The electrochemical synthesis of nitrates through nitrogen oxidation reactions (NOR) faces challenges due to the chemical stability of N₂ and the complexity of its electron transfer mechanisms. Here, we report the enhancement of the NOR via Al doping into Co₃O₄. This doping modifies the electronic structure of Co₃O₄, particularly by increasing the e_g orbital occupation, which effectively activates N₂. Our experimental results, corroborated by density functional theory (DFT) calculations, reveal that Al doping shortens Co–N bond lengths and elongates the N≡N bond, thereby enhancing N₂ polarization. The altered material, Al–Co₃O₄, delivers a nitrate yield of 78.45 μg·h^–1·mg_cat^–1 with a Faradaic efficiency of 11.91%. These improvements are attributed to an optimized electron configuration and enhanced adsorption characteristics due to the modified orbital occupancy. Our study highlights the crucial role of orbital engineering in enhancing electrocatalyst efficiency for nitrogen activation, offering a promising route for the advancement of NOR technology.

中文翻译：

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解码 eg 轨道占据率在 Co 位点中的作用：对电催化硝酸盐合成的增强 N2 活化的机理见解


由于 N₂ 的化学稳定性及其电子转移机制的复杂性，通过氮氧化反应 （NOR） 电化学合成硝酸盐面临挑战。在这里，我们报告了通过将 Al 掺杂到 Co₃O₄ 中来提高 NOR。这种掺杂改变了 Co₃O₄ 的电子结构，特别是通过增加 e_g 轨道占据，从而有效地激活 N₂。我们的实验结果得到了密度泛函理论 （DFT） 计算的证实，表明 Al 掺杂缩短了 Co-N 键的长度并延长了 N≡N 键，从而增强了 N₂ 极化。改变的材料 Al-Co₃O₄ 的硝酸盐产率为 78.45 μg·h^–1·mg_cat^–1，法拉第效率为 11.91%。这些改进归因于优化的电子构型和由于改进的轨道占用而增强的吸附特性。我们的研究强调了轨道工程在提高电催化剂氮活化效率方面的关键作用，为 NOR 技术的发展提供了一条有前途的途径。