New Insight into the Doping Effect of Pr2O3 on the Structure-Activity Relationship of Pd/CeO2-ZrO2 Catalysts by Raman and XRD Rietveld Analysis

作者：Yang, Xue; Yang, Linyan; Lin, Siyu; Zhou, Renxian^*

来源：Journal of Physical Chemistry C, 2015, 119(11): 6065-6074.

DOI：10.1021/jp512606m

• OXYGEN STORAGE CAPACITY
• MIXED OXIDES
• SOLID-SOLUTIONS
• REDOX PROPERTIES
• IN-SITU
• CERIA
• PERFORMANCE
• CE
• LA
• PR

Pd/CeO2-ZrO2-Pr2O3 (CZP) catalysts were synthesized with different Ce/Zr molar ratios and 8.0 wt % Pr2O3 doping. Their structures were characterized by various techniques, especially using X-tar diffraction (XRD) in combination with Rietveld refinement and Raman analysis. The XRD pattern of CZP with Ce/Zr molar ratios >1 can be indexed satisfactorily to the fluorite structure with a space group Fm-3m. When the Ce/Zr molar ratio reaches 1/2, the XRD patterns only display diffraction peaks of the tetragonal phase (S.G. P4(2)/nmc). The Pr additive in the crystal lattice mainly replaces the position of Ce, which improves the redox reaction activity of catalysts when compared with Pr-free catalysts. Rain an results reveal the enrichment of defect sites on the surface. The presence of Moderate ZrO2 an increase both oxygen vacancies and the ZrO8-type complex in supports, which is in accord with the change regularity of their oxygen storage capacity (OSC) values. Moreover, the addition of moderate Zr and Pr promotes the catalytic activity of NO,, HC, and CO conversions and thermal stability and obviously widens the operational window clue to their larger number of oxygen vacancies and higher OSC value, especially for Pd/CZP catalysts with Ce/Zr molar ratios from 2/1 to 1/2.

• 出版日期2015-3-19
• 单位浙江大学