Tailoring Metal–Organic Frameworks for CO₂ Capture: The Amino Effect

Abstract

Carbon dioxide capture from processes is one of the strategies adopted to decrease anthropogenic greenhouse gas emissions. To lower the cost associated with the regeneration of amine-based scrubber systems, one of the envisaged strategies is the grafting of amines onto high-surface-area supports and, in particular, onto metal-organic frameworks (MOFs). In this study, the interaction between CO(2) and aliphatic and aromatic amines has been characterized by quantum mechanical methods (MP2), focusing attention both on species already reported in MOFs and on new amine-based linkers, to inspire the rational synthesis of new high-capacity MOFs. The calculations highlight binding-site requisites and indicate that CO(2) vibrations are independent of the adsorption energy and monitoring them in probe-molecule experiments is not a suitable marker of efficient adsorption.

Ab Initio Study of the Adsorption of CO2 on Functionalized Benzenes

“…Amine increases the CO 2 /CH 4 separation factor (from 5 to 60) compared with non-functionalized MIL-53. As has been noted in previous studies, [55,56] dispersion forces and electrostatic interactions contribute almost equally to the binding energy of CO 2 and, in some cases, dispersion forces have a more dominant role in the binding energy of the molecular systems. [29,40] Open metal sites have been also studied for CO 2 capture and separation.…”

Magnesium-based systems for carbon dioxide capture, storage and recycling: from leaves to synthetic nanostructured materials

“…23 A shift in the mode to 2338 cm -1 has been estimated for the unperturbed molecule in microporous materials 15 due to confinement. 17 If chemical bonded species are formed, signals in the 1800-800 cm -1 region are observed, the position of which bands is indicative not only of the nature of the formed species but also of the geometry of coordination. 12,22 A comprehensive review of the characterization by infrared 20 spectroscopy of CO 2 surface species on oxide surfaces is reported in Ref.…”

“…This effect was expected because of the low pressure considered and the importance of dispersion forces in CO 2 50 interaction with material surfaces, also in presence of highly polarizing sites. 17,144,145 The potential of two opposite pore walls is additional only up to a limit pore dimension. A glance to Figure 9c seems to indicate that whereas for IRMOF-74-IIb (light blue triangles) such an effect is still present, in IRMOF-74-III 55 (light blue stars) it is completely lost.…”

Fast carbon dioxide recycling by reaction with γ-Mg(BH4)2

“…In fact, the proximity to the cation of hydrogen atoms, negatively charged, gives rise to one Lewis basic-acid couple per Mg atom: these couples are well known to be the most suitable ones to enlarge the affinity of unreactive CO 2 toward surfaces. 11,12 For example, late transition metal (Ni,Rh) hydrides 13,14 instantaneously catalyse the transformation of CO 2 in formiate in the presence of borane. Nickel hydride with a diphosphinite-based ligand is an high efficient catalyst for the reduction of CO 2 with catecholborane, and the hydrolysis of the resulting methoxyboryl species produces CH 3 OH in good yield.…”