CO oxidation under lean and stoichiometric conditions over ceriazirconia with very low metal contents(Cu,Co,Ag and Pt)  

作　　者：J.C.Martínez-Munuera M.P.Yeste A.García-García 

机构地区：[1]MCMA Group,Department of Inorganic Chemistry and Institute of Materials,University of Alicante,Carretera de San Vicente del Raspeig s/n,03690,San Vicente del Raspeig,Alicante,Spain [2]Solid Chemistry and Catalysis Group,Department of Materials Science,Metallurgic Engineering and Inorganic Chemistry,Institute of Electronic Microscopy and Materials Research,University of Cádiz,Ap.40,E-11510,Puerto Real,Cádiz,Spain

出　　处：《Journal of Rare Earths》2024年第9期1669-1681,I0002,共14页稀土学报（英文版）

基　　金：Project supported by the Spanish Ministry of Science and Innovation/Research Spanish Agency (PID2019-105 542RB-100/AEI/10.13039/501100011033);the UE-FEDER funding and Generalitat Valenciana (CIPROM/2021/070)。

摘　　要：In this work,several ceria-zirconia based catalysts with very lo w(and equimolar) metal contents were prepared,characterised and tested for the CO oxidatio n reaction(under lean and stoichiometric conditions),trying to emulate those conditions found in a diesel oxidation catalyst(DOC) system from a diesel engine and those encountered under gasoline exhaust(λ=1).The metals chosen are Cu,Co,Ag and Pt(as a reliable benchmark).The results reveal enormous differences among reducibility and catalytic activity despite quite similar structural and textural properties of the catalysts,showing differences among dispersion(Ag-catalyst seems to present a low level of dispersion).This catalyst seems to be characterised,as well,by a strong electronic interaction between Ce and Ag centres which is suggested to yield an improved reducibility under H_(2)-TPR conditions.Nevertheless,the order in catalytic activity(Cu>Ag>Co≈Pt>>support) seems not to follow the order found in reducibility and the Cu-catalyst seems to be the most active independently on the reaction conditions,yielding nearly overlapped CO oxidation catalytic curves.Inte restingly,a stro ng correlation between the catalytic activity under the two conditions tested and the OSC values of the Ce_(0.8)Zr_(0.2)O_(2)-supported metal catalysts is found.Therefore,OSC parameter measured at 150℃ can be used as a relevant descriptor to evaluate the CO oxidation activity at low and medium conversions for the investigated catalysts,much better than the H_(2)-TPR measurements.

关 键 词：CO oxidation Low metal content CERIA-ZIRCONIA Copper species OSC parameter Rare earths 

分 类 号：TQ426.96[化学工程]