title: Promoting effect of alkaline earth metal doping on catalytic activity of HC and NOx conversion over Pd-only three-way catalyst.
abstract: The influence of alkaline earth metal (M=Mg, Ca, Sr and Ba) promoter on the structural/textural properties of Ce0.67Zr0.33O2 (designated as CZ) and the catalytic behavior of its supported Pd-only three-way catalyst (Pd/CZM) have been investigated. The results show that the modification with alkaline earth metal obviously improves the catalytic activity for hydrocarbon (HC) and nitrogen oxides (NOx) conversion, especially the introduction of Ba. Furthermore, the operation window of the promoted catalysts has also been widened. The doping of alkaline earth metal leads to the formation of more homogeneous Ce-Zr-M ternary solid solution with higher surface area and smaller crystallite size, and the corresponding Pd/CZM catalysts present improved reducibility of PdO species. The modification with Ca, Sr and Ba improves the thermal aging resistance, especially Ba. DRIFTS results reveal that the doping of alkaline earth metal enhances the oxygen and electron transfer ability and favors the dissociation of NO, which promotes the activation and storage capacity of the acidic atoms like NOx, and leads to enhanced catalytic activity performance.
authors: Institute of Catalysis, Zhejiang University, Hangzhou 310028, China.
authors: Linyan
authors: L
authors: Yang
authors: Institute of Catalysis, Zhejiang University, Hangzhou 310028, China.
authors: Siyu
authors: S
authors: Lin
authors: Institute of Catalysis, Zhejiang University, Hangzhou 310028, China.
authors: Xue
authors: X
authors: Yang
authors: Institute of Inorganic and Material Chemistry, Zhejiang University, Hangzhou 310028, China.
authors: Weimin
authors: W
authors: Fang
authors: Institute of Catalysis, Zhejiang University, Hangzhou 310028, China. Electronic address: zhourenxian@zju.edu.cn.
authors: Renxian
authors: R
authors: Zhou
mesh_terms: D002384:Catalysis; D006838:Hydrocarbons / Q000737:chemistry*; D008673:Metals, Alkaline Earth / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D006838:Hydrocarbons; D008673:Metals, Alkaline Earth; D009589:Nitrogen Oxides; D010165:Palladium
keywords: Alkaline earth; Ce(0.67)Zr(0.33)O(2); Pd-only three-way catalyst; Structural promotion