Scientists at ICGM Montpellier just published their work entitled “Metal-oxide phase transition of platinum nanocatalyst below fuel cell open-circuit voltage” in the prestigious journal Nature Communications.
Fuel cells, a key technology for the energy transition, rely on electrochemical reactions to convert hydrogen into electricity. Platinum, the essential catalyst for oxygen reduction at the cathode, has limited durability in real-life systems, however, hampering the large-scale deployment of this promising solution.
In this fruitful study, researchers from CNRS – ICGM Montpellier, in collaboration with the ID31 light line at The European Synchrotron (ESRF) and CIRIMAT Toulouse, observed the behavior of platinum in real operation (operando) in a fuel cell.
Using high-energy X-ray diffraction generated by ESRF-EBS, they discovered that platinum undergoes multiple transitions between its metallic phase and an unstable amorphous oxide phase, at precise critical voltages. This phenomenon, not observed under model conditions, explains the accelerated dissolution of platinum, limiting its durability.
These results pave the way for exploring new strategies for stabilizing platinum, whether by rethinking the design of the material itself or optimizing the control of the fuel cell system.