CeO2-ZrO2-La2O3-Al2O3 composite oxide and its supported palladium catalyst for the treatment of exhaust of natural gas engined vehicles

• Published in: Journal of natural gas chemistry Vol. 18; no. 2; pp. 139 - 144
• Main Authors: Zhang, Xiaoyu, Long, Enyan, Li, Yile, Guo, Jiaxiu, Zhang, Lijuan, Gong, Maochu, Wang, Minghua, Chen, Yaoqiang
• Format: Journal Article
• Language: English
• Published: Chengdu Dalian Institute of Chemical Physics 01.06.2009; Key Laboratory of Green Chemistry & Technology of the Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, Sichuan,China%College of Architecture and Environment, Sichuan University, Chengdu 610064, Sichuan, China%State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China%Sichuan Tianyi Science & Technology Co., Ltd., Chengdu 610225, Sichuan, China
• Subjects: Air pollution caused by fuel industries; Al2O3; Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Pollution reduction; 复合氧化物; 天然气发动机; 氧化铈; 氧化锆; 氧化镧; 负载钯催化剂; Methane; Nitrogen oxide; Air pollution control; NO; Palladium; Al; Cerium oxide; CeO; Supported catalyst; Lanthanum oxide; O; natural gas vehicles exhaust; La; ZrO; Exhaust gas; Raman spectrometry; Pd catalysts; X ray diffractometry; Performance; Catalyst activity; Natural gas; conversion; methane oxidation; CeO2-ZrO2-Al2O3; NOx conversion; La2O3
• ISSN: 1003-9953
• DOI: 10.1016/S1003-9953(08)60092-4

Composite supports CeO2-ZrO2-Al2O3（CZA） and CeO2-ZrO2-Al2O3-La2O3（CZALa） were prepared by co-precipitation method. Palladium catalysts were prepared by impregnation and their purification ability for CH4, CO and NOx in the mixture gas simulated the exhaust from natural gas vehicles （NGVs） operated under stoichiometric condition was investigated. The effect of La2O3 on the physicochemical properties of supports and catalysts was characterized by various techniques. The characterizations with X-ray diffraction （XRD） and Raman spectroscopy revealed that the doping of La2O3 restrained effectively the sintering of crystallite particles, maintained the crystallite particles in nanoscale and stabilized the crystal phase after calcination at 1000 ℃. The results of N2-adsorption, H2-temperatnre-programmed reduction （H2-TPR） and oxygen storage capacity （OSC） measurements indicated that La2O3 improved the textural properties, reducibility and OSC of composite supports. Activity testing results showed that the catalysts exhibit excellent activities for the simultaneous removal of methane, CO and NOx in the simulated exhaust gas. The catalysts supported on CZALa showed remarkable thermal stability and catalytic activity for the three pollutants, especially for NOx. The prepared palladium catalysts have high ability to remove NOx, CH4 and CO, and they can be used as excellent catalysts for the purification of exhaust from NGVs operated under stoichiometric condition. The catalysts reported in this work also have significant potential in industrial application because of their high performance and low cost.