Size-Engineered PdCd Nanocubes Enable Intermediate Desorption for Enhanced Durability in Ethylene Glycol Electrooxidation.

The ethylene glycol oxidation reaction (EGOR) is crucial for direct liquid fuel cells and the electrochemical upcycling of poly(ethylene terephthalate), yet its practical implementation is limited by rapid performance deactivation caused by strongly adsorbed carbonaceous intermediates. In this work, we report a colloidal synthesis method for producing monodisperse PdCd intermetallic nanocubes with precisely controlled sizes ranging from 8 to 12 nm. The ordered intermetallic structure combined with size-dependent surface electronic states significantly enhances EGOR activity and durability in alkaline media. Notably, 12 nm PdCd nanocubes deliver a high mass activity of 2.05 A mg and demonstrates exceptional operational stability maintained over 72 h. The improved performance is attributed to its strong resistance to CO poisoning and weak adsorption of reaction intermediates such as glycolic acid. Density functional theory (DFT) calculations reveal a downshifted d-band center, reduced intermediate binding ability, and lower barriers for the potential-determining step. This work offers a rational design strategy for the development of advanced intermetallic nanocrystals as high-performance EGOR electrocatalysts.