Engineering Active Sites of Gold-Cuprous Oxide Catalysts for Electrocatalytic Oxygen Reduction Reaction

Abstract

Understanding how the catalyst morphology influences surface sites is crucial for designing active and stable catalysts and electrocatalysts. We here report a new approach to this understanding by decorating gold (Au) nanoparticles on the surface of cuprous oxides (Cu2O) with three different shape morphologies (spheres, cubes, and petals). The Au-Cu2O particles are dispersed onto carbon nanotube (CNT) matrix with high surface area, stability, and conductivity for oxygen reduction reaction. A clear morphology-dependent enhancement of the electrocatalytic activity is revealed. Oxygenated gold species (AuO–) are found to coexist with Au0 on the cube and petal catalysts, whereas only Au0 species are present on the sphere catalyst. The AuO– species function effectively as active sites, resulting in the improved catalytic performance by changing the reaction mechanism. The enhanced catalytic performance of the petal-shaped catalyst in terms of onset potential, half-wave potential, diffusion-limited current density, and stability is closely associated with the presence of the most abundant AuO– species on its surface. Highly active AuO– species are identified on the surface of the catalysts as a result of the unique structural characteristics, which is attributed to the structural origin of high activity and stability. This insight constitutes the basis for assessing the detailed correlation between the morphology and the electrocatalytic properties of the nanocomposite catalysts, which has implications for the design of surface-active sites on metal/metal oxide electrocatalysts.

Laser-ablation assisted strain engineering of gold nanoparticles for selective electrochemical CO2 reduction

“…2d). 41,42 This confirms that all the prepared samples have a pure chemical composition. Such an inference can also be verified by the high-resolution O 1s spectrum of both samples (Fig.…”

Hierarchical Porous Carbon Spheres Loaded CoOX (CoOx/HPCS) for Efficient Oxygen Reduction Reaction in Alkaline Media

“…Besides, some intermediate products like CO groups, such as ‐CO ads , ‐HCHO ads , and ‐HCOOH ads and so on, will be generated during ORR processes on the electrode surface of Pt‐based catalysts, and be adsorbed on catalyst surface, thereby leading to the poisoning of Pt‐based catalysts and the degradation of catalytic activity [52,53] . Therefore, the two crucial factors, those are durability and methanol crossover effect of Pt‐based electrocatalysts, are severely limiting the wide industrial application of fuel cells, especially for the direct methanol fuel cells (DMFCs) [54] . It is of great significance to develop non‐precious metal catalysts with outstanding resistance to methanol toxicity [55] .…”

Review on Metals and Metal Oxides in Sustainable Energy Production: Progress and Perspectives

“…To improve the number of surface-active sites, stability and conduction for oxygen reduction reaction as-developed Au−Cu 2 O catalysts were dispersed over carbon nanotubes. 200 The electrocatalytic investigations have revealed the morphology dependent improved ORR activity of the catalyst. It was observed that the deposited Au showed different oxidation states in morphologically different Cu 2 O catalysts.…”

“…To investigate this fact, Zhang et al have developed a Au deposited Cu 2 O catalyst having different morphologies like petals, cubes, and spheres. To improve the number of surface-active sites, stability and conduction for oxygen reduction reaction as-developed Au–Cu 2 O catalysts were dispersed over carbon nanotubes . The electrocatalytic investigations have revealed the morphology dependent improved ORR activity of the catalyst.…”

“…(b) LSV at a scan rate of 10 mV/s under O 2 saturation. Reprinted with permission from ref . Copyright 2021 American Chemical Society.…”