Imaging the Breathing of a Platinum Nanoparticle in Electrochemical Environment

Surface strain is widely used in gas phase catalysis and electrocatalysis to control the binding energies of adsorbates on metal surfaces. However, $in$ $situ$ or $operando$ strain measurements are experimentally challenging, especially on nanomaterials. Here, we take advantage of the 4$^{th}$ generation Extremely Brilliant Source at the European Synchrotron Radiation Facility (ESRF-EBS, Grenoble, France) to quantify the distribution of strain inside a Pt nanoparticle, and to determine its morphology in an electrochemical environment. Our results show for the first time evidence of heterogeneous and potential-dependent strain distribution between highly-coordinated ({100} and {111} facets) and under-coordinated atoms (edges and corners) as well as evidence of strain propagation from the surface to the bulk of the nanoparticle. These results provide dynamic structural insights to better simulate and design efficient nanocatalysts for energy storage and conversion applications.