Enhancing CO₂ Electroreduction to Ethylene in Acidic Solution by Optimizing Cation Configuration on the Cu Surface

Area of Science:

• Electrochemistry
• Catalysis
• Sustainable Chemistry

Background:

• CO2 electroreduction to C2H4 is key for carbon neutrality but faces challenges in acidic media, including weak CO intermediate adsorption and competing hydrogen evolution reaction (HER).
• Theoretical insights suggest K+ cations, with minimized bound water, can enhance CO adsorption and promote C2H4 formation.

Purpose of the Study:

• To develop a catalyst that enhances C-C coupling for CO2 electroreduction to C2H4 in acidic environments.
• To overcome limitations of weak *CO intermediate adsorption and suppress the hydrogen evolution reaction (HER).

Main Methods:

• Development of a modified copper catalyst (CuTEA) by adjusting Nafion ionomer distribution in the catalyst layer.
• Strategic modification to lower K+ bound water content and increase surface K+ concentration on the Cu electrode.
• Electrochemical testing in an acidic electrolyte (pH = 1).

Main Results:

• The CuTEA catalyst achieved a 70.2% Faradaic efficiency for C2H4 production.
• A high partial current density of 561.6 mA cm-2 for C2H4 was recorded.
• The catalyst design successfully promoted C-C coupling and suppressed HER.

Conclusions:

• The CuTEA catalyst effectively promotes CO2 electroreduction to C2H4 in acidic media by optimizing K+ cation interaction and water management.
• This work offers a promising strategy for efficient and selective C2H4 synthesis, contributing to sustainable chemical manufacturing and carbon neutrality goals.