Spatial Regulated Noncontact Ru Heterostructure for Cost-Effective Platinum-Free Fuel Cells

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The hydrogen oxidation reaction (HOR) is critical for fuel cells but suffers from sluggish kinetics.
• Rational design of heterostructure catalysts is key for optimizing multi-intermediate electrochemical reactions.
• Ruthenium (Ru) is a cost-effective alternative for HOR catalysis, but its efficiency needs enhancement.

Purpose of the Study:

• To develop a noncontact heterostructure catalyst with spatially separated but synergistic components for efficient alkaline HOR.
• To investigate the performance of Ru-MoC/C catalysts in anion exchange membrane fuel cells (AEMFCs).
• To assess the catalyst's potential to meet or exceed U.S. Department of Energy (DOE) targets.

Main Methods:

• Synthesis of a noncontact heterostructure catalyst (Ru-MoC/C) with Ru nanoparticles and MoC clusters on a carbon support.
• Electrochemical characterization of the catalyst's HOR activity and performance in H2-air AEMFCs.
• Density functional theory (DFT) calculations to understand the catalyst's mechanism and synergistic effects.

Main Results:

• The Ru-MoC/C catalyst demonstrated a refined division of labor and seamless functional collaboration.
• The AEMFC achieved a peak power of 17.4 W mgPGM−1 with ultralow Ru loading (0.05 mgRu cm−2).
• The Pt-free AEMFC surpassed the DOE 2025 target for PGM utilization (13.4 W mg−1 at 0.65 V) and showed stable operation (>110 h at 0.5 A cm−2).

Conclusions:

• Noncontact heterostructure design is a promising strategy for developing efficient and durable electrocatalysts.
• The Ru-MoC/C catalyst offers a cost-effective and high-performance solution for alkaline HOR.
• This work advances the development of platinum-group-metal-free fuel cell technologies.