A comparative study of SrO and BaO doping to CeO2ZrO2: Characteristic and its catalytic performance for three-way catalysts

Ceria-zirconia-strontia (Ce0.35Zr0.55Sr0.10O1.9) and ceria-zirconia-baria (Ce0.35Zr0.55Ba0.10O1.9) were synthesized using an oxidation-co-precipitation method with hydrogen peroxide (H2O2) as oxidant. The physical and chemical properties of the prepared materials were investigated using Brunauer–Emmett–Teller surface area characterization, transmission electron microscopy, X-ray diffraction, Raman spectra, X-ray photoelectron spectroscopy, and oxygen pulse reaction. The prepared materials were used in preparing three-way catalysts with low Pt and Rh content. Moreover, catalytic activities were evaluated at a fixed bed under a simulated gaseous mixture. The results are as follows: (1) the prepared materials have a face-centered cubic structure and are nano-sized; (2) aged Ce0.35Zr0.55Sr0.10O1.9 has higher oxygen storage capacity (494 μmol/g), better thermal stability (30 m2/g), good low-temperature reducibility, and high hydrogen uptake after TPR-redox cycles; (3) the light-off temperature (T50) of Pt-Rh/CZS/LA can be as low as 199 °C for CO, 228 °C for NO, and 252 °C for C3H8; and (4) Pt-Rh/CZS/LA has a fairly wide working-window.

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► The prepared materials have a face-centered cubic structure and nanosize particles.
► Comparing to CZB, aged CZS has 494 μmol/g of OSC and 30 m2/g of surface area.
► CZS and CZB have similar NO sorption and reductive properties and different H2 uptake.
► T50 of Pt-Rh/CZS/LA is as low as 199 °C for CO, 228 °C for NO, and 252 °C for C3H8.
► Pt-Rh/CZS/LA has wider working-window at 320 °C under different λ value.