EN
A concise review of former studies into iron catalyst using electron spectroscopy methods is presented. A model of iron catalyst's surface, the so-called double layer model is presented. On the basis of this model both a method of determining surface content of a real iron catalyst and a method of determining the rate of potassium surface diffusion were developed. A double layer model was used to interpret thermal stability loss of potassium atoms on iron surface subjected to sulphur compounds' exposure.