Atomically ordered intermetallic nanoparticles are promising for catalytic applications but are difficult to produce because the high-temperature annealing required for atom ordering inevitably accelerates metal sintering that leads to larger crystallites. We prepared platinum intermetallics with an average particle size of <5 nanometers on porous sulfur-doped carbon supports, on which the strong interaction between platinum and sulfur suppresses metal sintering up to 1000°C. We synthesized intermetallic libraries of small nanoparticles consisting of 46 combinations of platinum with 16 other metal elements and used them to study the dependence of electrocatalytic oxygen-reduction reaction activity on alloy composition and platinum skin strain. The intermetallic libraries are highly mass efficient in proton-exchange-membrane fuel cells and could achieve high activities of 1.3 to 1.8 amperes per milligram of platinum at 0.9 volts.

中文翻译：

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用于燃料电池的铂金属间化合物纳米颗粒催化剂的硫锚定合成

原子有序的金属间化合物纳米粒子有望用于催化应用，但难以生产，因为原子有序所需的高温退火不可避免地会加速金属烧结，从而导致更大的微晶。我们在多孔硫掺杂碳载体上制备了平均粒径 <5 纳米的铂金属间化合物，铂和硫之间的强相互作用抑制了高达 1000°C 的金属烧结。我们合成了由 46 种铂与 16 种其他金属元素组合组成的小纳米粒子的金属间化合物库，并用它们来研究电催化氧还原反应活性对合金成分和铂表皮应变的依赖性。