Tailoring Interlayer Microenvironment of 2D Layered Double Hydroxides for CO₂ Reduction with Enhanced C₂₊ Production

Area of Science:

• Electrocatalysis
• Materials Science
• Chemical Engineering

Background:

• Catalyst properties and catalyst layer (CL) structure on gas diffusion electrodes (GDEs) are vital for carbon dioxide reduction reaction (CO2RR) efficiency and selectivity.
• Harsh CO2RR conditions cause uncontrollable catalyst changes, hindering tailored surface properties and microstructures for desired products.

Purpose of the Study:

• To rationally tune the interlayer microenvironment of copper-based layered double hydroxides (LDHs) via ink solvent engineering.
• To investigate the impact of tuned microenvironment on CL surface characteristics and microstructure for CO2RR.
• To enhance catalytic activity and product selectivity for multi-carbon products.

Main Methods:

• Ink solvent engineering to tune the interlayer microenvironment of copper-based LDHs.
• Fabrication of catalyst layers (CLs) on gas diffusion electrodes (GDEs).
• Utilized in situ and ex situ techniques to analyze CL properties and catalytic performance.

Main Results:

• Optimized surface wettability and thickness of porous CLs were achieved.
• These optimized CLs controlled local CO2 concentration and water dissociation, crucial for hydrogenation.
• Achieved a high Faradaic efficiency of 75.3% for C2+ products and a partial current density of 275 mA cm-2 at -0.8 V vs RHE.

Conclusions:

• Ink solvent engineering of copper-based LDHs provides a facile method to tune CL microenvironment.
• Surface wettability and thickness of CLs are critical for efficient CO2RR and multi-carbon product generation.
• This work offers insights for designing efficient electrocatalysts for CO2RR, focusing on multi-carbon products.