Electrochemical reduction of CO₂ to oxalic acid and other valuable C₂ chemicals

Sale, Halilu (2024) Electrochemical reduction of CO₂ to oxalic acid and other valuable C₂ chemicals. PhD thesis, University of Glasgow.

Abstract

In recent years, there has been a growing interest and widespread adoption of electrochemical methods to address many of the energy and environmental challenges we encounter in modern society. This electrochemical approach encompasses a variety of highly adaptable techniques that often eliminate the need for harmful chemicals and extreme temperatures, aiming to offer an alternative to fossil-based compounds. In this thesis, we explore how electrochemistry can be harnessed for the development of a sustainable process based on electro-reduction. By showcasing the versatility of these techniques, our work covers a broad spectrum of approaches and analytical methods, with potential implications ranging from providing alternative pathways for industrially relevant chemical production to reducing reliance on fossil resources.

Chapter 1 introduces the electrochemical reduction of CO2 to oxalic acid and other C2 chemicals. It explains the fundamental concepts of this approach, discusses the parameters affecting its efficacy, and provides an extensive account of its application in previous and recent years. Chapter 2 delves into the experimental techniques underpinning the research in this thesis.

Chapter 3 details the application of benzonitrile as a catalyst to enhance the electrochemical reduction of CO2 to oxalic acid on the Pb electrode in propylene carbonate. Our findings indicate that the inclusion of benzonitrile in the electrolyte enhances the faradaic and reaction yields of oxalate/oxalic acid production, along with an improved area-normalized rate of formation. This achievement sets a record rate for oxalate/oxalic acid formation.

Chapter 4 explores the electrochemical reduction of oxalic acid to glyoxylic and glycolic acids on a Ti-based electrode. Our findings reveal that the direct electrochemical reduction of oxalic acid to these compounds of industrial importance (glyoxylic and glycolic acids) can be achieved with a high yield at room temperature, facilitated by the native oxides of titanium (Ti/TixOy).

Chapter 5 highlights the combined impacts of ultrasound and electrochemistry in the sonoelectrochemical reduction of CO2 on a copper electrode, aiming to produce valuable products. The findings reveal a compelling outcome, which tackles the issue of bubble formation on the electrode surface and mitigates charge transfer resistance by amplifying the mass transport of electroactive species through acoustic streaming and cavitation phenomena.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Supported by funding from the Petroleum Technology Development Fund (PTDF).
• Subjects: Q Science > QD Chemistry
• Colleges/Schools: College of Science and Engineering > School of Chemistry
• Supervisor's Name: Symes, Professor Mark
• Date of Award: 2024
• Depositing User: Theses Team
• Unique ID: glathesis:2024-84422
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 01 Jul 2024 15:17
• Last Modified: 01 Jul 2024 15:17
• Thesis DOI: 10.5525/gla.thesis.84422
• URI: https://theses.gla.ac.uk/id/eprint/84422

Related URLs

• Article DOI
• Data DOI
• Data DOI
• Article DOI