Catalysts and systems for carbon dioxide electro-conversion

Abstract

Energy consumption is the primary cause of human-induced global warming, which contributes to 75.6% of global emissions. In this context, carbon dioxide (CO2) capture and conversion become the favored option via chemical, thermal, biological, electrochemical, and photochemical methods. Within these options, electrochemical carbon dioxide reduction reaction (CO2RR) powered by renewable electricity provides a sustainable avenue to convert CO2 into valuable fuels and achieve negative carbon emissions. Additionally, the conversion of intermittent renewable electricity into the chemicals is beneficial for storage and transport, avoiding energy waste and offering diverse energy usage scenarios. In this thesis, I focus on catalyst engineering and system design to achieve efficient CO2 electrolysis. I synthesized a coordination polymer catalyst Cu(OH)BTA with homogenized, single-site Cu active sites, which is found to be stable and efficient for CO2RR to C2+ products (Chapter 2). Then I extended the categories of coordination polymer catalysts with tunable Cu electronic states through ligand modification, revealing a volcano-shaped correlation between the binding strength of *CO intermediate and the C–C coupling efficiency (Chapter 3). To further overcome the carbonate issue in above alkaline CO2 electrolysis, I investigated the feasibility of alkali-metal-cation-free electrolytes for CO2RR, which employed non-metal polymeric cations as electrolytes and clarified the relationship between CO2RR performance and interfacial water structures (Chapter 4). This thesis explores catalyst engineering and system design for efficient CO2 electrolysis, focusing on the design of coordination polymer catalysts and the use of alkali-metal-cation-free electrolytes to enhance the selectivity and stability of CO2RR.