Oxygen gas diffusion cathode, electrolytic cell employing same, method of producing chlorine gas and method of producing sodium hydroxide

An oxygen gas diffusion cathode for brine electrolysis comprising:

• a porous electro-conductive substrate made of carbon material;
• a gas diffusion layer containing hydrophobic resin and electro-conductive powders made of carbon powders, and a reaction layer containing electro-conductive powders made of carbon powders, a hydrophilic catalyst consisting of at least one noble metal selected from the group consisting of silver, platinum and palladium, and hydrophobic resin, both of which are positioned on one surface of the above electro-conductive substrate;
• and
• an electro-conductive layer containing metal powders consisting of at least one noble metal selected from the group consisting of silver, platinum and palladium and hydrophobic resin and positioned on a surface opposite to the above one surface of the electro-conductive substrate.