Simultaneous adsorption of SO₂ and CO₂ in an Ni(bdc)(ted)_0.5 metal-organic framework

The metal-organic framework Ni(bdc)(ted)_0.5 is a promising material for simultaneous capture of harmful gases such as SO₂ and CO₂. We found that SO₂ performs much better than CO₂ during adsorption, and the lack of physical insight was clarified through detailed analyses of the electronic structures obtained from density functional theory calculations. Our results showed that strong interactions of the d band of Ni atoms with the valence states (2n, 3n, and 4n) of SO₂ but almost not with those of CO₂ are the main reasons. Our finding is useful for the rational design of new metal-organic frameworks with suitable interactions for the simultaneous capture of not only SO₂ and CO₂ but also other gases.