Method for preparing gaseous-nitridation treated or liquid-nitridation treated core-shell catalyst

The present invention relates to a method for preparing a gaseous- or liquid-nitridation treated core-shell catalyst and, more specifically, to a method for preparing a gaseous- or liquid-nitridation treated core-shell catalyst comprising the steps of: nitridation-treating a transition metal precursor core and noble metal precursor shell particles in the presence of a gaseous nitrogen source; or forming a transition metal precursor core and noble metal precursor shell particles, by means of a liquid nitrogen source, and at the same time allowing the nitrogen source to bond with the transition metal precursor and thus allowing nitridation treatment. Therefore, the present invention allows a high nitrogen content in the core and thus enables a prepared catalyst to have excellent durability, a small average particle size and high degree of dispersion and uniformity, and thus to be suitable for the fuel cell field.