摘要
The physicochemical properties of Pt-,Pd-and Rh-loaded(Ce,Zr,La)O_(2)(shorted for CZL)catalysts before/after aging treatment were systematically characterized by various techniques to illustrate the relationship of the dynamic oxygen storage/release capacity and redox ability with their catalytic performances for HC,NO_(x)and CO conversions.Pt/CZL catalyst exhibits the optimum catalytic performance for HC and NO_(x)elimination,which mainly contribute to its excellent redox ability and dynamic oxygen storage/release capacity(DOSC)at lower temperature due to the stronger PM(precious metals)-support interaction.However,the worse stability of Pt-O-Ce species and volatile Pt oxides easily result in the dramatical decline in catalytic activity after aging.Pd/CZL shows higher catalytic activity for CO conversion by reason of more Olatt species as the active oxygen for CO oxidation reaction.Rh/CZL catalyst displays the widest dynamic operation window for NO_(x)elimination as a result of greater oxygen mobility at high temperature,and the ability to retain more Rh-O-Ce species after calcined at 1100℃effectively restrains sintering of active RhOx species,improving the thermal stability of Rh/CZL catalyst.
基金
This work was supported by Key Program of Science Technology Department of Zhejiang Province(No.2018C03037).
