Role of Hydrogen‐Bond Interactions in CO2 Capture by Wet Phosphonium Formate Ionic Liquid: A Raman Spectroscopic Study. Issue 13 (24th April 2018)

• Record Type: Journal Article
• Authors: Yasaka, Yoshiro; Saito, Yuma; Kimura, Yoshifumi
• Is Part Of: Chemphyschem. Volume 19:Issue 13(2018)
• Page Start: 1674
• Page End: 1682
• Publication Date: 2018-04-24
• Subjects: CO2 capture -- formate -- ionic liquids -- Raman spectroscopy -- reaction mechanism; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201701324
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: The mechanism of CO2 absorption by a formate ionic liquid, [P4444 ]HCOO, was studied by Raman spectroscopy. The band area for the symmetric CO2 stretching of the formate anion linearly decreases with the CO2 loading. From the slope of the decrease, 1 : 1 stoichiometry is proven between CO2 and the formate anion. The result favors the mechanism we proposed in a preceding work [J. Chem. Eng. Data 61, 837 (2016)]: HCOO − +CO2 +H2 O→HCOOH+HCO3 − →[HCOOH…HCO3 − ]. Further support for the mechanism is obtained by the observation of antisymmetric vibration of CO for the proposed hydrogen‐bonded complex between HCOOH and HCO3 − . The bands appeared as a doublet (1677 and 1730 cm −1 ) as this complex has two carbonyl groups. Based on DFT calculations, the [HCOOH…HCO3 − ] complex is supposed to be the most abundant form of chemisorbed CO2 . Abstract : The mechanism of CO2 absorption by a formate ionic liquid, [P4444 ]HCOO, is studied by Raman spectroscopy. The band area for the symmetric CO2 stretching of the formate anion linearly decreases with the CO2 loading. From the slope of the decrease, a 1 : 1 stoichiometry is proven between CO2 and the formate anion.