(67c) Exploring How Collective Ionic Assembly Influences Electrochemical Carbon Dioxide Upgrading
AIChE Annual Meeting
2021
2021 Annual Meeting
Catalysis and Reaction Engineering Division
Electrochemical CO2 Conversion I
Monday, November 8, 2021 - 8:36am to 8:54am
Electrochemical reduction of CO2 to CO, CH4, and other value-added products provides compelling opportunities to realize a closed anthropogenic carbon cycle. While increasingly demonstrated in lab-scale electrolyzers, a critical roadblock facing the design of industrial processes is a poor understanding of how molecular assembly at electrode-electrolyte interfaces contributes to catalytic activity. Over the last decade, ionic liquids have emerged as promising CO2 reduction electrolytes, since low overpotentials and enhanced product selectivity has been observed for several classes of ionic liquids. However, the mechanisms of ionic liquid-mediated catalysis remain subject to ongoing discussion. Here, we present our research on tuning the collective assembly of ionic liquids to understand the mechanism of ionic liquid-mediated CO2 reduction at silver, copper, and carbon electrodes. By changing ionic liquid structures, concentrations, and solvent environments, we reveal unexpected non-monotonic scaling relationships between structure, concentration, and reactivity. Notably, these findings point to collective assembly as a key factor underpinning structure-reactivity relationships for CO2 electro-reduction. To highlight the impact of this concept, we will show how our findings help resolve a mechanistic puzzle in the ionic liquids electrocatalysis community and suggest new strategies for controlling the performance of CO2 electrochemical upgrading.