Porous clusters of silver powder promoted by zirconium oxide for use as a catalyst in gas diffusion electrodes, and uses thereof

An air electrode comprising a catalyst comprising a plurality of porous clusters of silver particles, each cluster including a plurality of primary particles of silver and crystalline particles of zirconium oxide (ZrO), wherein at least a portion of said crystalline particles of ZrOis located in pores formed by a surface of said plurality of primary particles; a water-repellant polymer; a silver-coated current collector; and a porous hydrophobic film, wherein said catalyst, said water-repellent polymer and said current collector are located on a single broad face of said porous hydrophobic film.