A first-principles study of the selective adsorption of CO from shift reaction gas by MN4C20

This study employs density functional theory (DFT) to investigate a novel two-dimensional metalloporphyrin polymer, MN 4 C 20 , for selective CO capture from water-gas shift reaction tail gas (CO, CO 2 , H 2 , CH 4 ). Results show that CO adsorbs via a synergistic σ-π interaction at the metal center. Among the series, Sc-, Ti-, V-, and FeN 4 C 20 exhibit strong chemisorption, while Cr-, Fe-, and CoN 4 C 20 demonstrate high CO selectivity within the 320–697 K range, with only weak adsorption for CO 2 , H 2 , and CH 4 . Compared to molecular MPs, the 2D MN 4 C 20 framework offers more moderate adsorption strength and superior cycling stability, presenting a promising strategy for efficient CO separation. • Studies 2D material MN 4 C 20 for capturing carbon monoxide from water-gas shift reaction tail gas. • Identifies specific materials that strongly and selectively grab CO molecules. • Shows these materials allow easy release of CO for reuse when heated. • Suggests these materials are more stable and reusable than older options.