Relevance of hydrogen bonding in CO₂ capture enhancement within InOF-1: an energy and vibrational analysis

The enhancement of CO₂ capture due to the confinement of polar molecules within InOF-1 was previously demonstrated. In particular, the presence of MeOH produced 1.30-fold increase in the total CO₂ capture. This was explained before with the presence of hydrogen bonds. However, a detailed analysis of the hydrogen bonds among μ₂-OH functional groups, MeOH molecules and CO₂ molecules was not elucidated; moreover, the possible mechanisms that could explain the enhancement of the capture were also not explained. In this investigation, the density functional theory (DFT) periodic calculations and experimental in situ DRIFTS results allowed us to postulate four plausible CO₂ adsorption mechanisms for MeOH-functionalised InOF-1, which described the hydrogen bonds and rationalised the nature of the CO₂ capture enhancement.