Bimetallic nanoparticles with tailored structures constitute a desirable model system for catalysts, as crucial factors such as geometric and electronic effects can be readily controlled by tailoring the structure and alloy bonding of the catalytic site. Here we report a facile colloidal method to prepare a series of platinum–gold (PtAu) nanoparticles with tailored surface structures and particle diameters on the order of 7 nm. Samples with low Pt content, particularly Pt₄Au₉₆, exhibited unprecedented electrocatalytic activity for the oxidation of formic acid. A high forward current density of 3.77 A mg_Pt⁻¹ was observed for Pt₄Au₉₆, a value two orders of magnitude greater than those observed for core–shell structured Pt₇₈Au₂₂ and a commercial Pt nanocatalyst. Extensive structural characterization and theoretical density functional theory simulations of the best-performing catalysts revealed densely packed single-atom Pt surface sites surrounded by Au atoms, which suggests that their superior catalytic activity and selectivity could be attributed to the unique structural and alloy-bonding properties of these single-atomic-site catalysts.

具有定制结构的双金属纳米颗粒构成了理想的催化剂模型系统，因为关键的因素（例如几何和电子效应）可以通过定制催化位点的结构和合金键很容易地控制。在这里，我们报告了一种简便的胶体方法，以制备一系列具有定制表面结构和粒径约7 nm的铂金（PtAu）纳米颗粒。Pt含量低的样品，特别是Pt ₄ Au ₉₆，对甲酸的氧化表现出空前的电催化活性。对于Pt ₄ Au ₉₆，观察到3.77 A mg _Pt ^-1的高正向电流密度，其值比核壳结构的Pt ₇₈ Au ₂₂和市售Pt纳米催化剂所观察到的值大两个数量级。对性能最佳的催化剂进行了广泛的结构表征和理论密度泛函理论模拟，结果发现被Au原子包围的密集单原子Pt表面位点表明，其优越的催化活性和选择性可归因于独特的结构和合金键合特性这些单原子中心催化剂。