▎ 摘　　要

NOVELTY - Metal colloid catalyst comprises a metal colloid and a carbon material carrier. The metal colloid is a colloidal nanoparticle solution formed by mixing a multi-metal solution and an alkali solution. The multi-metal solution comprises a combination of water-soluble or acid-soluble compounds of at least two metals in transition metals comprising nickel, iron, cobalt, copper, manganese and chromium. The alkaline solution comprises at least one of aqueous ammonia, potassium hydroxide and/or sodium hydroxide. USE - The metal colloid catalyst is useful in electrolyzing water to produce hydrogen or preparing a metal zinc-air battery (all claimed) and oxygen evolution reaction under alkaline conditions. ADVANTAGE - The metal colloid catalyst: has an ultra-high activity bifunctional (ORR and OER) catalyst; and preparation method is environmentally-friendly, economical and economical with excellent reproducibility and scalability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: Preparing metal colloid catalyst, comprising (i) mixing metal solution and alkali solution to obtain metal colloid solution; and (ii) mixing the metal colloid solution with the carbon material carrier, stirring or grinding to mixing fully to obtain mixture of the colloidal nanoparticle solution and the carbon material carrier; and Application of metal colloid catalyst comprising (a) mixing the metal colloid catalyst with a conductive agent and a bonding agent, adding deionized water and ethanol, carrying auxiliary dispersion and mixing to obtain a mixed material; and (b) pressing the mixed material into a catalyst sheet, bonding on a conductive substrate, and drying the metal colloid to obtain an electrode sheet which is directly used as an anode for electrolyzing water to produce hydrogen or as a cathode for a metal-zinc-air battery.