Sulfate-Pillared Adsorbent for Efficient Acetylene Separation from Carbon Dioxide and Ethylene

Abstract

The effective separation of acetylene (C2H2) from carbon dioxide (CO2) and ethylene (C2H4) presents considerable challenges in the petrochemical industry. In this work, we report a novel sulfate-pillared (SO42–) ultra-microporous material, denoted as SOFOUR-DPDS-Ni (SOFOUR = SO42–, 4-DPDS = 4,4′-dipyridyldisulfide), for efficient C2H2 capture from both CO2 and C2H4. The sulfate pillars play a crucial role in inducing robust negative electrostatic potentials within the intralayer cavities and interlayer channels, thereby facilitating the selective recognition of C2H2. As a result, SOFOUR-DPDS-Ni demonstrates a remarkable C2H2 adsorption capacity of 1.60 mmol g–1 at 0.01 bar, an exceptional selectivity of 174 for the 50/50 C2H2/CO2 mixture, and a high selectivity of 65 for the 1/99 C2H2/C2H4 mixture. These impressive metrics position SOFOUR-DPDS-Ni as a promising adsorbent for benchmark C2H2 separations. Dynamic breakthrough experiments validate its outstanding performance in separating C2H2 from both the CO2 and C2H4 mixtures. Computational simulations reveal the strong interactions between C2H2 and sulfate pillars, shedding light on the underlying mechanisms driving the adsorption process.