摘要：SummaryHigh-entropy oxides (HEOs) are an emerging class of advanced ceramic materials capable of stabilizing ultrasmall nanoparticle catalysts. However, their fabrication still relies on high-temperature thermal treatment methodologies affording nonporous architectures. Herein, we report a facile synthesis of single-phase, fluorite-structured HEO nanocrystals via an ultrasound-mediated co-precipitation strategy under ambient conditions. Within 15 min of ultrasound exposure, high-quality fluorite-structured HEO (CeHfZrSnErOx) was generated as ultrasmall-sized particles with high surface area and high oxygen vacancy concentration. Taking advantage of these unique structural features, palladium was introduced and stabilized in the form of highly dispersed Pd nanoclusters within the CeHfZrSnErOxarchitecture. Neither phase segregation of the CeHfZrSnErOxsupport nor Pd sintering was observed under thermal treatment up to 900°C. The as-afforded Pd/CeHfZrSnErOxcatalyst exhibits good catalytic performance toward CO oxidation, outperforming Pd/CeO2of the same Pd loading, which highlights the inherent advantage of CeHfZrSnErOxas carrier support over traditional oxides.Graphical abstractDisplay OmittedHighlights•Single-phase, fluorite-structured high-entropy oxides nanocrystals was synthesized•An ultrasound-mediated co-precipitation strategy under ambient conditions was used•CeHfZrSnErOxexhibited high surface area and high oxygen vacancy concentration•Pd nanoclusters within the CeHfZrSnErOxarchitecture can be stabilizedChemistry; Inorganic materials; Materials science; Materials chemistry; Materials synthesis
