Ce Salt-Assisted Construction of Bilayer Cu–Ce–O Nanostructure Arrays on Cu Foil Enhances Methanol Oxidation Performance

The construction of highly ordered nanostructures on copper offers significant advantages in energy conversion electrocatalysis, particularly as a potential alternative to platinum-based precious metal catalysts in the methanol oxidation process to prevent catalytic poisoning. However, the self-assembly and ordered growth of nanostructures on copper has been a research challenge. Herein, we report a Ce salt-assisted electrooxidation strategy for the first time to prepare bilayer Cu-Ce-O nanostructures on copper, containing Cu₂O-Ce₂O₃ nanorods on the top and Cu₂O nanoparticles next to the substrate. The incorporation of Ce salts into the electrolyte enables the controllable oriented growth of nanostructures from cubic nanoparticles to nanorods. Moreover, the high activity surface area of nanorods demonstrates enhanced catalytic activity and long-term stability (6 h) in methanol oxidation, exhibiting a current density of 71.5 mA cm^-2 and 72 mV lower onset overpotential compared to blank Cu foil. Density functional theory calculations also demonstrate that Cu₂O enhances the adsorption of CH₃OH. This strategy provides new insights into the rational construction of sophisticated copper-based nanostructures, showing promising potential for applications in methanol catalysis.