Importance of Particle Size and Distribution in Achieving High-Activity, High-Stability Oxygen Reduction Catalysts

Strongly interacting catalyst supports can influence the nucleation, growth, dispersion, and shape of supported nanoparticles that impact catalytic activity and stability. However, there is little understanding of the limitations of support interactions, and the ability to quantitatively relate particle growth and loading to activity and stability is lacking. Here, we report a statistical framework to quantify the growth of a binary distribution of Pt nanoparticles on tin-doped indium oxide and predict mass and specific activity for the oxygen reduction reaction in acid media with increased Pt loading. Our results reveal that the growth mechanism for Pt on the oxide is directly related to its exceptional electrochemical activity and provide new insight into the relationship between nanoparticle size distribution and activity trends. We also show that catalyst degradation mechanisms can be controlled or altogether eliminated through strong metal-support interactions. The results of this work provide insights into how catalyst preparation influences material and chemical properties and how to develop design goals for next generation catalysts.