Abstract
The electrical double layer differential capacity has been measured by single pulse technique on single crystal gold electrodes exposing the (100) and (110) crystal plane in 
between about −0.9v (15 ma/cm2 maximum cathodic current) and +1.4v vs. SCE. A capacity maximum at +0.9 to + 1.3v, depending on concentration, is attributed to"oxygen" adsorption. This showed strong hysteresis, the corresponding desorption peaks being as much as 500 mv more negative. Some evidence for adsorption of a second "oxygen" species is presented. A maximum occurring at +0.4v has been ascribed to slight specific 
adsorption. A "hydrogen" adsorption peak is observed only on the (100) electrode at −0.2v. The complete absence of a profile during actual H2 evolution is taken as evidence that recombination of H atoms is not the rate‐determining step. A capacity minimum appears at the (110) electrode in 
and between two small maxima at the (100) electrode at −0.05v. These minima have been tentatively identified as the zero point of charge. The difference of 50 mv is reflected in an equal difference in the oxygen adsorption peaks. The zero point of charge potentials agrees satisfactorily with values interpolated from work function data.