title: Enhanced Carbon Dioxide Capture from Landfill Gas Using Bifunctionalized Benzimidazole-Linked Polymers.
abstract: Tuning the binding affinity of small gases and their selective uptake by porous adsorbents are vital for effective CO2 removal from gas mixtures for environmental protection and fuel upgrading. In this study, an amine-functionalized benzimidazole-linked polymer (BILP-6-NH2) was synthesized by a combination of pre- and postsynthetic modification techniques in two steps. Presynthetic incorporation of nitro groups resulted in stoichiometric functionalization (1 nitro/phenyl) in addition to noninvasive functionalization, where more than 80% of the surface area maintained compared to BILP-6. Experimental studies presented enhanced CO2 uptake and CO2/CH4 selectivity in BILP-6-NH2 compared to BILP-6, which are governed by the synergetic effect of benzimidazole and amine moieties. DFT calculations were used to understand the interaction modes of CO2 with BILP-6-NH2 and confirmed the efficacy of amine groups. Encouraged by the enhanced uptake and selectivity in BILP-6-NH2, we have evaluated its performance in landfill gas separation under vacuum swing adsorption (VSA) settings, which resulted in very promising working capacity and sorbent selection parameters outperforming most of the best solid adsorbent in the literature.
authors.affiliation: Department of Chemistry, Virginia Commonwealth University , 1001 West Main Street, Richmond, Virginia 23284-2006, United States.
authors.forename: Timur
authors.initials: T
authors.lastname: Islamoglu
authors.affiliation: Department of Physics, Virginia Commonwealth University , 701 West Grace Street, Richmond, Virginia 23284-2006, United States.
authors.forename: Swayamprabha
authors.initials: S
authors.lastname: Behera
authors.affiliation: Department of Chemistry, Virginia Commonwealth University , 1001 West Main Street, Richmond, Virginia 23284-2006, United States.
authors.forename: Zafer
authors.initials: Z
authors.lastname: Kahveci
authors.affiliation: Department of Chemistry, Virginia Commonwealth University , 1001 West Main Street, Richmond, Virginia 23284-2006, United States.
authors.forename: Tsemre-Dingel
authors.initials: TD
authors.lastname: Tessema
authors.affiliation: Department of Physics, Virginia Commonwealth University , 701 West Grace Street, Richmond, Virginia 23284-2006, United States.
authors.forename: Puru
authors.initials: P
authors.lastname: Jena
authors.affiliation: Department of Chemistry, Virginia Commonwealth University , 1001 West Main Street, Richmond, Virginia 23284-2006, United States.
authors.forename: Hani M
authors.initials: HM
authors.lastname: El-Kaderi
keywords: CO2 capture; benzimidazole-linked polymers; functionalization of porous organic polymers; landfill gas purification; sorbent selection parameters