Organic Electrochemistry for CO2 Capture
Molecular interactions between electrochemically reduced flavins and CO2
The third strand of my PhD explored the electrochemistry of redox-active organic molecules — quinones and flavins — for potential use in CO2 capture and organic-based energy storage.
I examined the electrochemical reduction of riboflavin (vitamin B2) in dimethyl sulfoxide under a CO2 atmosphere, comparing the behavior to reduction under argon. Using variable-scan-rate cyclic voltammetry combined with controlled potential electrolysis, UV–Vis, and EPR spectroscopy, I found that CO2 shifts the overall reduction from a one-electron to a two-electron process, driven by riboflavin–CO2 molecular interactions that lower the formal reduction potential of the flavin radical anion 1.
Digital simulation modeling of the voltammetric data allowed extraction of thermodynamic and kinetic parameters for the proposed mechanism — a multi-step pathway involving proton-coupled electron transfer, diamagnetic anions, radical anions, and neutral radical intermediates, along with evidence of a long-lived riboflavin–CO2 complex in solution.
These findings contribute to the broader search for organic-molecule-based strategies for carbon capture and utilization, complementing more conventional inorganic and materials-based approaches.
My role: Lead researcher — electrochemical and spectroscopic experiments, mechanistic analysis, and manuscript preparation, under the supervision of Assoc Prof Richard D. Webster (NTU).