Promoting Water Activation via Molecular Engineering Enables Efficient Asymmetric C-C Coupling during CO₂...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Water activation is critical for efficient carbon dioxide (CO2) reduction.
• Controlling water activation electrochemically remains a significant challenge for improving CO2 reduction performance.
• Engineering catalyst surfaces is key to enhancing selectivity and efficiency.

Purpose of the Study:

• To improve electrochemical CO2 reduction to ethene and ethanol with high selectivity.
• To promote water dissociation and asymmetric C-C coupling using engineered copper (Cu) surfaces.
• To understand the role of N-H-rich molecules in accelerating interfacial water dissociation and CO2 conversion.

Main Methods:

• Electrochemical CO2 reduction experiments.
• Surface engineering of Cu catalysts with N-H-rich molecules.
• Spectroscopic analysis and density functional theory (DFT) calculations.
• Cu surface facet regulation to control intermediate coverage.

Main Results:

• N-H-rich molecules accelerate water dissociation via hydrogen-bond interactions.
• Generated hydrogen species facilitate the conversion of *CO to *CHO, enabling efficient asymmetric *CHO-*CO coupling.
• Faradaic efficiency for C2 products increased by ~30% compared to unmodified catalysts.
• Selectivity between C2 products and methane (CH4) was tunable via Cu surface facet engineering.
• Modified Cu2O nanocubes achieved 85.7% FE for C2 products at 800 mA cm-2 with excellent stability.

Conclusions:

• Engineered Cu surfaces with N-H-rich molecules provide an effective strategy for enhancing electrocatalytic CO2 reduction.
• Accelerated water dissociation is crucial for improving the efficiency and selectivity of C2 product formation.
• This study offers mechanistic insights and a general approach for designing advanced electrocatalysts for CO2 conversion.