Osmium (Os), as the cheapest platinum (Pt)-group metal, has rarely been utilized in electrocatalysis resulting from excessive adsorbability. Interface engineering can effectively regulate the electronic state to strengthen/weaken the adsorption behaviors of key intermediates, thereby enhancing the intrinsic catalytic activity. Herein, theoretical calculations uncover the electron accumulation effect over the osmium/erlichmanite (Os/OsS₂) heterointerface, accompanied by a negative shift of the d-band center. Then, the hydrogen adsorption on resultant electron-deficient Os sites effectually weakens, leading to high catalytic activity toward hydrogen evolution reaction (HER). Through a partial sulfurization strategy assisted by the eutectic salt system, the desired Os/OsS₂ heterostructure is constructed as the pH-universal HER catalyst. Owing to the rapid interfacial electron transmission, high specific activity, and favorable reaction kinetics over the heterostructure, Os/OsS₂ merely needs overpotentials of 29, 37, and 58 mV at the current density of 10 mA cm^–2 in acidic, alkaline, and neutral media, respectively, which are all comparable to commercial Pt catalysts. Impressively, the price activity of the Os/OsS₂ catalyst is 14.4 and 2.5 times higher than that of the Pt catalyst at overpotentials of 10 and 50 mV in acidic media, respectively. Thorough insight into the structure–activity relationship of electron-accumulated heterointerfaces can offer profound enlightenment for the rational design of noble metal-based catalysts.

中文翻译：

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锇/Erlichmanite异质界面上的电子积累效应用于强化pH-通用析氢

锇 (Os) 作为最便宜的铂 (Pt) 族金属，由于过度吸附而很少用于电催化。界面工程可以有效地调节电子态以增强/减弱关键中间体的吸附行为，从而提高内在催化活性。在这里，理论计算揭示了锇/erlichmanite（Os/OsS ₂）异质界面上的电子积累效应，伴随着d带中心的负移。然后，在所得缺电子Os位点上的氢吸附有效减弱，导致对析氢反应（HER）的高催化活性。通过共晶盐系统辅助的部分硫化策略，所需的 Os/OsS ₂异质结构被构建为 pH 通用 HER 催化剂。由于快速的界面电子传输、高比活性和对异质结构有利的反应动力学，Os/OsS ₂在酸性、碱性、电流密度为 10 mA cm ^-2时仅需要 29、37 和 58 mV 的过电势，和中性介质，它们都可与商业 Pt 催化剂相媲美。令人印象深刻的是，Os/OsS _{2的价格活动}在酸性介质中的过电势分别为 10 和 50 mV 时，催化剂分别是 Pt 催化剂的 14.4 和 2.5 倍。深入了解电子积聚异质界面的构效关系可为贵金属基催化剂的合理设计提供深刻启示。