Nanomaterials Design for the Efficient Electrochemical Reduction of Carbon Dioxide
With increasing concern over climate change and environmentally friendly technologies, carbon dioxide (CO2) conversion technologies have developed significant interest for using CO2 as a green, inexpensive carbon source for the production of value-added chemicals and fuels. Electrochemical reduction of CO2 has advantages such as being able to control the reaction by adjusting the reaction conditions and renewable energy can be used to drive the reaction. However, challenges of slow kinetics and low efficiency need to be overcome before the technology becomes viable for industrial use. This thesis demonstrates facile approaches to the design of novel nanomaterials for the electrochemical reduction of CO2. CuAu nanodendrites fabricated via electrodeposition on Ti have shown to be a good catalyst for the production of syngas with tunable ratios of H2 to CO depending on the reduction potential. A reduction potential of −0.86 V (vs. RHE) allows for a ratio of H2 to CO of 1.915, which is close to the ideal ratio of 2 for syngas in methanol production. Nanoporous Ag wire electrodes were fabricated by an electrochemical Zn alloying/dealloying method. The produced nanoporous Ag electrodes demonstrated high surface areas for the reduction of CO2. It was determined that CO2 reduction was limited by mass transfer for the nanoporous Ag and that flow cells designed to improve mass transfer limitations would result in significantly higher catalytic activities.