Incorporation of Cu(I) Sites into Zeolite via a Controllable Reduction Strategy for Ethylene/Ethane Separation

The development of effective adsorbents for efficient separation of ethylene (C₂H₄) and ethane (C₂H₆) is crucial for the petrochemical sector, yet this is still difficult because of their comparable molecule sizes and physical characteristics. Cu(I) could generate π-complexes with molecules containing unsaturated bonds, enabling Cu(I)-based adsorbents to selectively and efficiently separate C₂H₄ from C₂H₆. However, the traditional autoreduction method typically requires extreme temperatures (≥700 °C) to convert Cu(II) to Cu(I), leading to high energy consumption. In this study, we present a controllable reduction strategy that employs methanol as the reductant to efficiently and controllably convert Cu(II) in Y zeolite to Cu(I). With this approach, Cu(I) sites could be formed under a modest temperature of 200 °C. Due to the generated Cu(I) sites, the C₂H₄ uptake for Cu(I)-Y reaches 3.85 mmol/g and the C₂H₄/C₂H₆ selectivity is 19.21. This performance surpasses those of benchmark adsorbents, including CuX (2.31 mmol/g, 1.06), Cu(I)-doped mesoporous carbon MC-Cu-2 (1.94 mmol/g, 4.00), and Cu⁺@MIL-101 (2.46 mmol/g, 14.00).