Pt/CrCeAlO催化剂对二氯甲烷的催化氧化性能  

Catalytic performance of Pt/CrCeAlO catalysts for dichloromethane oxidation

作　　者：陈淑霞[1] 陈秋艳[1] 李娜 罗孟飞[1] 鲁继青[1] 

机构地区：[1]浙江师范大学物理化学研究所先进催化材料省部共建教育部重点实验室,浙江金华321004

出　　处：《工业催化》2014年第1期64-71,共8页Industrial Catalysis

基　　金：国家自然科学基金(21173195)资助项目

摘　　要：催化氧化是消除挥发性有机废气的有效手段,而二氯甲烷是含氯有机废气的代表性化合物。采用沉淀法制备了不同CrO x含量的CrCeAlO催化剂,并用浸渍法制备了Pt/CrCeAlO催化剂,将其用于二氯甲烷催化氧化。结果表明,催化剂均表现出较好的活性,Cr0.03Ce0.05Al0.95O2催化剂在390℃时即可完全氧化二氯甲烷。而负载Pt后的催化剂活性明显提高,2.0Pt/Cr0.03Ce0.05Al0.95O2催化剂表现出最好的活性,在340℃条件下,转化率即达100%。采用XRD、SEM、TEM、H2-TPR和NH3-TPD对催化剂进行表征,表明催化剂的活性主要受其表面酸性和氧化还原性的影响,表面酸性位提供二氯甲烷化学吸附位,而催化剂表面氧化还原性则有利于反应中氧物种的活化。催化剂中添加Pt后,由于Pt、CeO2和CrO x物种间的相互作用而增强了催化剂的氧化还原性,从而进一步促进了反应活性的提高。Catalytic oxidation is an effective technique for removal of volatile organic compounds （VOCs）, and dichloromethane is a typical chlorinated organic compound （CVOCs）. A series of CrCeAIO catalysts with different CrOx contents was prepared by a co-precipitation method, and supported Pt/CrCeAIO catalysts were prepared by an impregnation method in this work. The properties of the catalysts for catalytic oxidation of dichloromethane （ CH2 Cl2 ） were investigated. The results showed that the catalysts possessed good activity and CH2C1z conversion of 100% was obtained at 390 ℃ over Cr0.03Ceo.osAlo.9502 catalyst. With the addition of Pt, the catalytic activity was further enhanced. 2.0Pt/Cr0.03 Ce0.05 Al0.95 02 Catalyst with 100% conversion of CH2Cl2 at 340 ℃ exhibited best catalytic activity. The catalysts were characterized by XRD,SEM,TEM, Hz-TPR and NH3-TPD. It was concluded that the catalytic behaviors of the catalysts were related to the surface acidity and redox property,as the former provided sites for CH2Cl2 chemisorp- tion, and the latter could activate oxygen species. The additiori of Pt further promoted the catalyst reduc- ibility via interactions among Pt, CeO2 and CrO2 species, which enhanced the catalytic performance of the catalysts.

关 键 词：催化化学 CrCeAlO PT催化剂 催化氧化 二氯甲烷 表面酸性 氧化还原性 

分 类 号：TQ426.6[化学工程] O643.36[理学—物理化学]