Synthesis and Catalytic Performance of High-Entropy Rare-Earth Perovskite Nanofibers: (Y0.2La0.2Nd0.2Gd0.2Sm0.2)CoO3 in Low-Temperature Carbon Monoxide Oxidation

Abstract

This study investigated the catalytic properties of low-temperature oxidation of carbon monoxide, focusing on (Y0.2La0.2Nd0.2Gd0.2Sm0.2)CoO3 synthesized via a glycothermal method using 1,4-butanediol and diethylene glycol at 250 °C. This synthesis route bypasses the energy-intensive sintering process at 1200 °C while maintaining a high-entropy single-phase structure. The synthesized material was characterized structurally and chemically by X-ray diffraction and SEM/EDX analyses. The material was shown to form nanofibers of (Y0.2La0.2Nd0.2Gd0.2Sm0.2)CoO3, thereby increasing the active surface area for catalytic reactions, and crystallize in the model Pbnm space group of distorted perovskite cell. Using a custom setup to investigate catalytic properties of (Y0.2La0.2Nd0.2Gd0.2Sm0.2)CoO3, the CO oxidation behavior of those high-entropy perovskite oxide was investigated, showing an overall conversion of 78% at 50 °C and 97% at 100 °C. These findings highlight the effective catalytic activity of nanofibers of (Y0.2La0.2Nd0.2Gd0.2Sm0.2)CoO3 under mild conditions and their versatility in various catalytic processes of robust CO neutralization. The incorporation of rare-earth elements into a high-entropy structure could impart unique catalytic properties, promoting a synergistic effect that enhances performance.