We performed operando Bragg coherent X-ray diffraction imaging under CO oxidation,as well as oxidizing conditions on a pre-characterized single PtRh nanoparticleand found that this (111) oriented particle with truncated octahedral shape is twinnedwith a Σ3 twin boundary parallel to the SrTiO3 (001) support, at the height of thenanoparticle edges. We observed that the average strain at the twin boundary is higherunder CO oxidation conditions compared to pure CO or O2. In addition, we observedthat two new facets were forming during the oxidizing/reducing cycles. Furthermore,we found mixed edge/screw dislocations at the twin boundary, but only where the{111} side facets meet. Inducing such dislocations changes the local strain and theatomic structure of the nanoparticles, which may create more active sites close to thenanoparticle edges.

ACS nano 19(26), 23552 - 23563 (2025). doi:10.1021/acsnano.4c15457

Published by Soc., Washington, DC