It is established that activity and stability of electrocatalysts are related, but the intimate relationships are still not well understood. It is known that materials dissolution may be linked to the electrocatalytic activity of nanoparticles determining the steady-state concentrations of active defect sites formed during dissolution. On the other hand, it was demonstrated on the example of RuO2 and IrO2 that the potential onsets of oxygen evolution reaction (OER) and metal dissolution coincide well providing considerable evidence that dissolution is triggered by OER. Here, we will present some of our recent results based on ab initio molecular dynamics (AIMD) and thermodynamics approaches to analyze activity-stability relationships. On the example of goethite (α-FeOOH) we will show how the kinetics of iron dissolution varies between the (021) and (110) surfaces and depends on the dissolution mechanism (nonreductive, reductive and acidic). For noble-based metal electrocatalysts (Ir, Ru), receiving great interest as water splitting electrocatalysts, we will discuss how surface oxidation and metal dissolution affect catalytic activity of the surfaces towards OER. These studies are geared towards developing a unified picture of metal dissolution across metal oxides and understanding their activity-stability-morphology relationships.

Theoretical insights into activity-stability relationships of transition metal based electrocatalysts

2019 Fall National Meeting

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