Near-ambient pressure XPS and NEXAFS study of a superbasic ionic liquid with CO2

DOI: 10.1021/acs.jpcc.1c05738

Authors: Jordan Cole (University of Central Lancashire) , Zoe Henderson (University of Central Lancashire) , Andrew G. Thomas (University of Manchester) , Claudia L. Compeán-González (University of Manchester) , Adam Greer (University of Manchester) , Christopher Hardacre (University of Manchester) , Federica Venturini (Diamond Light Source) , Wilson Quevedo Garzon (Diamond Light Source) , Pilar Ferrer (Diamond Light Source) , David C. Grinter (Diamond Light Source) , Georg Held (Diamond Light Source) , Karen L. Syres (University of Central Lancashire)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: The Journal Of Physical Chemistry C

State: Published (Approved)
Published: October 2021
Diamond Proposal Number(s): 20532

Abstract: In situ photoemission and near-edge X-ray absorption fine structure (NEXAFS) techniques have been used to study the interaction of CO2 with an ionic liquid thin film. A thin film of the superbasic ionic liquid (SBIL) trihexyltetradecylphosphonium benzimidazolide ([P66614][benzim]) was prepared on a rutile TiO2 (110) surface and exposed to CO2 at near-ambient pressures. NEXAFS measurements combined with density functional theory calculations indicate a realignment of [benzim]− anions from 27° from the surface normal to 54° upon exposure to CO2. Angle-resolved X-ray photoelectron spectroscopy (AR-XPS) shows evidence of irreversible CO2 absorption in thin films of [P66614][benzim] and a greater concentration of CO2-reacted anions in the deeper layers. These results give a new perspective on CO2 uptake in ionic liquids and fundamental interactions at the liquid–gas interface. Understanding this interfacial behavior is important for developing ILs for gas capture applications and may influence the performance of other IL-based technologies.

Journal Keywords: Salts; X-ray absorption near edge spectroscopy; Thin films; Anions; Solvents

Diamond Keywords: Carbon Capture and Storage (CCS)

Subject Areas: Physics, Chemistry


Instruments: B07-C-Versatile Soft X-ray beamline: Ambient Pressure XPS and NEXAFS

Added On: 14/10/2021 09:18

Discipline Tags:

Physical Chemistry Earth Sciences & Environment Climate Change Physics Surfaces interfaces and thin films Chemistry

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) X-ray Photoelectron Spectroscopy (XPS) Near Edge X-ray Absorption Fine Structures (NEXAFS) Near Ambient Pressure XPS (NAP-XPS)