Electrochemical Reduction of Carbon Dioxide to Methanol in the Presence of Benzannulated Dihydropyridine Additives

Abstract

Dihydropyridines (DHPs) have been postulated as active intermediates in the pyridine-mediated electrochemical conversion of CO2 to methanol, however the ability of isolated DHPs to facilitate methanol production in a similar fashion to their parent aromatic N-heterocycles (ANHs) has not been tested. Here, we use bulk electrolysis to show that 1,2-and 1,4-DHPs (1,2-dihydrophenanthridine and 9,10dihydroacridine) can mediate the sub-stoichiometric electrochemical reduction of CO2 to methanol and formate with similar Faradaic efficiencies as the corresponding ANHs at Pt electrodes. 1,2-dihydrophenanthridine furthermore exhibits improved CO2 reduction activity compared to its parent ANH (phenanthridine) at glassy carbon electrodes. These results provide the first experimental evidence for the participation of DHPs as additives in electrochemical CO2 reduction. TOC GRAPHIC Pt or Glassy CarbonCO 2 HCOO -CH 3 OH (DHP) pH ~ 5 E app

Hydride Shuttle Formation and Reaction with CO2on GaP(110)

“…Several adsorptionf ree energy studies found that Py and DHP favorably bind to the GaP surface, whereas CO 2 does not. [21] These studies suggest that hydrogenated N-heterocycles (HNHs)c an form on electrode surfaces under electrochemical conditions, and that such HNHsm ight be responsible for the heterogeneousr eduction of CO 2 . SCE computed for the solvated GaP(110) surface and À1.68 Vv s. SCE computed for the solvated reconstructed GaP(111)s urface).…”

Highly Efficient Electroreduction of CO2 to Methanol on Palladium–Copper Bimetallic Aerogels

“…[25][26][27][28] Thev arying composition in Pd x Cu y aerogels resulted in different Pd 0 /Pd II and Cu I + Cu 0 /Cu II radios,w hich was found to be correlated with the CO 2 electrocatalytic activity and CH 3 OH selectivity.M oreover, the special nanochain structure of aerogels also contributed to the enhancement of Pd/Cu grain boundaries and CH 3 OH production. We prepared as erious of Pd x Cu y bimetallic aerogels with controlled composition via at emplate-free self-assembly process.B y using Pd 83 Cu 17 bimetallic aerogels on carbon paper (CP) as electrode and 1-butyl-3-methylimidazoliumtetrafluoroborate ([Bmim]BF 4 )a queous solution as electrolyte,t he Faradaic efficiency for CH 3 OH production could reach 80.0 %w ith acurrent density of 31.8 mA cm À2 ,which is higher than those reported previously.…”

Highly Efficient Electroreduction of CO2 to Methanol on Palladium–Copper Bimetallic Aerogels

“…We prepared as erious of Pd x Cu y bimetallic aerogels with controlled composition via at emplate-free self-assembly process.B y using Pd 83 Cu 17 bimetallic aerogels on carbon paper (CP) as electrode and 1-butyl-3-methylimidazoliumtetrafluoroborate ([Bmim]BF 4 )a queous solution as electrolyte,t he Faradaic efficiency for CH 3 OH production could reach 80.0 %w ith acurrent density of 31.8 mA cm À2 ,which is higher than those reported previously. [25][26][27][28] Thev arying composition in Pd x Cu y aerogels resulted in different Pd 0 /Pd II and Cu I + Cu 0 /Cu II radios,w hich was found to be correlated with the CO 2 electrocatalytic activity and CH 3 OH selectivity.M oreover, the special nanochain structure of aerogels also contributed to the enhancement of Pd/Cu grain boundaries and CH 3 OH production.…”