Title

Role And Evolution Of Nanoparticle Structure And Chemical State During The Oxidation Of No Over Size- And Shape-Controlled Pt/Γ-Al2O 3 Catalysts Under Operando Conditions

Keywords

EXAFS; mass spectroscopy; nanoparticle redispersion; NO oxidation; Pt nanoparticle; TEM; XANES

Abstract

The structure and chemical state of size-selected Pt nanoparticles (NPs) supported on γ-Al2O3 were studied during the oxidation of NO using X-ray absorption near-edge spectroscopy and extended X-ray absorption fine-structure spectroscopy measurements under operando conditions. The data revealed the formation of PtOx species in the course of the reaction that remained present at the maximum temperature studied, 350 °C. The PtOx species were found in all samples, but those with the smallest NPs showed the highest degree of oxidation. Moreover, NO-induced nanoparticle redispersion was observed at temperatures below 150 °C for all catalysts studied. Catalytic tests showed activity toward the oxidation of NO for all samples. Nevertheless, the catalyst with the smallest NPs was found to be the least active, which is explained by a more extensive formation of PtOx species in this catalyst and their detrimental contribution to the oxidation of NO. © 2014 American Chemical Society.

Publication Date

6-6-2014

Publication Title

ACS Catalysis

Volume

4

Issue

6

Number of Pages

1875-1884

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1021/cs500137r

Socpus ID

84902124172 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84902124172

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