Constructing nitrogen (N₂) adsorption and activation sites on semiconductors is the key to achieving efficient N₂ photofixation. Herein, Mn–W dual-metal sites on WO₃ are designed toward efficient N₂ photoreduction via controlled Mn doping. Impressively, the optimal 2.3% Mn-doped WO₃ (Mn-WO₃) exhibits a remarkable ammonia (NH₃) production rate of 425 µmol g_cat.⁻¹ h⁻¹, representing the best catalytic performance among the ever-reported tungsten oxide-based photocatalysts for N₂ fixation. Quasi in situ synchrotron radiation X-ray spectroscopy directly identifies that the Mn–W dual-metal sites can enhance the polarization of the adsorbed N₂, which is beneficial to the N₂ activation. Further theoretical calculations reveal that the increased polarization is originated from the electron back-donation into the antibonding orbitals of the adsorbed N₂, hence lowering the reaction energy barrier toward the N₂ photofixation. The concept of dual sites construction for inert molecule activation offers a powerful platform toward rational design of highly efficient catalysts for nitrogen fixation and beyond.

中文翻译：

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双金属位点促进氮分子的极化以实现有效的氮光固定

在半导体上构建氮 (N ₂ ) 吸附和活化位点是实现高效 N ₂光固定的关键。在此，WO ₃上的Mn-W 双金属位点旨在通过受控的Mn 掺杂实现高效的N _{2 光}还原。令人印象深刻的是，最佳的 2.3% Mn 掺杂 WO ₃ (Mn-WO ₃ ) 表现出显着的氨 (NH ₃ ) 生成速率为 425 µmol g _cat。^-1 h ^-1，代表了以往报道的氧化钨基光催化剂中对 N ₂的最佳催化性能固定。准原位同步辐射X射线光谱直接确定Mn-W双金属位点可以增强吸附N ₂的极化，有利于N ₂活化。进一步的理论计算表明，增加的极化源于电子回馈到吸附的 N ₂的反键轨道，从而降低了朝向 N ₂光固定的反应能垒。惰性分子活化的双位点构建概念为合理设计用于固氮及其他用途的高效催化剂提供了强大的平台。