High‐entropy alloy (HEA) nanoparticles hold great promise as tunable catalysts. Despite the fact that alloy formation is typically difficult in oxygen‐rich environments, we found that Pt‐Ir‐Pd‐Rh‐Ru nanoparticles can be synthesized under benign low‐temperature solvothermal conditions. In situ X‐ray scattering and transmission electron microscopy reveal the solvothermal formation mechanism of Pt‐Ir‐Pd‐Rh‐Ru nanoparticles. For the individual metal acetylacetonate precursors, formation of single metal nanoparticles takes place at temperatures spanning from ca. 150 °C for Pd to ca. 350 °C for Ir. However, for the mixture, homogenous Pt‐Ir‐Pd‐Rh‐Ru HEA nanoparticles can be obtained around 200 °C due to autocatalyzed metal reduction at the (111) facets of the forming crystallites. The autocatalytic formation mechanism suggests that many types of HEA nanocatalysts should accessible with scalable solvothermal reactions, thereby providing broad availability and tunability.

中文翻译：

---

高熵合金纳米粒子的自催化形成。

高熵合金（HEA）纳米粒子作为可调催化剂具有广阔的前景。尽管事实上在富氧环境中通常很难形成合金，但我们发现Pt-Ir-Pd-Rh-Ru纳米粒子可以在良性低温溶剂热条件下合成。原位X射线散射和透射电子显微镜揭示了Pt-Ir-Pd-Rh-Ru纳米粒子的溶剂热形成机理。对于单独的乙酰丙酮金属金属前驱体，单金属纳米颗粒的形成发生在大约200到200℃的温度范围内。Pd约为150°C。铱350°C 但是，对于该混合物，由于在形成的微晶的（111）面上的自催化金属还原，在200°C左右可以获得均匀的Pt-Ir-Pd-Rh-Ru HEA纳米颗粒。