An experimental scheme for the analysis of electrode kinetics on solid electrolytes using a combination of pressure modulation and electrochemical impedance spectroscopy is described. The data interpretation involves two-port electrical equivalent circuits. Application to the Au/solid Na2CO3 interface reveals that only one of the two electrode processes found in the impedance spectra determines the response behavior to O-2 and CO2 partial pressure modulation. The rate-determining step is assigned to the formation of oxygen radical anions O- from molecular oxygen at the Na2CO3 covered Au surface.