Student Inorganic Chemistry Seminar with Sophia Weng (MIT- Surendranath Group)

, 4-370

Molecular level insights into the design of electrolyte cations for electrochemical CO2 reductionAbstract: The direct interconversion of electrical and chemical energy is essential for a sustainable energy economy. Electrochemical CO2 reduction (CO2RR) and hydrogen evolution (HER) are two examples of important fuel-forming reactions which could enable excess electrical energy to be stored in the form of chemical bonds. Given various technoeconomic considerations, these reactions would ideally be run under alkaline conditions in which the catalyst is directly in contact with a hydroxide-conducting polymer bearing charged functional groups. However, while many groups in recent years have focused on the development of new polymers and formulations for such applications, little is known about how the cationic organic functional groups in these polymeric materials affect the interfacial reaction environment, especially since a large excess of alkali metal salts is often added in these studies. Herein, we develop a method for studying water-soluble organic cations as bulk supporting electrolyte, with the goal of understanding the intrinsic ability of organic cations to alter the rates of CO2RR and HER. We demonstrate that, contrary to prior claims in the literature, organic cations are capable of supporting CO2RR in the absence of alkali metal cations. With this finding in hand, we then study the effects of organic supporting electrolyte cation structure on the rates of CO2RR and HER. These results are critical to enabling rational molecular-level design of new ionomers for zero-gap alkaline electrolysis devices.Refreshments will be served outside of 4-370 at 4:00PM.