Zeolite X Loaded with Ag+ as a Slow Ethylene-Releasing Nanoporous Material to Suppress Potato Sprouting

Nanostructured silver-exchanged zeolites (Ag⁺-exchanged zeolites) have been widely studied for ethylene (C₂H₄) removal from space and separation from a mixture. However, the controlled release of C₂H₄ from Ag⁺-exchanged zeolites has received little attention. In this study, we propose a novel application of Ag⁺-zeolite X as a C₂H₄-releasing nanoporous material to suppress potato sprouting. The adsorption and release behavior of C₂H₄ over a series of Ag⁺-exchanged zeolites with different zeolite framework topology and Ag loadings were systematically investigated. The characteristics of zeolites significantly influenced nature of introduced Ag species, which in turn affected the adsorption and release behavior of C₂H₄. In zeolites with high Ag loadings, Ag species tend to aggregate into large Ag clusters or metallic Ag⁰ nanoparticles, which do not work as C₂H₄ binding sites. Among the Ag⁺-exchanged zeolites studied, Ag₃₆-X, which is a zeolite X with silver ion-exchange rate of 36%, showed high C₂H₄ adsorption capacities and sustained C₂H₄ release characteristics. The application of Ag₃₆-X in potato packaging demonstrated superior sprout inhibition performance compared to a commercial C₂H₄ release agent, highlighting the promise of Ag-loaded zeolites as tunable C₂H₄ release nanoporous materials for postharvest applications.