Electrochemical CO2 reduction offers a promising route to net-zero by closing the carbon cycle. Cu has been shown to be the only metal that can catalyse the transfer of more than two electrons during CO2RR, thus, generating more valuable fuels including CH4 or even C2+ molecules. Nanoporous Cu, produced by dealloying brass (Cu–Zn), exhibits high surface distortion and abundant undercoordinated atoms, leading to pronounced ligament surface strain (LSS). Our recent studies, done at ESRF and Imperial, shows that such LSS caused by undercoordinated atoms acts to enhance the catalytic properties of Cu for CO2RR. However, due to the high surface mobility of Cu atoms, and the extremely harsh cathodic condition of CO2RR, preserving such high LSS still remians challenging. The use of synchrotron-based diffraction method will enable the detailed observation of how dealloying-induced Cu LSS evolves during the CO2RR condition, which can help us outline new strategies for CO2RR catalyst design.