Electrochemical Behavior of Platinum in Fuel Cell Systems

Platinum remains the benchmark electrocatalyst for oxygen reduction and hydrogen oxidation reactions in fuel cell systems owing to its high activity and relative chemical stability. Under operational conditions, however, platinum surfaces undergo dynamic transformations that include the formation of surface oxides, transient dissolution and redeposition, and structural reorganisation at the nanoscale. These processes collectively govern long-term performance, durability and catalyst utilisation in proton exchange membrane fuel cells (PEMFCs) and related technologies. The interplay between applied potential, nanoparticle size and shape, support interactions and electrolyte composition dictates the onset of oxide formation, the kinetics of oxide reduction and the pathways for platinum dissolution. State-of-the-art studies employ in situ spectroscopies and scattering techniques alongside computational models and data-driven methods to resolve atomistic mechanisms of oxidation, to map stability windows via surface Pourbaix diagrams, and to predict dissolution rates under realistic cycling protocols. Advances in understanding these phenomena are crucial for minimising platinum loss, improving catalyst lifetime and realising economically viable fuel cell systems for transport and stationary power applications.

Research from Nature Portfolio

Machine learning-enhanced modelling has enabled the rapid construction of surface Pourbaix diagrams for real-scale platinum nanoparticles, capturing size- and shape-dependent trends in oxidation stability. By embedding bond-type information into graph neural networks, adsorption energies and oxide phase boundaries can now be predicted for particles up to several nanometres in diameter, facilitating accelerated screening of catalyst formulations under a range of pH and potential conditions.

In situ shell-isolated nanoparticle-enhanced Raman spectroscopy has revealed discrete intermediate oxide phases on single-crystalline platinum surfaces during anodic polarisation. Studies of Pt(111) and Pt(100) electrodes in acidic media have identified peroxo-like and superoxo-like two-dimensional surface oxides and the subsequent growth of amorphous three-dimensional PtO₂. This sequential oxidation pathway has provided a mechanistic basis for understanding potential-driven degradation and guided strategies to mitigate oxidative damage in fuel cell electrodes.

Electrochemical Behavior of Platinum in Fuel Cell Systems publication trend

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

Technical terms

Electrocatalyst: A material that accelerates an electrochemical reaction at an electrode surface.

Pourbaix diagram: A potential–pH map indicating thermodynamically stable phases of a material in aqueous environments.

Transient dissolution: The rapid, potential-driven release of metal atoms from the surface during sudden changes in electrode potential.

Surface oxide: A thin layer of oxidised species formed on a metal electrode under anodic polarisation.

Proton exchange membrane fuel cell (PEMFC): A type of fuel cell that uses a polymer membrane to conduct protons from the anode to the cathode.

References

1. Machine learning-enabled exploration of the electrochemical stability of real-scale metallic nanoparticles. Nature Communications (2023).
2. Intermediate stages of electrochemical oxidation of single-crystalline platinum revealed by in situ Raman spectroscopy. Nature Communications (2016).
3. Electrochemical oxidation of Pt(111) beyond the place-exchange model. Electrochimica Acta (2022).
4. The Oxidation of Platinum under Wet Conditions Observed by Electrochemical X‑ray Photoelectron Spectroscopy. Journal of the American Chemical Society (2019).
5. Platinum Dissolution and Redeposition from Pt/C Fuel Cell Electrocatalyst at Potential Cycling. Journal of The Electrochemical Society (2018).