Multicomponent Adsorption Mechanism of CO 2 , SO 2 , and NO from Flue Gases on Metal-Doped Porous Carbon

Synergistic reduction of pollution and carbon emissions is a critical pathway for achieving the deep purification of flue gases. Ce- and Cu-loaded porous carbons were synthesized, and the coadsorption capacity and adsorption mechanism of CO 2, SO 2, and NO were studied. At 25 °C and 1 bar, the adsorption capacities of Ce-loaded porous carbon are 3.42, 1.17, and 2.80 mmol/g for CO 2, SO 2, and NO, respectively. The presence of SO 2 inhibits CO 2 and NO adsorption, whereas CO 2 promotes SO 2 adsorption but suppresses NO adsorption in the multicomponent coadsorption process. Conversely, NO enhances SO 2 adsorption while suppressing CO 2 adsorption. The performance of Ce-loaded porous carbon significantly decreased during multicomponent adsorption, with NO and CO 2 adsorption being notably suppressed, compared to separation adsorption. Mechanism studies revealed that CO 2 adsorption primarily follows a physical process, whereas SO 2 adsorption involves oxidation at metal active sites to form SO 3, ultimately generating sulfates. NO adsorption occurs via oxygen-assisted chemisorption on metal sites, forming adsorbed NO* species that are further converted to NO 2 . These findings provide insights into the design of multifunctional adsorbents for synergistic air pollution and carbon control in flue gases.