Sinter- and Water-Resistant Pt Enabled by High Entropy of Porous Oxide Nanofibers

Supported ultrafine noble metal species, especially for Pt, suffer from inevitable sintering at temperatures as low as 80 °C, severely limiting their stability and thus their practical applications. In this work, a strategy is demonstrated using the high-entropy effect to prevent sub-2.6 nm Pt nanoparticles from sintering. Due to the higher mixing entropy and thus lower Gibbs free energy of porous high-entropy oxide (HEO) nanofibers in the catalytic system, the supported Pt remained thermally stable up to 1000 °C, as verified by in situ HAADF-STEM observation. Even after being hydrothermally aged with 10 vol% vapor at 850 °C, this catalytic system maintained the Pt size of 2.9 nm, demonstrating remarkable sinter-resistance and water tolerance. Particularly, after aging at 850 °C, the Pt/HEO catalytic system maintained its full CO conversion for 338 h without any decline. These results highlight the positive effect of increasing configurational entropy on the thermal stability of the entire catalytic system, providing a reliable solution for catalytic conversions involving high temperatures.