Electrochemical ammonia synthesis is being actively studied as a low temperature, low pressure alternative to the Haber‐Bosch process. This work studied pure iridium as the catalyst for ammonia synthesis, following promising experimental results of Pt‐Ir alloys. The characteristics studied include bond energies, bond lengths, spin densities, and free and adsorbed vibrational frequencies for the molecules N₂, N, NH, NH₂, and NH₃. Overall, these descriptive characteristics explore the use of dispersion‐corrected density functional theory methods that can model N₂ adsorption – the key reactant for electrochemical ammonia synthesis via transition metal catalysis. Specifically, three methods were tested: hybrid B3LYP, a dispersion‐corrected form B3LYP‐D3, and semi‐empirical B97‐D3. The latter semi‐empirical method was explored to increase the accuracy obtained in vibrational analysis as well as reduce computational time. Two lattice surfaces, (111) and (100), were compared. The adsorption energies are stronger on (100) and follow the trend E_B3LYP>E_B3LYP‐D3>E_B97‐D3 on both surfaces.

中文翻译：

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比较 B3LYP 和 B97 色散校正泛函用于研究氮还原中的吸附和振动光谱

作为 Haber-Bosch 工艺的低温、低压替代品，电化学合成氨正被积极研究。在 Pt-Ir 合金的有希望的实验结果之后，这项工作研究了纯铱作为氨合成的催化剂。_{研究的特性包括分子 N 2}、N、NH、NH ₂和 NH ₃的键能、键长、自旋密度以及自由和吸附振动频率。_{总体而言，这些描述性特征探索了使用可以模拟 N 2}的色散校正密度泛函理论方法吸附——通过过渡金属催化电化学合成氨的关键反应物。具体来说，测试了三种方法：混合 B3LYP、色散校正形式 B3LYP-D3 和半经验 B97-D3。探索后一种半经验方法以提高振动分析的准确性并减少计算时间。比较了两个晶格表面（111）和（100）。吸附能在（100）处更强，并且在两个表面上都遵循 E _B3LYP >E _B3LYP-D3 >E _{B97-D3的趋势。}