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 for separation from mixtures. 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 slow C2H4-releasing nanoporous material to suppress potato sprouting. The adsorption and release behaviors of C2H4 over a series of Ag+-exchanged zeolites with different zeolite framework topologies and Ag loadings were systematically investigated. The characteristics of the zeolites significantly influenced the nature of the 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 zeolite X with a 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 potential of Ag-loaded zeolites as tunable C2H4 release nanoporous materials for postharvest applications.