Highly efficient Pt catalyst on newly designed CeO2-ZrO2-Al2O3 support for catalytic removal of pollutants from vehicle exhaust.

[Display omitted] • A unique two-step incipient wetness impregnation (T-IWI) method was adopted. • A new CeO 2 -ZrO 2 /Al 2 O 3 support with fine Ce 0.9 Zr 0.1 O 2 particles was prepared. • Fine Ce 0.9 Zr 0.1 O 2 particles with rich defects favored Pt anchoring as single sites. • Efficient Pt clusters for CO/HC oxidation was created after H 2 reduction activation. • A clear structure-activity relationship was established in CO oxidation reaction. Pt-CeO 2 catalysts have been widely studied for the vehicle emission control. Designing novel CeO 2 based supports with improved physical-chemical properties has become a research hotspot to further promote the catalytic performance and stability of Pt-CeO 2 catalysts. In this work, through utilizing a unique, two-step incipient wetness impregnation (T-IWI) method for ceria-zirconia-alumina (CZA-T) support preparation, a Pt single site catalyst (Pt/CZA-T) with excellent thermal stability was synthesized. Higher oxidation activity and Oxygen storage capacity (OSC) were achieved on activated Pt/CZA-T, comparing to Pt catalysts on regular CeO 2 /Al 2 O 3 (Pt/CA) and one-step prepared CeZrO x /Al 2 O 3 (Pt/CZA). Via the modification of hydrophilic/hydrophobic properties of γ-Al 2 O 3 by this unique T-IWI method, finer Ce 0.9 Zr 0.1 O 2 particles with higher density of surface defects were formed on CZA-T, on which a higher Pt dispersion and stronger Pt-O-Ce interaction were achieved. Upon activation, smaller, well-dispersed Pt clusters on CZA-T were generated. It was concluded that the CO oxidation performance and OSC were highly related to the size of Pt clusters on different supports that we have developed. More Pt sites located at Pt cluster-CeZrO x interfaces, which were the real active sites, were responsible for the highest OSC function and CO oxidation activity of activated Pt/CZA-T catalyst. [ABSTRACT FROM AUTHOR]