Polyquinone Modification Promotes CO₂ Activation and Conversion to C₂₊ Products over Copper Electrode

Abstract

Electrocatalytic CO 2 reduction to value-added chemicals is a promising route to address the global warming problem. However, it still confronts low conversion efficiency and poor selectivity, due to difficulties in activating the inert CO 2 molecule and controlling the complex reaction pathways. Here, we put forward an unconventional approach to activating CO 2 by utilizing the quasi-reversible bonding between electrochemically reduced quinone groups and CO 2 . Through surface modification with polyquinone, the C 2+ production is effectively enhanced on a polycrystalline Cu foil model electrode. By further incorporating the polyquinone into a Cu gas diffusion electrode (GDE), a high C 2 H 4 partial current density of 325 mA/cm 2 is achieved at a low cell voltage of 3.5 V for CO 2 /pure water coelectrolysis. Combined with in situ ATR-SEIRAS study, the increased C 2+ product selectivity is attributed to the quinone-accelerated CO 2 -to-*CO conversion, which creates a high *CO coverage on Cu surface and thus facilitates C−C coupling for C 2+ production.

Recent Advances in Defect and Interface Engineering for Electroreduction of CO₂ and N₂

“…Stabilizing reaction intermediates is important to improve the conversion efficiency and yield of target products. It is an effective way to solve this problem to combine catalytic materials with polymers 76,[94][95][96][97][98] . It has been found that when polymers are combined with inorganic catalysts, the polymer-specific groups can regulate the electronic structure of the catalysts and the state of their surface microenvironment during the reaction.…”

“…Li et al activated CO2 by using the quasi-reversible bond between electrochemical reduction quinone group and CO2 96 . By further incorporating hydroquinone into the Cu GDEs, a high C2H4 partial current density of 325 mAꞏcm −2 is achieved at a low battery voltage of 3 V for CO2/pure water co-electrolysis.…”

Membrane Electrode Assembly for Electrocatalytic CO2 Reduction: Principle and Application

“…By impregnating QAPEEK ionomer into the porous Cu GDE to further increase the ESA (Figure 17e), the CO 2 /pure water co‐electrolyser reached a C 2 H 4 partial current density of 420 mA cm −2 at a cell voltage of 3.54 V (Figure 17f). Recently, the same group has found that polyquinone can accelerate CO 2 ‐to‐*CO conversion, creating a high *CO coverage on Cu surface and thus facilitating C−C coupling for C 2+ generation [121] …”

“…Recently, the same group Angewandte Chemie Aufsätze has found that polyquinone can accelerate CO 2 -to-*CO conversion, creating a high *CO coverage on Cu surface and thus facilitating CÀ C coupling for C 2 + generation. [121] Apart from the above methods based on catalyst design for C 2 + production towards CO 2 RR, cascade CO 2 electroreduction via a two-step process is another alternative for C 2 + generation. Here CO 2 will be first reduced to CO and then CÀ C coupling will be achieved in the second step of CO to C 2 + .…”

Organic-moiety-engineering on copper surface for carbon dioxide reduction

“…80 The organic polymers with tunable functional groups can effectively stabilize intermediates and are ideal for improving the catalytic activity of Cu catalysts. 81 Amino group is a kind of Lewis base which affinity for CO 2 and intermediates that has been demonstrated to be work in C-C coupling. Polyaniline (PANI) is a star conductive polymer that has been widely studied in energy storage and conversion, including CO 2 RR.…”