17 O NMR Spectroscopy Reveals CO 2 Speciation and Dynamics in Hydroxide‐Based Carbon Capture Materials
Year: 2024
Type: article
Abstract: Carbon dioxide capture technologies are set to play a vital role in mitigating the current climate crisis. Solid‐state 17 O NMR spectroscopy can provide key mechanistic insights that are crucial to effective sorbent development. In this work, we present the fundamental aspects and complexities for the study of hydroxide‐based CO 2 capture systems by 17 O NMR. We perform static density functional theory (DFT) NMR calculations to assign peaks for general hydroxide CO 2 capture products, finding that 17 O NMR can readily distinguish bicarbonate, carbonate and water species. However, in application to CO 2 binding in two test case hydroxide‐functionalised metal‐organic frameworks (MOFs) – MFU‐4l and KHCO 3 ‐cyclodextrin‐MOF, we find that a dynamic treatment is necessary to obtain agreement between computational and experimental spectra. We therefore introduce a workflow that leverages machine‐learning force fields to capture dynamics across multiple chemical exchange regimes, providing a significant improvement on static DFT predictions. In MFU‐4l, we parameterise a two‐component dynamic motion of the bicarbonate motif involving a rapid carbonyl seesaw motion and intermediate hydroxyl proton hopping. For KHCO 3 ‐CD‐MOF, we combined experimental and modelling approaches to propose a new mixed carbonate‐bicarbonate binding mechanism and thus, we open new avenues for the study and modelling of hydroxide‐based CO 2 capture materials by 17 O NMR.
Source: ChemPhysChem
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
SDG: Climate action
Open Access status: hybrid
Estimated APC paid: $4,330
Funders: National Science Foundation, U.S. Department of Energy, UK Research and Innovation, Advantage West Midlands, Leverhulme Trust, University of Warwick, Office of Science, Engineering and Physical Sciences Research Council, Biotechnology and Biological Sciences Research Council, Science and Technology Facilities Council, Jesus College, University of Cambridge, European Regional Development Fund, Division of Chemistry, Basic Energy Sciences
Awards: G1775824767, G2290622660, G2907406413, EPSRC Core Equipment Award 2022/23, G3716179185, The UK Car-Parrinello HEC Consortium, G4296573280, EPSRC Centre for Doctoral Training in Automated Chemical Synthesis Enabled by Digital Molecular Technologies, CAREER: Using Metal-Organic Frameworks to Harness Molecular Catalysts for Selective C-H Functionalization, G581313191, G6060081955, The UK High-Field Solid-State NMR National Research Facility, G644095751, NEW MOLECULAR MECHANISMS FOR GREENHOUSE GAS CAPTURE IN METAL–ORGANIC FRAMEWORKS: CARBON DIOXIDE AND BEYOND, Cambridge Service for Data Driven Discovery (CSD3) - A National Data Intensive Science Cloud for Converged Simulation, AI & Analytics, Support for the UKCP consortium, G7633989764, Solid-State NMR at 1.0 GHz: A World-Leading UK Facility to Deliver Advances in Chemistry, Biology and Materials Science, G8551587572, G8845531966, G955821083
OpenAlex ID: W4404567174