Supramolecular chemistry for carbon dioxide capture

The ever-increasing global warming and environmental deterioration call for carbon emission reduction, however current carbon capture technologies are not fairly efficient to come into effect, considering their high energy-consumption and economic-cost. This review renews supramolecular chemistry for carbon dioxide capture, in which specific supramolecular chemical interaction between absorbent host and carbon dioxide guest guarantees the high selectivity and low binding energy of non-chemical bonds. Supramolecular interactions enable easy carbon dioxide release and absorbent regeneration for cycling. This review is outlined starting with introducing the background of carbon capture, utilization and storage (CCUS). In this context, we are discussing the difficulties faced in emission reduction, particularly due to the high energy demands and economic costs of extracting carbon dioxide (CO₂) from flue gas. Afterwards, the fundamentals and mechanism of supramolecular chemistry are presented followed by discussing the advantages and limitations of CO₂ hydrates as the first generation of supramolecular chemical CO₂ capture materials. The typical supramolecular materials, including calixarenes, pillararenes etc., are demonstrated while discussing the CO₂ diffusion behaviors in the supramolecules lattice for capture. Newly developed the third-generation supramolecular hydrogen-bond ionic framework (HIF) materials are introduced and elaborated. Using HIF materials, the reversible CO₂ capture and release could be achieved at mild conditions, and thus shows great promise for practical CO₂ capture from flue gas in industry. At the end of review, we discuss the potential industrial applications of supramolecular chemistry for carbon capture, proposing HIF materials with their tunable structures as a promising candidate for improving CO₂ capture efficiency aiming to relief both energy consumption and economic cost burdens.