Pt/CrCeAlO催化剂对二氯甲烷的催化氧化性能

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，Cr_0.03Ce_0.05Al_0.95O₂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/Cr_0.03Ce_0.05Al₀.₉₅O₂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 performance of Pt/CrCeAlO catalysts for dichloromethane oxidation

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.