The synthesis of surface composition-tunable Pt-based octahedral nanoalloys is key to unravel the structure-property relationship in fuel cells. Herein, we report a facile route to prepare composition-tunable PtCu octahedral nanoalloys by using halogen ions (Br^- or/and I^-) as composition modulators. Among these PtCu octahedral nanoalloys, Pt₅₉Cu₄₁ octahedron exhibits the highest catalytic activity and durability in alkaline solution. The specific activity/mass activity of Pt₅₉Cu₄₁ octahedron is 20.25 mA cm^-2/3.24 A mg^-1_Pt, which is 6.64/5.3 times higher than commercial Pt black in 0.5 mol L^-1 CH₃OH, respectively. In the case of using ethanol (0.5 mol L^-1) as fuel source, Pt₅₉Cu₄₁ octahedron shows much better catalytic activity, that is 34.84 mA cm^-2/5.58 A mg^-1_Pt for specific activity/mass activity, which is 9.16/7.34 times higher than commercial Pt black, respectively. In situ Fourier transform infrared spectroscopy is employed to detect the intermediate species and products for methanol/ethanol oxidation reaction and a plausible mechanism is proposed to explain the improved activity and durability of Pt₅₉Cu₄₁ octahedron toward methanol/ethanol oxidation in alkaline medium.

表面组成可调谐的基于Pt的八面体纳米合金的合成是揭示燃料电池中结构与特性关系的关键。此，我们报告一个浅显的路线制备组合物可调PtCu八面体纳米合金通过使用卤素离子（溴^-和/或我^- ）作为组合物调节剂。在这些PtCu八面体纳米合金中，Pt ₅₉ Cu ₄₁八面体在碱性溶液中表现出最高的催化活性和耐久性。Pt ₅₉ Cu ₄₁八面体的比活/质量活度为20.25 mA cm ^-2 /3.24 A mg ^-1 _Pt，比市售Pt黑在0.5 mol L ^-1中高6.64 / 5.3倍CH ₃ OH。在使用乙醇（0.5 mol L ^-1）作为燃料源的情况下，Pt ₅₉ Cu ₄₁八面体显示出更好的催化活性，即比活度/质量活度为34.84 mA cm ^-2 /5.58 A mg ^-1 _Pt，分别是市售Pt黑的9.16 / 7.34倍。采用原位傅里叶变换红外光谱法检测甲醇/乙醇氧化反应的中间物种和产物，并提出了一种合理的机理来解释Pt ₅₉ Cu ₄₁八面体在碱性介质中对甲醇/乙醇氧化的改善的活性和耐久性。