Insight into the ordering process and ethanol oxidation performance of Au-Pt-Cu ternary alloys

Direct ethanol fuel cells (DEFCs), which have been widely recognized as nontoxic and green energy conversion devices, show attractive application prospects for liquid hydrogen-carriers, due to the higher specific energy and lower toxicity of ethanol. Pt-based catalysts are widely used in DEFCs, while their poor poisoning resistance highlights the importance of composition and structure optimization. Herein, we synthesized a series of reduced graphene oxide supported ternary alloy AuPt_1-Cu₃/rGO (x = 0-1) catalysts with excellent ethanol oxidation performance and a composition-dependent volcano plot trend of the ordering degree was observed and rationalized. The highest Pt-normalized mass activity of Au_0.8Pt_0.2Cu₃/rGO is attributed to the optimized CO binding energy according to DFT calculations. This work not only provides an efficient EOR catalyst based on ordered alloys AuPt_1-Cu₃ (x = 0-1), but also offers valuable insight into the role of a third metal in tuning the structure and function of alloys.