Steering Hydrocarbon Selectivity in CO₂ Electroreduction over Soft-Landed CuO Nanoparticle-Functionalized Gas...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Physical vapor deposition methods are crucial for fabricating efficient catalyst layers for carbon capture and utilization (CCU).
• The CO2 reduction reaction (CO2RR) is a key process for CCU, but catalyst selectivity and efficiency need improvement.

Purpose of the Study:

• To synthesize CuO nanoparticles (NPs) using a sputter gas aggregation source (SGAS) for CO2RR.
• To investigate the effect of NP morphology on CO2RR selectivity and performance.
• To optimize catalyst layers for enhanced CCU processes.

Main Methods:

• Controlled synthesis of CuO NPs using SGAS and a multiple ion cluster source.
• Fabrication of catalyst layers on gas diffusion electrodes.
• Characterization using atomic force microscopy, electron microscopy, and quasi in situ X-ray photoelectron spectroscopy.
• Electrochemical testing of CO2RR performance in a gas-fed electrolyzer.

Main Results:

• Achieved peak CH4 partial current density of -143 mA cm-2 (48% Faradaic efficiency) and multicarbon partial current density of -231 mA cm-2 (76% Faradaic efficiency).
• Demonstrated control over hydrocarbon selectivity by varying mass loading, influencing NP film morphology.
• Ruled out NP size and in situ oxidation state as primary factors for selectivity divergence.

Conclusions:

• SGAS-generated NP films offer tunable properties and homogeneity for CO2RR catalyst optimization.
• Controlling NP film morphology via SGAS parameters is key to directing CO2RR selectivity.
• This approach shows potential for upscaling advanced CCU technologies.