Nano-Intermetallic AuCu sub(3) Catalyst for Oxygen Reduction Reaction: Performance and Mechanism

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 10; no. 13; pp. 2662 - 2669
• Main Authors: Zhang, Nanlin, Chen, Xin, Lu, Yuanjun, An, Li, Li, Xiang, Xia, Dingguo, Zhang, Ze, Li, Jixue
• Format: Journal Article
• Language: English
• Published: 01.07.2014
• Subjects: Catalysis; Catalysts; Copper; Durability; Gold; Methyl alcohol; Nanostructure; Surface chemistry
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201400068

This paper introduces a new approach for catalyst design using the non-precious metal Cu as one of the catalytic active centers. This differs from previous studies that considered precious metals to be responsible for the catalytic reaction in precious alloys. Intermetallic AuCu sub(3)/C nanoparticles with a diameter of 3 nm were developed for the first time, with uniform dispersion and a narrow size distribution. The ca. 3 nm as-synthesised AuCu sub(3)/C showed superior catalytic performance for oxygen reduction reactions (ORR) in alkaline solutions, with comparable half-wave potential and 1.5 times mass current density of commercial Pt/C at 0.80 V (vs. reversible hydrogen electrode (RHE)). The advanced catalytic activities are mainly attributed to the synergetic effects of electro-active atomic Au and Cu on the particle surface, in which Cu helps to activate the O sub(2) molecule and Au benefits OH super(-) desorption. The excellent durability and methanol tolerance exhibited in alkaline solutions provide another advantage for AuCu sub(3)/C to be considered as a potential alternative cathode catalyst in alkaline fuel cells. Au-segregated intermetallic AuCu sub(3)/C nano-particles with uniform dispersion and narrow size distribution around 3 nm are reported, which have excellent catalytic performance for ORR in alkaline solution, excellent durability as well as methanol tolerance activities. The enhanced activities mainly result from the synergetic effects between electroactive Au and Cu atoms on the particle surface: Cu activates O sub(2) adsorption, and Au promotes OH super(-) desorption.