ELECTRODE COATED WITH A CATALYST HAVING A LOW OVERVOLTAGE FOR THE RELEASE OF OXYGEN USEFUL IN PARTICULAR FOR THE ELECTROLYSIS OF WATER IN AN ALKALINE MEDIUM AND METHOD FOR ITS PREPARATION

摘要

An electrode is described, consisting of a metal support acting as current collector (plate, cloth or grid, for example of expanded nickel) covered with a layer of finely divided nickel whose specific surface is, for example, from 10 to 80 m2/g and in which the pore size is, for example, from 2 to 10 nm, for example by spraying onto its surface molten particles of a nickel-aluminium alloy by means of a plasma torch, and then eroding the aluminium from this alloy with an alkaline solution (Raney nickel), and then with a fine layer of an oxide containing cobalt, deposited (or formed) in the pores of the divided nickel layer (for example by impregnation with a solution containing at least one cobalt salt, followed by drying and calcining). This electrode is advantageously employed as anode, in particular for the electrolysis of water in an alkaline medium: it has a reduced overvoltage for the release of oxygen.