Inquiry for the multifunctional design of metal–organic frameworks: in situ equipping additional open metal sites (OMSs) inducing high CO₂ capture/conversion abilities

Abstract

On the basis of our conception of in-situ fabricating multifunctional metal-organic frameworks (MOFs), a binuclear Co-MOF [Co3(μ2-OH)(bpydc)(Htpim)2]·3NO3-·4MeOH·5DMA (1) (H2bpydc = (2,2’-bipyridine)-5,5’-dicarboxylic acid, Htpim = 2,4,5-tri(4-pyridyl)imidazole, DMA = N,N-dimethylacetamide) with additionally...

Porous functional metal–organic frameworks (MOFs) constructed from different N-heterocyclic carboxylic ligands for gas adsorption/separation

“…And it will further lead to the melting of glaciers, the rise of sea level and the occurrence of extreme weather (including floods, forest fires and droughts). [1][2][3] The Intergovernmental Panel on Climate Change (IPCC) indicates a warming of 1.5 °C in the future if the current trend continues, which will bring numerous hazards to marine and terrestrial ecosystems, food safety, human health, economic and social development and so on. 4,5 In short, the increasingly severe climate change situation is threatening the stability of the human social system and hindering the sustainable development of all mankind.…”

Contrasting-functionality-decked robust MOF for moisture-tolerant and variable-temperature CO2 adsorption with in-built urea group mediated mild condition cycloaddition

“…43,44 In this context, the major advantages of MOFs include: (1) open metal sites (OMSs) as Lewis acid sites, which provide electrostatic interactions with substrates, (2) heteroatom-bearing Lewis basic functionalities on organic struts, which confer favourable interactions with the reactants, and (3) optimized framework pores, which provide micro-reactor type environments to augment collisions between incoming CO 2 gas and epoxides to facilitate cycloaddition reaction. 40,[45][46][47][48][49][50][51][52] Nevertheless, non-redox CO 2 fixation in most MOFs often requires the use of hazardous solvents, harsh temperatures and/or pressures, and long reaction time. Additionally, the creation of high-density OMSs is hindered by thermo-chemical instability as well as lack of solvent-bound metal nodes, whilst pendent groups in organic struts not only block the micro-pores, but also lead to unwanted structures through coordination with metal ions.…”

Exploring the Effect of Different Secondary Building Units as Lewis Acid Sites in MOF Materials for the CO2 Cycloaddition Reaction

“…Among them, cycloaddition reactions of catalyzing CO 2 with epoxides into cyclic carbonates using MOF-based catalysts are one of the efficient CO 2 fixation methods. − On the one hand, the atom-economy reactions meet the requirement of green chemistry and play key roles in industry. On the other hand, active sites in MOFs such as open metal sites [OMSs, also Lewis acid sites (LASs)], , Lewis base sites (LBSs, the high election density groups), , and Brønsted acid sites (BASs, the protonated carboxyl groups) , endow them with significant priority than other materials in CO 2 fixations. Above advantages encouraged scientists to make in-depth studies on MOF catalytic effects and mechanisms in cycloaddition reactions.…”

“…36−41 On the one hand, the atom-economy reactions meet the requirement of green chemistry and play key roles in industry. On the other hand, active sites in MOFs such as open metal sites [OMSs, also Lewis acid sites (LASs)], 42,43 Lewis base sites (LBSs, the high election density groups), 44,45 and Brønsted acid sites (BASs, the protonated carboxyl groups) 46,47 advantages encouraged scientists to make in-depth studies on MOF catalytic effects and mechanisms in cycloaddition reactions. In our group's previous work, 48 four isomorphous Cu polyhedron-based MOFs were selected, and the roles of different LAS numbers and different LBS types in CO 2 cycloaddition reactions were systematically studied through a series of control experiments.…”