Catalyst Functionalization for Elevating Performance in Ammonia Protonic Ceramic Fuel Cells via Relay...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Direct ammonia proton ceramic fuel cells (NH3-PCFCs) offer a promising route for ammonia-to-power conversion at intermediate temperatures (400°C-600°C).
• However, NH3-PCFCs face challenges due to sluggish reaction kinetics, including ammonia oxidation, decomposition (ADR), and hydrogen oxidation (HOR), resulting in high overpotentials and low current densities.

Purpose of the Study:

• To enhance the performance of NH3-PCFCs by employing a relay thermo-electrocatalysis strategy.
• To investigate the effectiveness of catalyst functionalization in improving NH3-PCFC efficiency and power output.

Main Methods:

• Synthesized a functionalized catalyst, Ru/CZ4, to implement the relay thermo-electrocatalysis strategy.
• Implemented a system where ammonia first undergoes ADR at a catalytic layer and then proceeds to the anode for HOR.
• Conducted comparative performance tests using bare cells and functionalized cells with both H2 and NH3 fuels.

Main Results:

• The Ru/CZ4 functionalized cell achieved a peak power density (PPD) of 615 mW cm⁻² with H2 and 576 mW cm⁻² with NH3.
• These results represent a 1.8-fold and 2.0-fold increase compared to bare cells (327 mW cm⁻² for H2, 283 mW cm⁻² for NH3).
• The ammonia-to-hydrogen PPD ratio reached 93.7%, demonstrating excellent performance across both fuel types.

Conclusions:

• The relay thermo-electrocatalysis strategy significantly enhances NH3-PCFC performance.
• Catalyst functionalization, as demonstrated by Ru/CZ4, is a viable approach for optimizing NH3-PCFCs.
• This research provides valuable insights for designing and improving solid oxide fuel cells utilizing hydrogen-rich fuels like ammonia.