The need for CO2 capture and conversion to value-added chemicals or fuels represents one of the greatest challenges for the transition to a sustainable society. Electrocatalysts play a key role in determining the product selectivity and overpotential in CO2 reduction reaction (CO2R). The use of Cu and alloyed Cu nanoparticles is a promising strategy to tune the catalytic properties. Using spectroscopic Bragg Coherent X-ray Diffraction Imaging (spectro-BCDI), we intend to reveal both structural (lattice strain, defect(s), facets and morphology) and chemical (composition and oxidation states) characteristics of alloyed Cu catalysts under electrochemical conditions, and provide guidelines for designing both effective and selective CO2 reduction catalysts.