A comparison of hierarchical Pt@CeO2/Si-Al2O3 and Pd@CeO2/Si-Al2O3

作者：Arroyo Ramirez Lisandra^*; Chen Chen; Cargnello Matteo; Murray Christopher B; Gorte Raymond J

来源：Catalysis Today, 2015, 253: 137-141.

DOI：10.1016/j.cattod.2015.01.036

• Platinum
• Ceria Palladium
• Core-shell catalyst
• Coulometric titration
• Water gas shift

A comparison of catalytic and adsorption properties for Pt@CeO2/Si-Al2O3 (1-wt% Pt and 9-wt% CeO2) and Pd@CeO2/Si-Al2O3 (1-wt% Pd and 9-wt% CeO2) core-shell catalysts indicates that the CeO2 shell is stable for Pd but not for Pt. Following calcination at 773K, Pt@CeO2/Si-Al2O3 exhibits water-gas-shift (WGS) rates in 3% H2O and CO that are similar to rates found on conventional Pt/CeO2, implying that there is good contact between the Pt and CeO2 phases, even at the relatively low CeO2 loading. WGS rates on Pt@CeO2/Si-Al2O3 were also reasonably stable with time and unaffected by pre-reduction of the catalyst. By comparison, WGS rates over Pt@CeO2/Si-Al2O3 declined rapidly due to reduction of CeO2 and were suppressed by pre-reduction of CeO2. After calcination to 1073 K, large metal particles were observed with Pt@CeO2/Si-Al2O3, but not on Pt@CeO2/Si-Al2O3. Coulometric titration measurements on these two materials suggest stronger interactions between CeO2 and Pd and these are likely responsible for the higher stability of the core-shell structure in Pd@CeO2 compared to Pd@CeO2. 2015 Elsevier B.V.

• 出版日期2015-9-15