▎ 摘　　要

NOVELTY - Producing electrocatalyst, comprises electrodepositing a transition metal oxide on the surface of the conductive nanoparticle support, and doping nitrogen on the transition metal oxide electrodeposited on the surface of the conductive nanoparticle support. USE - The method is useful for producing electrocatalyst used for oxygen generation or oxygen reduction. ADVANTAGE - The electrocatalyst has excellent conductivity and stability and high activity in both oxygen generation reaction and oxygen reduction reaction in an alkaline electrolyte can be prepared. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: electrocatalyst, comprising conductive nanoparticle support, and multiple nitrogen-doped transition metal oxide nanoparticles distributed on the surface of the conductive nanoparticle support; metal-air battery comprising electrocatalyst; and water electrolysis-fuel cell comprising electrocatalyst.