▎ 摘　　要

NOVELTY - Metal monoatomic electrocatalyst comprises a base material, and an atomic cluster comprising metal single atom of free platinum, gold, palladium, rhodium, iridium, ruthenium, cobalt, nickel, iron, and copper, and chlorine as coordination element. USE - Used as metal monoatomic electrocatalyst. ADVANTAGE - The electrocatalyst: is suitable for material science and engineering technical field. DETAILED DESCRIPTION - Monoatomic electrocatalyst comprises a base material, and an atomic cluster represented by formula MClx loaded on the base material, where M is metal single atom of free platinum, gold, palladium, rhodium, iridium, ruthenium, cobalt, nickel, iron, and copper, chlorine as coordination element, and x is the coordination number of the chlorine element i.e. x = 0-6, and the content of single metal atom is 0.01-1 wt.%, preferably 0.1-10 wt.%. An INDEPENDENT CLAIM is also included for preparing the metal single atom electro-catalyst, comprising (i) mixing metal salt solution with base material to obtain mixed solution, where the metal salt is metal single atom M containing chlorine compound; and (ii) carrying out ultrasonic crushing treatment to the mixed solution to obtain the metal monoatomic electrocatalyst.