Predictive energetic tuning of C-Nucleophiles for the electrochemical capture of carbon dioxide

Predictive energetic tuning of quinoid O-nucleophiles for the electrochemical capture of carbon dioxide

“…As previously observed for a family of C-nucleophiles, 10 we now report a linear correlation between the potential required to generate quinone dianions and their free energy of CO 2 binding. Unlike the relatively simple electrogenerated C-nucleophiles of our previous report, the doubly reduced quinones exhibit variable stoichiometric coefficients when binding to CO 2 .…”

“…With eqn (10) in hand, values for DE 1 2 and [CO 2 ] were calculated for each quinone for CVs taken under 5%, 30%, and 100% CO 2 (Fig. 2).…”

“…8 In a related recent report, several quinones were categorized as strong vs. medium vs. weak binders of CO 2 . 9 In recent work from our group, 10 we identified an empirical linear correlation between the reduction potential necessary for the generation of a nucleophile and the nucleophile's ability to bind CO 2 . Herein, we seek to extend this analysis to quinones due to their high importance in the field of reactive carbon capture.…”

“…Once values for [CO 2 ] and DE 1 2 (or DE p ) were obtained for each data point, a plot of [CO 2 ] vs. DE 1 2 was constructed for each quinone. A user-defined fit function in Origin 2019b was used to determine a best-fit curve with free parameter K based upon eqn (10). The value of n in this equation was defined for each quinone on the basis of DFT results for the favorability of the first and second CO 2 binding events.…”

Electrochemical Carbon Dioxide Capture and Concentration

“…A significant observation in this work was that the CO 2 binding affinities of the quinone dianions ( K CO 2 (DA) ) were linearly correlated with the reduction potentials. This trend has since been observed among a wider selection of quinones, ,,,− bipyridines, and more recently with N-heterocyclic carbene (NHC) analogues (using DFT-derived binding constants) …”