▎ 摘　　要

NOVELTY - A copper catalyst for producing ethanol, includes metallic copper as main portion, and utilizes high surface energy stepped sites as active sites, where the longitudinal depth and number of the high surface energy stepped sites are controllably adjusted, and the longitudinal depth is 0.1-20 nm. USE - Copper catalyst for producing ethanol by carbon dioxide electroreduction (claimed), used in electrochemistry applications. ADVANTAGE - The crystal planes are reorganized into high surface energy Cu(110), Cu(210), and Cu(310) crystal planes, thereby showing the atomic arrangement characteristic of high surface energy. The copper catalyst with periodic stepped surface has lower coupling barrier and better ethanol reaction path, thereby realizing electrocatalytic carbon dioxide reduction to prepare ethanol fuel with high selectivity. The method enables performing electro-catalysis carbon dioxide reduction to prepare ethanol fuel, and is economical and easy to produce in large scale. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: 1. preparation method of copper catalyst for producing ethanol by carbon dioxide electroreduction, which involves (S1) pickling polished copper to remove surface impurities and oxide layers, (S2) using plasma enhanced vapor chemical deposition method to grow vertical graphene of different sizes on the copper surface after pickling, and controlling the copper surface to generate different vertical depths and different numbers of high surface energy stepped sites according to the thermal expansion energy difference between the two, and (S3) adding copper growing vertical graphene to electrolyte for electrolysis, peeling off the graphene attached to the surface, rinsing with deionized water and drying with nitrogen; and 2. application of copper catalysts for carbon dioxide electroreduction to ethanol, which involves using copper containing controllable high surface energy stepped active sites as catalyst and working electrode, in electrolyte, where the copper catalyst catalyzes the reduction of carbon dioxide to ethanol, by (i) adding copper catalyst containing controllable high surface energy step-like active sites to certain concentration of cathode electrolyte, (ii) sealing the electrolytic cell, passing carbon dioxide to cathode electrolytic cell to pre-saturate the electrolyte and activate the working electrode, and (iii) activating, under condition that carbon dioxide is continuously fed.