Study of Pt dispersion on Ce based supports and the influence on the CO oxidation reaction

• Pt loaded on different supports is subjected to hydrothermal treatment.
• Pt dispersion is dependent of the Ce contents of supports.
• Higher CO oxidation activity is reflected in the Ce rich supports.
• The TOF of CO oxidation increases as Pt dispersion increasing.
• Pt–O–Ce plays the critical role for the high CO oxidation.

The effect of Pt dispersion on the different supports was evaluated. The Pt structural and textural properties have been analyzed by XRD, HRTEM and CO pulse chemisorptions. The redox and structure property between Pt and supports was characterized by H2-TPR and Raman. CO-DRIFTS characterized the identification of Pt coordination. Results demonstrate that the Pt dispersion is dependent of Ce contents of supports. The Pt supports interaction tends to become weak as Ce content decreasing, leading to higher reduction temperature for active oxygen at low temperature. The stronger interaction for Pt loaded on CeO2 and Ce0.7Zr0.3O2 results in superior CO oxidation performance. The TOF for Pt loaded on Ce based supports presents linear increasing as Pt dispersion increasing.

The HADDF and HRTEM results for aged Pt loaded on treated CeO2 and aged Pt loaded on fresh CeO2 (left). The relevance of Pt particle sizes and H2 consumption amount by H2-TPR (below 500 °C) with the Ce contents (right)Figure optionsDownload as PowerPoint slide