Unraveling the Active Phase of Copper Alloys during Electrochemical CO2 Reduction by Bragg Coherent Diffraction Imaging

Identifying the chemical and structural changes of catalysts under reaction conditions is crucial in terms of understanding the catalytic mechanism and improves the process efficiency, which facilitates the next-generation catalysts design. In alloyed Cu nanoparticle system, the distribution of CO2 reduction products is closely related to the surface and near-surface catalyst composition. By controlling the atomic ratio in Cu alloys, the bond structure as well as the electronic properties can be tuned to affect the binding energy of CO2 reduction intermediates. Additionally, alloying also changes the surface strain and binding modes of intermediates regardless of the scaling relations. With this proposed in situ electrochemical Bragg Coherent Diffraction Imaging (BCDI) experiment, we aim to resolve the local strains of Cu alloys (Cu-Ag or Cu-Pd) with a resolution as low as 10 nm to identify the active phase during electrochemical CO2 reduction.