Bimetallic Copper-Silver Systems Supported on Natural Clinoptilolite: Long-Term Changes in Nanospecies’ Composition and Stability

Long-term changes in species of copper-silver bimetallic systems on natural clinoptilolite obtained by ion exchange Cu2+ and Ag+ then reduced at different temperatures were studied. Even after storage under ambient conditions, XRD UV-Vis diffuse reflectance spectra indicate the presence nanospecies larger particles copper silver. Scanning electron microscopy aged samples, highest temperature (450 °C) pristine sample for their preparation, also aged, showed silver with a size about 100 nm. They are formed initial ion-exchanged (without reduction) due to degradation ions. The larger; both samples they evenly distributed over surface. affects stability mechanism decomposition/oxidation species, this is higher systems. decomposition pattern recently includes formation smaller nanoparticles few-atomic clusters. This can occur, preceding complete oxidation Cu Quasicolloidal silver, which present fresh lower temperatures, transforms aging into Ag8 clusters, indicates these clinoptilolite.