Carbon-Supported High-Entropy Oxide Nanoparticles as Stable Electrocatalysts for Oxygen Reduction Reactions

Nanoparticles supported on carbonaceous substrates are promising electrocatalysts. However, achieving good stability for the electrocatalysts during long-term operations while maintaining high activity remains a grand challenge. Herein, a highly stable and active electrocatalyst featuring high-entropy oxide (HEO) nanoparticles uniformly dispersed on commercial carbon black is reported, which is synthesized via rapid high-temperature heating (approximate to 1 s, 1400 K). Notably, the HEO nanoparticles with a record-high entropy are composed of ten metal elements (i.e., Hf, Zr, La, V, Ce, Ti, Nd, Gd, Y, and Pd). The rapid high-temperature synthesis can tailor structural stability and avoid nanoparticle detachment or agglomeration. Meanwhile, the high-entropy design can enhance chemical stability to prevent elemental segregation. Using oxygen reduction reaction as a model, the 10-element HEO exhibits good activity and greatly enhances stability (i.e., 92% and 86% retention after 12 and 100 h, respectively) compared to the commercial Pd/C electrocatalyst (i.e., 76% retention after 12 h). This superior performance is attributed to the high-entropy compositional design and synthetic approach, which offers an entropy stabilization effect and strong interfacial bonding between the nanoparticles and carbon substrate. The approach promises a viable route toward synthesizing carbon-supported high-entropy electrocatalysts with good stability and high activity for various applications.

Automated summary

This study presents a highly stable and active electrocatalyst with high-entropy oxide (HEO) nanoparticles uniformly dispersed on commercial carbon black, synthesized via rapid high-temperature heating with ten metal elements. The electrocatalyst exhibits good stability and activity during long-term operation, attributed to the high-entropy design and synthetic approach that provide an entropy stabilization effect and strong interfacial bonding between the nanoparticles and carbon substrate.