Abstract PdxAuy loaded reduced graphene oxide on nickel foam(PAGN) were synthesized in a simple and green way of spontaneous reduction. Different characterization methods, including XRD, Raman spectra, SEM, TEM and XPS, were used to investigated the chemical composition, morphology and structure of the composites. The catalytic activity of the prepared electrodes were estimated by means of cyclic voltammetry(CV), chronoamperometry(CA), and electrochemical impedance spectroscopy(EIS). Graphene oxide was firstly reduced by Ni foam directly, and then noble metal(Pd and Au) ions were reduced by reduced graphene oxide supported on the surface of Ni substrate. By varying the palladium/gold mole ratios into 4:1, 5:1 and 6:1, the optimized P5A1GN anode with a ratio of 5:1 is obtained in terms of the best performance among all these anodes. The P5A1GN electrode exhibited respectively the maximum peak current density of 0.72 and 1.18A cm-2mg-1PdAu in methanol and ethanol electrooxidation, which only reduced by 1% and 7% after a long-term CV scanning test of 1000 cycles. The better overall performance and stability of the P5A1GN electrode in methanol and ethanol oxidation was ascribed to the improvement of graphene to the electrode properties, the optimization of Pd electronic properties tuned by Au element as well as the cocatalysis of Au.

中文翻译：

---

PdxAuy在泡沫镍（PAGN）复合材料上负载还原氧化石墨烯用于高效甲醇和乙醇电氧化

摘要 以一种简单、绿色的自发还原方式合成了负载PdxAuy 的泡沫镍（PAGN）上的还原氧化石墨烯。使用不同的表征方法，包括 XRD、拉曼光谱、SEM、TEM 和 XPS，研究了复合材料的化学成分、形貌和结构。采用循环伏安法（CV）、计时电流法（CA）和电化学阻抗谱（EIS）对制备的电极的催化活性进行了评估。氧化石墨烯首先被泡沫镍直接还原，然后被负载在镍基体表面的还原氧化石墨烯还原贵金属（Pd和Au）离子。通过将钯/金摩尔比改变为 4:1、5:1 和 6:1，就所有这些阳极中的最佳性能而言，获得了比率为 5:1 的优化 P5A1GN 阳极。P5A1GN电极在甲醇和乙醇电氧化中分别表现出0.72和1.18A cm-2mg-1PdAu的最大峰值电流密度，经过1000次循环的长期CV扫描测试后仅降低了1%和7%。P5A1GN 电极在甲醇和乙醇氧化中更好的整体性能和稳定性归因于石墨烯对电极性能的改善、由 Au 元素调节的 Pd 电子性能的优化以及 Au 的共催化。