Polymer-Covered Copper Catalysts Alter the Reaction Pathway of the Electrochemical CO₂ Reduction Reaction

Abstract

The electrochemical CO 2 reduction reaction (CO 2 RR) has attracted considerable attention recently due to the potential conversion of atmospheric CO 2 into useful organic products by utilizing electricity from renewable energy sources. However, the selective formation of desired products only via CO 2 RR has been elusive due to the presence of a myriad of competing reaction pathways, thus calling for effective strategies controlling the reaction coordinates. The control of binding energies of the reaction intermediate, such as *CO, is pivotal to manipulating reaction pathways, and various attempts have been made to accomplish this goal. Herein, we introduce recent endeavors to increase the catalytic selectivity of Cu-based catalysts by surface modification with polymer coating, which can change the local pH, hydrophilicity/hydrophobicity, reaction concentration, etc. The polymer conjugation also contributed to the enhanced electrocatalytic stability of Cu-based catalysts during the CO 2 RR. We also point to the remaining challenges and provide perspectives on the further development of Cu–polymer hybrid catalysts for the practical CO 2 RR.

Strategies to Modulate the Copper Oxidation State Toward Selective C2+ Production in the Electrochemical CO2 Reduction Reaction

“…FEs of C 1 and C 2 products were acquired for the various oxidation states of Cu (Figure 8e); the FE C2 reached as high as 79% ± 2% (52% ± 2% ethylene and 27% ± 1% ethanol) when the average valence of Cu was +0. 35. At the same time, the reduction of CO 2 to methane was suppressed to 0.08%, which enhanced the C 2 selectivity.…”

Reaction microenvironment control in membrane electrode assemblies for CO2 electrolysis

“…25 While ligands blocking surface sites are usually considered to be detrimental to catalysis, an increasing number of reports have indicated that some ligands with appropriate design can also play a positive catalytic role in CO 2 electrolysis. [26][27][28][29][30] The incorporation of such ligands onto catalyst surfaces does not directly introduce alternative active sites, but would create specific reaction microenvironments that can influence the activity and selectivity of CO 2 electrolysis via steric and electronic effects. [26][27][28][29][30] These molecular modifications are expected to control reaction pathways via manipulating electrode hydrophilicity/hydrophobicity, modulating interfacial cation solvation, tuning the adsorption of reaction intermediates, inducing additional chemical activation of CO 2 as well as increasing ion conductivity in MEA electrolyzers.…”

Co-sensitization of Copper Indium Gallium Disulfide and Indium Sulfide on Zinc Oxide Nanostructures: Effect of Morphology in Electrochemical Carbon Dioxide Reduction

“…Converting carbon dioxide (CO 2 ) into valuable chemicals and fuels has made an impact on reducing our carbon footprint. − However, the high stability of CO 2 for conversion into different chemicals restricts the application. Therefore, the research community has focused on developing materials and systems for efficient CO 2 conversion by reducing the high activation energy of CO 2 . − It is possible to achieve CO 2 reduction via various routes, including photocatalytic and electrochemical conversion. − In this way, besides decreasing carbon emissions, value-added chemicals, such as methanol, hydrogen, formic acid, and syngas, can be produced. − Among these chemicals, formic acid stands out as an alternative to fossil fuels due to its advantages, such as being an energy-intensive material, having a high volumetric hydrogen density, and having enormous potential as an effective hydrogen storage vector .…”