Electrode catalysts play a crucial role as the key determinant of the performance of fuel cells, a technology recognized as being central to the wider adoption of hydrogen-based energy. Electrode catalysts are composed of platinum nanoparticles distributed on a carbon support, and this carbon is known to degrade at high voltage due to oxidation. This article describes a technique for assessing catalyst durability through in-situ observation under an SEM/STEM in a controlled atmosphere. The technique introduces air to create an oxidizing atmosphere and performs in-situ observation of the degradation process. Simultaneous SEM/STEM observation identified the sinking of platinum particles due to carbon oxidization as one of the degradation mechanisms. This direct observation of this degradation process will provide a valuable analytical technique for the future design of materials with high durability.
Professor, Ph.D. in Chemistry, International Research Center for Hydrogen Energy, Kyushu University.