Low-temperature fabrication of Cu(I) sites in zeolites by using a vapor-induced reduction strategy

Due to their versatility, nontoxicity, and low cost, Cu(I) ion exchanged zeolites are of great interest for various applications. Despite many attempts, the development of an efficient, controllable, and energy-saving approach to fabricate Cu(I) sites in zeolites remains an open question. In this study, a strategy was developed to convert Cu(II) in zeolites to Cu(I) selectively using vapor-induced reduction (VIR) with methanol. The methanol vapors generated at elevated temperatures diffuse into the pores of zeolites and interact with Cu(II) ions, leading to the formation of Cu(I). This strategy allows the construction of Cu(I) sites at low temperatures and avoids the formation of Cu(0). Moreover, the obtained material exhibits excellent performance in the adsorptive separation of propylene/propane with regard to both capacity and selectivity, which is obviously superior to the material prepared by the conventional autoreduction method as well as using various typical adsorbents.