Ruihan’s paper reports on the dynamics of adsorption energetics of oxygenate reaction intermediate on the surface of a calcium iridium oxide catalyst over both short and long timescales for the oxygen evolution reaction in acidic conditions. This work brings fundamental understanding to a critical aspect of surface restructuring that is prevalent in a broad range of Ir-based materials which is directly related to long-term activity and stability outcomes. We employ a highly flexible material platform Ca2IrO4 to systematically tune catalyst properties and probe responses to well-controlled reaction conditions. We use a combination of rapid cyclic voltammetry as well as both in situ and ex situ characterization techniques to elucidate the impact of oxygen intermediates on the chemical properties of iridates and highlight the importance of understanding material dynamics over a catalyst’s lifetime. Congratulations Ruihan!