Enhanced Electrocatalytic CO2 Reduction to C2+ Products by Adjusting the Local Reaction Environment with Polymer Binders. Issue 9 (5th January 2022)

• Record Type: Journal Article
• Authors: Pham, Thi Ha My; Zhang, Jie; Li, Mo; Shen, Tzu‐Hsien; Ko, Youngdon; Tileli, Vasiliki; Luo, Wen; Züttel, Andreas
• Is Part Of: Advanced energy materials. Volume 12:Issue 9(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-05
• Subjects: CO 2 reduction -- copper catalysts -- electrocatalysis -- hydrophobicity -- polymer binders; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202103663
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: The activity and selectivity of the electrochemical CO2 reduction reaction (CO2 RR) are often hindered by the limited access of CO2 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 CO2 relative to H2 O at the vicinity of the catalyst and thus the performance of CO2 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 (C2+ ) products. The FEP coated catalyst exhibits a C2+ 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 H2 O and enhances that of the reactant (i.e., CO2 ) 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. Abstract : Polymer binders can effectively modulate the accessibility of CO2 relative to H2 O in the vicinity of catalysts in the electrochemical CO2 reduction reaction. Hydrophobic binders can greatly improve the selectivity for multi‐carbon products (C2+ ), suggesting that tuning the hydrophobicity of electrocatalysts with polymer binders is a promising way to optimize the performance of electrochemical reactions involving gas–solid–liquid interfaces.