中文摘要：

由于不同金属之间氧化还原电势、原子半径和电负性的不同，设计和制备形貌和合金成分可控双金属合金纳米晶仍具挑战．金属欠电位沉积（UPD）诱导Cu还原合成Cu比例可达50％的八面体Pt—Cu合金纳米晶的基础上，引入正丁胺，通过其与金属的配位作用调节了Pt和Cu前驱物的还原速度，进一步将Cu的比例提高到75％．与UPD单原子层沉积类似，在该反应中每个被还原的Pt原子均有能力催化Cu厚子的还原并键合最多12个Cu原子（密堆积结构），而铜前驱物不能在Cu原子表面上直接还原，使得纳米晶体中Cu的比例最高达到75％．此外，性能研究表明PtCu3纳米晶体表现出最高的电催化活性和稳定性。

英文摘要：

In this paper, we reported a solvothermal method for the synthesis of octahedral Pt-Cu bimetallic alloy nanocrystals （NCs） with tunable composition. Inspired by the result from our previous exploration on octahedral Pt-Cu alloy NCs that Cu contents can be tuned from 10 % to 50 %, we further tuned the Cu portion from 50 % to 75 % by simply introducing n-butylamine in the reaction system. It is believed that n-butylamine plays a key role in breaking through a thermodynamic constraint in the formation of Pt-Cu alloy nanocrystals （NCs）. The synergistic effect of underpotential deposition-like Cu reduction and the different complexion abilities of amine group of n-butylamine with two metal species effectively tuned the reduction kinetics, by which each reduced Pt atom is able to catalyze reduction of more Cu atoms and be fully covered with 12 Cu atoms in the Pt-Cu alloy crystal, while Cu precursor is not able to be reduced solely and bind solely with Cu atoms, resulting in the successful tuning of Cu composition from 50 % to 75 %. In addition, we investigated the electro-catalytic activity of Pt-Cu bimetallic alloy NCs with different composition in electro-oxidation of methanol. The as-prepared PtCu3 NCs exhibit excellent electro-catalytic performance and stability in comparison with commercial Pt black and other compositional Pt-Cu alloy NCs.