The imperative to capture and convert CO2 into high value-added chemicals or fuels represents one of the most significant challenges in achieving a sustainable society. This reaction can be performed in the gas phase at high temperature but also electrochemically, at low temperature, not only mitigating the greenhouse effect, but also providing a way to store energy by transforming intermittent renewable electricity into high added value chemicals. This project aims to investigate the structural evolution of individual nanocrystals during CO2 reduction reactions. Using the unique capabilities of Bragg coherent X-ray imaging, we can dynamically map, in situ and operando, the three-dimensional changes in lattice deformation, strain, composition, and crystallographic defects of nano-crystallites, establishing a comprehensive experimental framework for structure-chemistry-performance relationships. The experiments will be conducted at ESRF, the European synchrotron facility located in Grenoble, in close proximity to CEA-Grenoble, within a leading international scientific environment. The project will be in collaboration with LEPMI (Laboratory of Electrochemistry and Physico-chemistry of Materials and Interface, Grenoble-France), which has expertise in electrocatalysis, materials science, and energy storage and conversion systems.