To figure out the different electrochemical performance of ordered and disordered nano-intermetallic catalysts and their mechanisms, we successfully synthesized AuCu/C electrocatalysts through a modified co-precipitation method and obtained their ordered and disordered structure at different temperatures. A systematic comparison between the ordered and disordered AuCu/C with the similar composition, particle size, valence state was conducted. The AuCu/C nanoparticles with better structure-ordering showed superior catalytic performance for the oxygen reduction reaction (ORR) than the disordered ones. It was also observed that the disordered AuCu/C tended to form a Cu-shell structure which was believed to be detrimental to ORR electrocatalysis. (c) 2017 The Electrochemical Society. All rights reserved.