Persistent CO₂ Reduction Performance of an Ag Nanoparticle Gas Diffusion Electrode in Realistic Dynamic PV-Driven...

Area of Science:

• Electrochemistry
• Catalysis
• Renewable Energy

Background:

• CO2 reduction catalysts are crucial for solar fuel production but often tested under steady-state conditions.
• Reliable renewable energy storage requires CO2 electroreduction to tolerate power intermittency from sources like photovoltaics (PV).

Purpose of the Study:

• To develop and test CO2 electroreduction catalysts that maintain consistent performance under dynamic power input from PV systems.
• To demonstrate the feasibility of directly coupling CO2 electrolyzers to PV devices for efficient energy storage and carbon utilization.

Main Methods:

• Selected a silver (Ag) nanoparticle gas diffusion cathode for stable CO production across a wide current density range.
• Directly coupled the Ag cathode system to a hardware-emulated silicon (Si)-PV module operating under a realistic sunny day profile.

Main Results:

• Achieved 96% energy coupling efficiency between the PV module and the CO2 electrolyzer.
• Reached a cumulative solar-to-chemical (CO) efficiency of 8.8% within one day.
• Demonstrated stable CO production from the Ag cathode under variable current densities.

Conclusions:

• Ag-based cathodes show significant potential for robust performance in variable PV-powered CO2 reduction systems.
• Introduced a novel testing methodology that better simulates real-world PV-electrolyzer integration.
• Advanced the practical implementation of solar-driven CO2 reduction for energy storage and carbon utilization.