学—物理化学]