Copper(Cu)-based electrocatalysts are a unique class of catalysts for the production of C2+ chemicals and fuels in the process of electrochemical reduction of CO2, but the stability of Cu-based electrocatalysts has largely hindered their practical application. Based on this,Prof. Luo Langli and Prof. Chen Xing (co-corresponding author) of Tianjin University, et alThe origin and structural evolution of the instability of Cu2O nanocubic electrocatalysts were studied using Cu2O nanocubic as a model catalyst, and tracked by detailed electron microscopy analysis and theoretical calculations.
Using DFT calculations, the authors evaluated the stability of the "Cu-O-H" phase derived from the Cu2O surface. By selectively replacing the Cu atom in Cu2O with the H atom, the Cu-O-H structure is formed. The optimized structure shows that the reduced Cu-O-H is stable above the Cu2O phase, that is, the Cu-O-H phase is the initial reduction induced by the surface chemical environment. In Region II, the authors observed that the Cu atoms were separated from the surface and that their atomic structures did not follow the atomic registry of the Cu2O substrate, indicating that the epitaxial relationship between the newly formed "Cu-O-H" lattice and the original Cu2O lattice could not be maintained as the reaction progressed.
The typical theory of H2 or CO redox begins with the formation of an anaerobic phase and surface remodeling induced by chemical species, e.g. located in (3, 0;1, 1) Preferential adsorption of H atoms at the oxygen site at the bottom of the intrinsic atomic column on the surface and the formation of Cu2O heptagon. Under CO2RR electrochemical reduction conditions, the authors found a unique "Cu-O-H" phase as the first step in reduction, which is difficult to be caused solely by atomic recombination. In addition, the lack of Cu surface structure leads to the formation of oxide surface Cu nanoislands, which are considered to be a key feature of Stage I.
structural evolution of cu2o nanocube electrocatalysts for the co2 reduction reaction. nano energy,, doi: 10.1016/j.nanoen.2022.108080.