Structural changes in noble metal nanoparticles during CO oxidation and their impact on catalyst activity.

ABSTRACT: The dynamical structure of a catalyst determines the availability of active sites on its surface. However, how nanoparticle (NP) catalysts re-structure under reaction conditions and how these changes associate with catalytic activity remains poorly understood. Using operando transmission electron microscopy, we show that Pd NPs exhibit reversible structural and activity changes during heating and cooling in mixed gas environments containing O₂ and CO. Below 400 °C, the NPs form flat low index facets and are inactive towards CO oxidation. Above 400 °C, the NPs become rounder, and conversion of CO to CO₂ increases significantly. This behavior reverses when the temperature is later reduced. Pt and Rh NPs under similar conditions do not exhibit such reversible transformat

SUBMITTER: Chee SW 

PROVIDER: S-EPMC7195460 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature