System for nitrogen and phosphorus recovery and preparation method of gas diffusion electrode

The invention provides a system for nitrogen and phosphorus recovery and a preparation method of a gas diffusion electrode, and the method comprises the following steps: firstly, preparing an oxygen reduction catalyst: treating cobalt nitrate, carbon black and 2-methylimidazole to obtain the oxygen reduction catalyst CB-ZIF-900; then loading the prepared catalyst on a copper-based body fluid in a spraying manner, then carrying out cold pressing, spraying PTFE emulsion on the surface of a catalyst layer, and carrying out annealing treatment, so that the surface of the gas diffusion electrode has a hydrophobic characteristic; according to the invention, a magnesium air fuel cell technology and a membrane steam stripping technology are combined to construct a composite nitrogen and phosphorus resource recovery system, and nitrogen and phosphorus resources are recovered from urine wastewater. The cathode and the anode of the device not only keep the advantages of Mg < 2 + > and alkali source output of the magnesi