Oxygen Reduction Electrocatalysis in Fuel Cell Applications

The oxygen reduction reaction (ORR) is the cathodic process that governs the efficiency and power output of fuel cells by electrochemically converting molecular oxygen into water or hydroxide ions. Its inherently sluggish kinetics impose significant overpotentials, rendering it the primary performance bottleneck. Traditional platinum-based catalysts, while highly active, suffer from high cost, limited supply and susceptibility to poisoning. As a result, current research has focused on alternative approaches such as alloying with non-precious metals to tune the d-band centre, engineering nanoscale morphology to enhance surface strain and defect density, and deploying single-atom sites on conductive supports to maximise atom utilisation. Coupled experimental and theoretical studies are advancing the rational design of catalysts that offer reduced precious-metal content, improved mass activity and extended durability under realistic fuel cell conditions. These developments are pivotal for scaling fuel cell technologies in applications from transport to stationary power systems.

Research from Nature Portfolio

Recent studies have developed dendritic palladium–copper–cobalt trimetallic nanoalloys featuring defect-rich architectures that deliver superior ORR mass activities and long-term stability. Synergistic effects arising from surface strain, defect sites and d-band modulation underpin their high performance compared to commercial references. In parallel, controlled alloying of palladium with silver has been shown to optimise adsorbate binding energies through ligand effects, achieving up to fivefold intrinsic activity enhancements at 0.9 V in alkaline media while substantially reducing precious-metal content. These foundational advances offer blueprints for designing cost-effective, highly active ORR electrocatalysts.

Oxygen Reduction Electrocatalysis in Fuel Cell Applications publication trend

The graph below shows the total number of articles in oxygen reduction electrocatalysis in fuel cell applications across all publications each year (not limited to Nature Index journals).

Technical terms

Oxygen reduction reaction (ORR): The multi-step electrochemical conversion of molecular oxygen into water or hydroxide ions, representing the cathodic process in fuel cells.

Electrocatalyst: A material that accelerates an electrochemical reaction by providing active sites for reactant adsorption and electron transfer.

d-band centre: A descriptor of the electronic structure of transition metal catalysts, indicating the energy level of d-electron bands that governs adsorbate binding strength.

Single-atom catalyst (SAC): A catalyst system in which individual metal atoms are dispersed on a support, maximising atom utilisation and creating uniform active sites.

Mass activity: The catalytic current per unit mass of precious metal at a defined potential, used to assess catalyst efficiency.

Half-wave potential: The electrode potential at which half of the limiting current density is achieved in a voltammetric measurement, indicating catalytic activity.

References

1. Acetic acid‐assisted mild dealloying of fine CuPd nanoalloys achieving compressive strain toward high‐efficiency oxygen reduction and ethanol oxidation electrocatalysis. Carbon Energy (2023).
2. Dendritic defect-rich palladium–copper–cobalt nanoalloys as robust multifunctional non-platinum electrocatalysts for fuel cells. Nature Communications (2018).
3. Tuning the electronic structure of Ag-Pd alloys to enhance performance for alkaline oxygen reduction. Nature Communications (2021).
4. Recent advances in Fe‐N‐C single‐atom site coupled synergistic catalysts for boosting oxygen reduction reaction. Electron (2024).
5. Atomically Engineered Defect‐Rich Palladium Metallene for High‐Performance Alkaline Oxygen Reduction Electrocatalysis. Advanced Science (2024).