High-temperature oxide electrocatalysts facilitate a variety of reactions that are key to reversible interconversion of electrical and chemical energy, including O2 reduction, H2/H2O redox, and CO/CO2 redox. A universal challenge facing development of these materials is a lack of fundamental understanding of physical and chemical rates at local length scales (10-50 nm). Our work seeks to better understand the interplay of thermodynamic, kinetic, and transport properties at local length scales in determining overall rates in these materials.