Creating high CO/CO2 selectivity and large CO working capacity through facile loading of Cu(I) species into an iron-based mesoporous metal-organic framework

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 348; pp. 135 - 142
• Main Authors: Kim, Ah-Reum, Yoon, Tae-Ung, Kim, Seung-Ik, Cho, Kanghee, Han, Sang-Sup, Bae, Youn-Sang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.09.2018
• Subjects: Carbon dioxide; Carbon monoxide; Gas separation; Metal-organic framework (MOF); Pi-complexation; Gas separation; Pi-complexation; Carbon monoxide; Metal-organic framework (MOF); Carbon dioxide
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2018.04.177

[Display omitted] •Cu(I) species were incorporated into an iron-based metal-organic framework (MOF) through a facile method.•The Cu(I)-loaded MOF exhibits high CO/CO2 selectivity and large CO working capacity simultaneously.•This MOF also exhibits very high CO/CH4 and CO/N2 selectivities.•This MOF shows good CO/CO2 separation and regeneration performance under realistic conditions. Achieving both high CO/CO2 selectivity and large CO working capacity in an adsorbent is very challenging. In this work, we have loaded Cu(II) species into large pores of an iron-based metal-organic framework (MOF) with a large surface area and reduced them into Cu(I) species under mild conditions by utilizing Fe(II) sites in the pores. Remarkably, the Cu(I)-incorporated MOF (0.9Cu@MIL-100) exhibits a high CO/CO2 selectivity (29 at 100 kPa) and a large CO working capacity (1.61 mmol/g at 10–100 kPa) simultaneously, which has not been observed for previously reported adsorbent materials. Moreover, 0.9Cu@MIL-100 also presents very high CO/CH4 and CO/N2 selectivities (87 and 677). Furthermore, breakthrough and cyclic adsorption-desorption experiments confirm that this material can efficiently separate CO/CO2 mixtures under dynamic mixture flow conditions and can be easily regenerated under mild conditions. This study provides a new strategy for developing adsorbents with both high CO/CO2 selectivities and large CO working capacities.