Stability and dissolution of electrocatalysts: Building the bridge between model and "real world" systems

This review gives a snapshot of the current state of the electrocatalyst stability research. The accent is put on the dissolution of the state-of-the-art oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) Pt- and Ir-or Ru-based catalysts, respectively. Two important aspects at the cutting edge of the ORR and OER catalyst stability research, viz. stability of the catalyst layers containing very small loadings of Pt and Ir/Ru and the question of the conformity of the model dissolution studies with degradation of the "real world" catalyst layers are highlighted. It is shown that in both systems catalyst degradation accelerates with decrease in catalyst loading. Situation is more complex though, when model and real systems are contrasted. Thus, while dissolution of Pt is comparable, no convincing comparison for Ir/Ru can be provided yet. The potential near future research directions are emphasized throughout the text.