METHOD FOR PRODUCING CORE-SHELL CATALYST

A core-shell catalyst with high platinum mass activity for a short period of time. The method for producing a core-shell catalyst may comprise a core containing palladium and a shell containing platinum and coating the core, the method comprising: a step of preparing a copper-coated palladium-containing particle dispersion in which copper-coated palladium-containing particles are dispersed, the particles being palladium-containing particles coated with copper; a step of preparing a platinum ion-containing solution; a step of preparing a microreactor; and a substitution step of forming the shell by substituting the copper on the copper-coated palladium-containing particle surface with platinum by mixing the copper-coated palladium-containing particle dispersion and the platinum ion-containing solution in the microreactor.