Electrolyzer, electrodes used therefor, and electrolysis method

An electrolyzer comprising an anode and a cathode in contact with an electrolytic solution, wherein at least one of said anode and said cathode is composed of an electric conductor having a gas permeable structure comprising a gas generating surface at which a gas is generated by electrolysis of said electrolytic solution, a plurality of through holes leading from said gas generating surface to a different surface and allowing said gas generated at the gas generating surface to selectively pass therethrough, and a gas releasing surface which is said different surface for releasing said gas supplied from said gas generating surface via said through holes, and

• at least one of a surface treatment which causes said gas generating surface to be lyophilic for said electrolytic solution and a surface treatment which causes said gas releasing surface to be lyophobic for said electrolytic solution is performed, and
• said through holes have a radius so that the pressure of said electrolytic solution is not more than Young-Laplace pressure ΔP based on the following formula;
• ΔP=−2γ cos θ/r
• wherein γ [N/m] is the surface tension of the electrolytic solution, θ [deg] is the contact angle between the at least one of said anode and said cathode and the electrolytic solution and r[m] is the radius of said through holes of said at least one of said anode and said cathode;
• and
• a gas storage unit for covering said gas releasing surface of the at least one of said anode and said cathode, and receiving said gas released from said gas releasing surface;
• wherein said electrolytic solution is molten salt containing hydrogen fluoride and a fluorine gas is generated at said anode.