Journal of University of Chinese Academy of Sciences >
Shape-dependent effects of nanoceria on the activity of Pd/CeO2 catalysts for CO oxidation
Received date: 2015-04-13
Revised date: 2015-06-15
Online published: 2015-09-15
The redox property of palladium nanoparticles (NPs) is pivotal to CeO2 supported Pd catalysts in oxidation reactions and is closely related to the structure of Pd-CeO2 interface. Herein, we report that low-temperature CO oxidation activity of Pd/CeO2 highly depends on the shape and crystal plane of CeO2 supports. Pd/CeO2 catalysts with CeO2 nanoocthedrons (NOCs) and nanocubes (NCs) as supports were prepared by colloidal-deposition method. Results show that Pd/CeO2 NOCs with ceria {111} facets enclosed exhibited much higher catalytic activity than Pd/CeO2NCs with ceria {100} facets exposed. DFT calculations revealed that the redox property of surface Pd species may play important roles in determining the reducibility and activity of catalysts. The PdOx to Pd cycle is more facile on Pd4@CeO2(111) than on Pd4@CeO2(100), which is dictated by the Pd-ceria interaction in the end. Our results show that the redox property of surface Pd is pivotal to the reducibility and activity of Pd/ceria catalysts, which could be tuned by manipulation of the Pd-CeO2 interaction via tuning the exposed facets of ceria support.
Key words： Pd/CeO2 interface; shape-dependent; CO oxidation; nanocube; nanooctahedron
WANG Lei , MAO Junyi , YUAN Qing , HUANG Tao . Shape-dependent effects of nanoceria on the activity of Pd/CeO2 catalysts for CO oxidation[J]. Journal of University of Chinese Academy of Sciences, 2015 , 32(5) : 594 -604 . DOI: 10.7523/j.issn.2095-6134.2015.05.004
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