MOF-derived bimetallic coordination polymer@cobalt-aluminum layered double hydroxide for highly selective CO 2 adsorption: Experiments, mechanisms

• Published in: Journal of colloid and interface science 2023-09, Vol.645, p.784
• Main Authors: Huang, Zhen, Ying, Liangri, Gong, Fengchun, Liu, Shule, Wang, Weilong, Ding, Jing
• Format: Article
• Language: English
• ISSN: 1095-7103

Selective capture of CO is one of the most effective strategies for combating the greenhouse effect. In this study, we report the synthesis of a novel adsorbent-an amine-based cobalt-aluminum layered hydroxide with a hafnium/titanium metal coordination polymer (denoted as Co-Al-LDH@Hf/Ti-MCP-AS)-through the derivatization of metal-organic frameworks (MOFs) for selective CO adsorption and separation. Co-Al-LDH@Hf/Ti-MCP-AS achieved the maximum CO adsorption capacity of 2.57 mmol g at 25 °C and 0.1 MPa. The adsorption behavior followed the pseudo-second-order kinetics and Freundlich isotherm models, indicating that chemisorption occurs on a non-homogeneous surface. Co-Al-LDH@Hf/Ti-MCP-AS also exhibited selective CO adsorption in CO /N and excellent stability over six adsorption-desorption cycles. An in-depth analysis of the adsorption mechanism through X-ray photoelectron spectroscopy and density-functional theory and frontier molecular orbital calculations revealed that adsorption occurs through acid-base interactions between amine functional groups and CO and that the tertiary amines (N3) have the highest affinity toward CO . Our study provides a novel strategy for designing high-performance adsorbents for CO adsorption and separation.