Probing surface-sensitive redox properties of VO x /TiO 2 catalyst nanoparticles

Redox processes of oxide materials are fundamental in catalysis. These processes depend on the surface structure and stoichiometry of the oxide and are therefore expected to vary between surface facets. However, there is a lack of direct measurements of redox properties on the nanoscale for analysin...

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Bibliographic Details
Published in:Nanoscale 2021-04, Vol.13 (15), p.7266-7272
Main Authors: Ek, Martin, Arnarson, Logi, Georg Moses, Poul, Rasmussen, Søren B, Skoglundh, Magnus, Olsson, Eva, Helveg, Stig
Format: Article
Language:English
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Summary:Redox processes of oxide materials are fundamental in catalysis. These processes depend on the surface structure and stoichiometry of the oxide and are therefore expected to vary between surface facets. However, there is a lack of direct measurements of redox properties on the nanoscale for analysing the importance of such faceting effects in technical materials. Here, we address the facet-dependent redox properties of vanadium-oxide-covered anatase nanoparticles of relevance to, e.g., selective catalytic reduction of nitrogen oxides. The vanadium oxidation states at individual nanoscale facets are resolved in situ under catalytically relevant conditions by combining transmission electron microscopy imaging and electron energy loss spectroscopy. The measurements reveal that vanadium on {001} facets consistently retain higher oxidation states than on {10l} facets. Insight into such structure-sensitivity of surface redox processes opens prospects of tailoring oxide nanoparticles with enhanced catalytic functionalities.
ISSN:2040-3364
2040-3372
DOI:10.1039/D0NR08943E