LAUSR

Transition metal oxide catalysts have been the focus of recent research for the oxygen reduction reaction (ORR). However, the relationship between morphology and electrocatalysis of metal oxide catalysts has not been well studied or understood hitherto. In the present work, cuprous oxides (Cu2O) with three different morphologies (sphere, octahedron, and truncated octahedron) have been synthesized employing a potentiostatic electrodeposition method. The as-prepared Cu2O has been characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Three different shapes of Cu2O crystals were used to study the shape-dependent electrocatalytic properties for ORR in alkaline media. It was found that the surface-specific activity of Cu2O with truncated octahedron shape toward ORR was higher than that of Cu2O with a sphere or octahedron morphology. The morphology–activity relationship of Cu2O as a cathode catalyst was further studied through periodic spin density functional theory (DFT) calculations. Comprehensive analysis of electrocatalysis exiperiments and DFT calculations reveals that Cu2O as a truncated octahedron preferentially exposes the (100) crystal planes, which are beneficial to stronger O2 adsorption and easier activation of adsorbed O2 on the surface of Cu2O. This finding furthers our understanding of Cu2O catalysis and provides new light on the relevant catalyst design criteria.