Electrocatalysis in Fuel Cell Technologies

Electrocatalysis lies at the heart of fuel cell operation, mediating the hydrogen oxidation reaction at the anode and the oxygen reduction reaction at the cathode to convert chemical energy into electrical power. Platinum and its alloys have long served as the benchmark catalysts, yet their scarcity, high cost and susceptibility to deactivation by carbon monoxide poisoning or particle degradation pose significant challenges. Advances in nanostructuring, single‐atom dispersion and core–shell architectures seek to enhance activity, selectivity and durability while reducing noble‐metal loading. Innovations in support materials—from graphitised carbons to conductive metal oxides—improve catalyst stability and mass transport. In parallel, in situ and operando characterisation techniques have unveiled dynamic surface transformations and reaction intermediates, guiding the rational design of robust electrocatalysts. Such progress is vital to the global deployment of proton‐exchange membrane fuel cells in transport, stationary power and portable devices, and to emerging alkaline and anion‐exchange systems that promise lower precious‐metal requirements. By bridging fundamental insights with applied engineering, the field continues to drive the transition towards clean and efficient energy conversion.

Research from Nature Portfolio

In situ high‐energy‐resolution fluorescence‐detection X-ray absorption spectroscopy was employed to probe water and oxygen adsorption on platinum and platinum–cobalt nanoparticles under realistic fuel cell conditions. The study revealed that co‐adsorption of O₂ and H₂O amplifies surface oxidation and contributes to overpotential losses. Alloy composition and particle size were shown to modulate both individual and cooperative adsorption strengths, providing actionable guidelines for tailoring nanoparticle surface chemistry to optimise oxygen reduction kinetics in hydrated environments.

Research from all publishers

1. A mechanistic study using rhodium‐based single‐atom catalysts demonstrated that the reactivity of adsorbed hydroxyl intermediates, rather than carbon monoxide binding strength, governs CO electro-oxidation rates. RhN₄ centres exhibited markedly superior activity to platinum‐on‐carbon benchmarks, signalling a paradigm shift towards engineering water‐related reaction intermediates in anode electrocatalysts.
2. Identical‐location scanning transmission electron microscopy tracked the evolution of rhodium–platinum core–shell nanoparticles during extended potential cycling. The nanoparticles displayed high intrinsic stability, with main degradation attributed to particle detachment from the carbon support. These findings underline the importance of metal–support interactions in sustaining anode catalyst durability.
3. A comprehensive review of in situ characterisation techniques for cathode oxygen reduction outlined the use of X-ray absorption spectroscopy, X-ray diffraction and spectroelectrochemical methods to elucidate ORR mechanisms, nanoparticle degradation pathways and contaminant poisoning. Insights from these studies inform the design of catalysts with enhanced activity, oxidation resistance and tolerance to air‐borne impurities.

Electrocatalysis in Fuel Cell Technologies publication trend

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

Technical terms

Overpotential: The extra potential required beyond the thermodynamic voltage to drive an electrochemical reaction at a specified rate.
Single-atom catalyst: A catalyst in which individual metal atoms are dispersed on a support, maximising atom efficiency and modifying electronic interactions.
Core–shell nanoparticle: A nanostructure comprising a central core material encased by a distinct shell layer, used to tune surface composition and enhance stability.
Hydrogen oxidation reaction (HOR): The anodic process in which molecular hydrogen is oxidised to protons and electrons in a fuel cell.
Oxygen reduction reaction (ORR): The cathodic process in which molecular oxygen is reduced to water or hydroxide ions, a key determinant of fuel cell performance.
Identical-location STEM: A transmission electron microscopy technique that examines the same region of individual nanoparticles before and after electrochemical testing to monitor structural changes.

References

1. Wetting Induced Oxidation of Pt-based Nano Catalysts Revealed by In Situ High Energy Resolution X-ray Absorption Spectroscopy. Scientific Reports (2017).
2. The decisive role of adsorbed OH* in low‐potential CO electro‐oxidation on single‐atom catalytic sites. Carbon Energy (2023).
3. Electrochemical Stability of Rhodium–Platinum Core–Shell Nanoparticles: An Identical Location Scanning Transmission Electron Microscopy Study. ACS Nano (2023).
4. Progress and Perspective for In Situ Studies of Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells. Advanced Science (2023).