The electrochemical nitrogen reduction reaction (NRR) is a key process for the energy transition. Transition metal atoms atomically dispersed on a solid support represent a promising approach to the design of new catalytic materials. The interest for single‐ (SACs) and dual‐atom catalysts (DACs) is steadily growing. In general, DACs are considered more active than SACs for NRR. In this work, the complex chemistry behind NRR is investigated on a set of SACs and DACs by means of density functional theory (DFT) calculations. The results indicate that self‐interaction corrected exchange‐correlation functionals must be adopted, at variance with several studies in the literature. Furthermore, it is not possible to extrapolate results obtained on conventional extended catalytic surfaces to SACs and DACs, due to a richer scenario of possible reaction paths. In general, the results show a positive effect on the catalytic activity moving from 3d to 5d metals, and from SACs and DACs. However, if the two effects work together, that is, 5d metals in DACs, the reaction intermediates may be too strongly bound, thus resulting in reduced catalytic activity. In this respect, the fact that DACs are expected to be superior to SACs in NRR is not always verified.

中文翻译：

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从头开始热力学的电化学氮还原反应：单原子催化剂与双原子催化剂


电化学氮还原反应（NRR）是能量转换的关键过程。以原子方式分散在固体载体上的过渡金属原子代表了设计新型催化材料的一种有前途的方法。人们对单原子催化剂（SAC）和双原子催化剂（DAC）的兴趣正在稳步增长。一般来说，对于 NRR，DAC 被认为比 SAC 更活跃。在这项工作中，通过密度泛函理论 (DFT) 计算，在一组 SAC 和 DAC 上研究了 NRR 背后的复杂化学。结果表明，必须采用自相互作用校正交换相关函数，这与文献中的几项研究不同。此外，由于可能的反应路径更丰富，因此不可能将传统扩展催化表面上获得的结果外推到 SAC 和 DAC。总的来说，结果显示对从 3d 金属到 5d 金属以及从 SAC 和 DAC 的催化活性产生积极影响。然而，如果两种效应共同作用，即DAC中的5d​​金属，反应中间体可能结合得太强，从而导致催化活性降低。在这方面，DAC 预计在 NRR 方面优于 SAC 的事实并不总是得到验证。