The utility model relates to the technical field of electrolyzers, and discloses an electrolyzer taking an air
electrode as a
cathode, which comprises an electrolytic bath body, an electrolytic
tin ingot block is arranged in the electrolytic bath body, the electrolytic
tin ingot block is electrically connected with a positive
electrode of a
direct current power supply through a first
copper wire, and a group of vertical through holes are arranged on the electrolytic
tin ingot block. The air
electrode is rolled into a cylinder shape and placed in the through hole, the top of the air electrode is exposed above the electrolytic tin ingot and electrically connected with the negative electrode of the direct-current power source through a second
copper wire, and the bottom of the air electrode is flush with the bottom of the electrolytic tin ingot. The air electrode is used as the
cathode, the
cathode does not generate
hydrogen, so that the device is more energy-saving, environment-friendly and safe, the
oxygen reaction priority of the cathode is higher than the
side reaction generated by
sponge tin, and the generation of the
sponge tin is greatly reduced.