Synthesis of neodymium modified CeO_2-ZrO_2-Al_2O_3 support materials and their application in Pd-only three-way catalysts  

作　　者：彭娜 周菊发 陈山虎 罗秀超 陈耀强 龚茂初 

机构地区：[1]Key Laboratory of Green Chemistry&Technology of the Ministry of Education,Sichuan University

出　　处：《Journal of Rare Earths》2012年第4期342-349,共8页稀土学报（英文版）

基　　金：Project supported by National Natural Science Foundation of China (20773090, 20803049);the Specialized Research Fund for the Doctoral Program of Higher Education (20070610026, 200806100009)

摘　　要：Ce-Zr-Al-Nd2O3 （CZAN） support materials were prepared by co-precipitation and impregnation methods, respectively. They were characterized by X-ray diffTaction （XRD）, low temperature nitrogen adsorption-desorption, oxygen pulsing technique, H2-temperamre programmed reduction （H2-TPR） and X-ray photoelectron spectroscopy （XPS）. The Pd-only three-way catalysts （Pd-TWC） supported on these materials were prepared by incipient wetness method and studied by activity tests. The results demonstrated that the CZAN supports obtained by the two methods showed better structural, textural and redox properties than the CZA without Nd2O3, and the addition of Nd203 improved the catalytic activity of TWC. Especially, the CZAN-i support prepared by impregnation method had better thermal stability and redox property. Meanwhile, the Pd/CZAN-i catalyst exhibited the best catalytic performance. XPS measurements indicated that the Nd-modified samples possessed more Ce3＋ and oxygen vacancies on the surface of samples, which led to a better redox property. The excellent redox property of support materials helped to improve the catalytic activity of TWC.Ce-Zr-Al-Nd2O3 （CZAN） support materials were prepared by co-precipitation and impregnation methods, respectively. They were characterized by X-ray diffTaction （XRD）, low temperature nitrogen adsorption-desorption, oxygen pulsing technique, H2-temperamre programmed reduction （H2-TPR） and X-ray photoelectron spectroscopy （XPS）. The Pd-only three-way catalysts （Pd-TWC） supported on these materials were prepared by incipient wetness method and studied by activity tests. The results demonstrated that the CZAN supports obtained by the two methods showed better structural, textural and redox properties than the CZA without Nd2O3, and the addition of Nd203 improved the catalytic activity of TWC. Especially, the CZAN-i support prepared by impregnation method had better thermal stability and redox property. Meanwhile, the Pd/CZAN-i catalyst exhibited the best catalytic performance. XPS measurements indicated that the Nd-modified samples possessed more Ce3＋ and oxygen vacancies on the surface of samples, which led to a better redox property. The excellent redox property of support materials helped to improve the catalytic activity of TWC.

关 键 词：CeO2-ZrO2-Al2O3 support materials ND2O3 Ce-O-Nd bonds Pd-only three-way catalysts redox property rare earths 

分 类 号：O643.36[理学—物理化学] TQ426.96[理学—化学]