Synthesis and Catalytic Performance of High-Entropy Rare-Earth Perovskite Nanofibers: (Y 0.2 La 0.2 Nd 0.2 Gd 0.2 Sm 0.2 )CoO 3 in Low-Temperature Carbon Monoxide Oxidation.

This study investigated the catalytic properties of low-temperature oxidation of carbon monoxide, focusing on (Y 0.2 La 0.2 Nd 0.2 Gd 0.2 Sm 0.2 )CoO 3 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 (Y 0.2 La 0.2 Nd 0.2 Gd 0.2 Sm 0.2 )CoO 3 , 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 (Y 0.2 La 0.2 Nd 0.2 Gd 0.2 Sm 0.2 )CoO 3 , 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 (Y 0.2 La 0.2 Nd 0.2 Gd 0.2 Sm 0.2 )CoO 3 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.