Surface-Modified CeO₂-Octahedron-Supported Pt Nanoparticles as Ethylene Scavengers for Fruit Preservation

Catalytic oxidation of ethylene associated with the preservation of fruits and vegetables (F&V) at low temperatures remains challenging. To address this issue, CeO2-octahedron-supported Pt catalysts were synthesized and modified by capacitively coupled plasma for efficient catalytic oxidation of C2H4. After the plasma treatment, CeO2 with rich oxygen vacancies was created, which acted as a support to facilitate the regulation of the size and dispersion of Pt nanoparticles. Compared with Pt/pristine CeO2, the Pt/plasma-modified CeO2 catalyst (Pt/CeO2-P) showed significantly higher reactivity. More than 99.9% of ethylene conversion induced by Pt/CeO2-P could be sustained longer than 50 h at 25 °C, and 30 min even at 0 °C. Thus, Pt/CeO2 interface engineering by plasma modification technology is particularly promising for low-temperature catalytic oxidation of ethylene. Moreover, a comprehensive characterization was conducted to elucidate the reaction pathway and oxidation mechanism. From the preservation test using bananas as fruit samples, it was found that Pt/CeO2-P delayed postharvest deterioration and ripening of bananas due to the excellent ethylene scavenging effect created by the catalyst, thus demonstrating the great potential applications in F&V preservation.