Highly Efficient Electrocatalytic CO₂ Reduction to C₂₊ Products on a Poly(ionic liquid)‐Based Cu⁰–Cu^I Tandem Catalyst

Abstract

Electroreduction of CO 2 on a polymer-modified Cu-based catalyst has shown high multi-electron reduction (> 2 e À ) selectivity, however, most of the corresponding current densities are still too small to support industrial applications. In this work, we designed a poly(ionic liquid) (PIL)-based Cu 0 -Cu I tandem catalyst for the production of C 2 + products with both high reaction rate and high selectivity. Remarkably, a high C 2 + faradaic efficiency (FE C 2þ ) of 76.1 % with a high partial current density of 304.2 mA cm À 2 is obtained. Mechanistic studies reveal the numbers and highly dispersed Cu 0 -PIL-Cu I interfaces are vital for such reactivity. Specifically, Cu nanoparticles derived Cu 0 -PIL interfaces account for high current density and a moderate C 2 + selectivity, whereas Cu I species derived PIL-Cu I interfaces exhibit high activity for CÀ C coupling with the local enriched *CO intermediate. Furthermore, the presence of the PIL layer promotes the C 2 + selectivity by lowering the barrier of CÀ C coupling.

Hydrophobic, Ultrastable Cuδ+ for Robust CO2 Electroreduction to C2 Products at Ampere-Current Levels

“…Compared to the Cu Ref catalyst, blue shifts in the Cu–CO stretching band are observed at the same potentials, indicating a stronger Cu–CO bond on the Cu CF catalyst to favor the C–C coupling step for subsequent generation of C 2+ products, as reported previously . Besides, the Cu CF catalyst exhibited three peaks associated with the Cu δ+ at around 415, 520, and 620 cm –1 in the lower-energy region (Figure c). ,, As the applied cathode overpotential increases, these characteristic peaks of Cu δ+ are still retained, indicating a stabilization of the Cu valence state in the Cu CF catalyst. In the higher-energy region, signals at around 1015 and 1066 cm –1 are ascribed to the adsorbed HCO 3 – and CO 3 2– , respectively (Figure S41).…”

“…30 Besides, the Cu CF catalyst exhibited three peaks associated with the Cu δ+ at around 415, 520, and 620 cm −1 in the lower-energy region (Figure 3c). 13,33,34 As the applied cathode overpotential increases, these characteristic peaks of Cu δ+ are still retained, indicating a stabilization of the Cu valence state in the Cu CF catalyst. In the higher-energy region, signals at around 1015 and 1066 cm −1 are ascribed to the adsorbed HCO 3 − and CO 3 2− , respectively (Figure S41).…”

Steering carbon dioxide reduction toward C–C coupling using copper electrodes modified with porous molecular films

“…In previous work on CO 2 RR, the porosity of the polymer was demonstrated to be important for mass transport of the species concerned 31 , 45 . In fact, the specific morphology of the polymer could even facilitate the supply of CO 2 to the Cu-polymer interface by speeding up the diffusion of CO 2 46 . To examine the deposited films from this perspective, we selected a well-known redox probe, 1,1′-dimethyl-4,4′-bipyridinium dichloride (methyl viologen), for a cyclic voltammetric study.…”

Rational Design of Metal–Organic Frameworks for Electroreduction of CO2 to Hydrocarbons and Carbon Oxygenates

“…Generally, the pathways of C–C coupling are largely dependent on the types of catalytic systems. For instance, as for Cu(100) 51 and Cu(111) 52 facets, there is an array arrangement of closely adjacent copper atoms (<2.6 Å) on their surface. Such a short Cu–Cu distance is beneficial to the direct C–C coupling between two *CO intermediates ( i .…”