Sep 2023
Electrochemical reduction of CO2 (CO2R) through an electrochemical process is a strategy aimed at completing the carbon cycle for chemical production. Until now, this field has primarily concentrated on performing electrolysis on CO2 at standard atmospheric pressure. Nevertheless, in industrial settings, CO2 is typically pressurized during its capture, transportation, and storage, often existing in a dissolved state. We discovered that subjecting CO2 to a pressure of 50 bar shifts the CO2R pathways towards formate, a phenomenon consistently observed across commonly utilized CO2R catalysts. By creating techniques that can operate effectively under high pressures, including a quantifiable Raman spectroscopy approach while the reaction is ongoing, we have established a connection between the heightened preference for formate and the increased coverage of CO2 on the cathode surface. The collaboration between theoretical models and experimental data supports this mechanism and leads us to enhance the cathode surface of a copper electrode with a layer that resists protons, thereby amplifying the selective impact caused by pressure.
Dr. Xu Lu obtained his B.S. and Ph.D. degrees from Department of Mechanical Engineering, University of Hong Kong in 2012 and 2017, respectively. He was then trained as a postdoctoral fellow in the Department of Chemistry, Yale University. Dr. Lu joined KAUST in March, 2021 as an Assistant Professor of Mechanical Engineering. He is affiliated with Clean Combustion Research Center (CCRC) and KAUST Solar Center (KSC). Dr. Lu’s Low-carbon Energy Conversion and Storage (LECS) Lab focuses on electrochemical conversion of high-pressure CO2 conversion. So far, the LECS Lab has generated 2 U.S. provisional patents and research articles in Nature Communications (2), Angewandte Chemie, Chemical Engineering Journal, Joule etc. The LECS lab is also developing cutting-edge pilot-scale showcases with industrial partners such as ACWA Power and Aramco.