Selectivity

Electrode

Organic chemistry

Nafion

Electrocatalyst

Engineering

Faraday efficiency

Catalysis

Physical chemistry

Composite material

Inorganic chemistry

Chemistry

Materials science

Polyacrylic acid

Chemical engineering

Polymer

Electrochemistry

Advanced Energy Materials

The activity and selectivity of the electrochemical CO 2 reduction reaction (CO 2 RR) are often hindered by the limited access of CO 2 to the catalyst surface and overtaken by the competing hydrogen evolution reaction. Herein, it is revealed that polymers used as catalyst binders can effectively modulate the accessibility of CO 2 relative to H 2 O at the vicinity of the catalyst and thus the performance of CO 2 RR. Three polymers with different hydrophilicities (i.e., polyacrylic acid (PAA), Nafion, and fluorinated ethylene propylene (FEP)) are selected as binders for Cu catalysts. At a thickness of only ≈1.2 nm, these binders strongly affect the activity and selectivity toward multi‐carbon (C 2+ ) products. The FEP coated catalyst exhibits a C 2+ partial current density of over 600 mA cm −2 with ≈77% faradaic efficiency at −0.76 V versus RHE. This high performance is attributed to the hydrophobic (aerophilic) properties of FEP, which reduces the local concentration of H 2 O and enhances that of the reactant (i.e., CO 2 ) and the reaction intermediates (i.e., CO). These findings suggest that tuning the hydrophobicity of electrocatalysts with polymer binders can be a promising way to regulate the performance of electrochemical reactions involving gas–solid–liquid interfaces.

Enhanced Electrocatalytic CO<sub>2</sub> Reduction to C<sub>2+</sub> Products by Adjusting the Local Reaction Environment with Polymer Binders

Enhanced Electrocatalytic CO2 Reduction to C2+ Products by Adjusting the Local Reaction Environment with Polymer Binders

Enhanced Electrocatalytic CO₂ Reduction to C₂₊ Products by Adjusting the Local Reaction Environment with Polymer Binders