Tuning the selectivity of bimetallic Cu electrocatalysts for CO₂ reduction using atomic layer deposition

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical reduction of carbon dioxide (CO2) is a promising route for sustainable chemical production.
• Copper-based catalysts are widely studied for CO2 electroreduction but often suffer from poor selectivity.
• Atomic layer deposition (ALD) offers precise control over catalyst surface modification.

Purpose of the Study:

• To investigate the effect of atomically precise surface modification of copper catalysts using ALD with zinc oxide (ZnO) on CO2 electroreduction selectivity.
• To understand how surface chemical state changes influence product distribution.

Main Methods:

• Synthesis of Cu-Zn bimetallic catalysts on 3-D gas diffusion electrodes using ALD.
• Electrochemical evaluation of CO2 reduction performance.
• Analysis of product selectivity (e.g., C2H4, CO).

Main Results:

• ALD of ZnO on Cu catalysts significantly altered product selectivity compared to unmodified Cu.
• Even a single ALD cycle of ZnO reduced ethylene (C2H4) production.
• A notable shift towards carbon monoxide (CO) selectivity was observed.
• Changes in the surface chemical state were identified as the cause for selectivity variations.

Conclusions:

• Atomically precise surface modifications using ALD are effective in tuning electrocatalyst selectivity.
• ZnO ALD on Cu catalysts offers a strategy to enhance CO selectivity in CO2 electroreduction.
• Understanding surface chemistry is crucial for designing efficient CO2 reduction catalysts.