Modification Ceria-Zirconia Mixed Oxides by Doping Sr Using the Reversed Microemulsion for Improved Pd-Only Three-Way Catalytic Performance

Abstract

A reversed microemulsion was first adopted to prepare the Ce−Zr−Sr ternary mixed oxide with different Sr content. The Pd-only three-way catalyst (TWC) was obtained by incipient wetness impregnation with 0.5 wt % Pd loading. The structural and oxygen handling properties have been analyzed by XRD, Raman, H2-TPR, and the dynamic oxygen storage capacity (DOSC). The Sr doping resulted in improved phase thermal stability and the low-temperature activity. The introduction Sr into ceria−zirconia lattice strongly modified the mobility of oxygen and enhanced the DOSC performance. Pd-only TWC based on the Ce0.67Zr0.33Sr0.03O2.03 support exhibited superior activity for C3H8 and NO conversion and amplified amplitude of the stoichiometric window.