To describe the properties of catalyst material for her, both the electrocatalytic and engineering aspects of catalyst application are necessary. The possible reasons for the change in catalytic activity were shown for the different selected catalysts used for the alkaline type of electrolysis. As an example, the properties of Raney nickel and its alloys were analysed. It was shown that the reasons for the deterioration of the catalyst activity may be changing of the reaction mechanism, deposition of trace metals, dissolution of the catalyst components.