Mn-doped Y zeolite for ethylene/acetylene separation

Physical adsorptive removing the trace acetylene (C₂H₂) from the ethene/acetylene (C₂H₂/C₂H₄) mixture is a promising method for the C₂H₄ purification, but simultaneously improving the capacity and selectivity of adsorbent remains a challenge. Herein, we reported the fabrication of Mn-doped FAU zeolite (Mn-Y) and the Mn substitution-derived enhancement in the C₂H₂/C₂H₄ separation. Mn-Y was directly synthesized by acid co-hydrolysis route, and the embedding of Mn species into framework was demonstrated by X-ray absorption fine structure analysis, UV–vis spectra, and structure refinement against the high-resolution powder X-ray diffraction pattern. Mn-Y exhibited higher C₂H₂ uptakes (5.44 mmol g⁻¹) while lower C₂H₄ uptakes (3.99 mmol g⁻¹) than Y, with a selectivity of 15.96. Column breakthrough experiments demonstrated that Mn-Y exhibited higher dynamic separation efficiency than Y, producing polymer-grade C₂H₄ with a productivity of 556 L kg⁻¹. Structure refinement results indicated that Mn-doping regulates the affinity for C₂H₂ and C₂H₄, attributable to the enriched electron density of framework.