The electrochemical nitrogen reduction reaction (NRR) is a very efficient method for sustainable NH production under mild conditions, but it requires effective catalysts to expedite the NRR kinetics. However, the linear scaling relationships between the energies of elementary steps in NRR severely limit the rates of thermally catalysis reactions. Using density functional theory calculations, we demonstrate that these scaling relations can be circumvented by introducing hydrogen bonding and confinement field in g-CN/Ru(Rh) catalysis. Specially, the adsorption strength of key intermediate *NH can be enhanced on the g-CN/Ru(Rh) own to the formation of H···N hydrogen bonding, while the adsorption of N is weakened due to the steric confinement field of the covered g-CN, resulting a significantly decrease of the energy barrier for the potential-limiting step in g-CN/Ru(Rh) system compared that in pure Ru(Rh) surface. Moreover, the hydrogen bonding strength between g-CN and *NH increases with increasing of H atoms, which lower the energy barrier for the following protonation steps. Our results provide guidance for optimizing catalysts for application with hydrogen bonding and steric confinement.

中文翻译：

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有限空间中氢键打破NRR中的线性比例关系：g-C3N4覆盖Ru(001)体系的案例研究

电化学氮还原反应（NRR）是一种在温和条件下可持续生产NH的非常有效的方法，但它需要有效的催化剂来加速NRR动力学。然而，NRR 中基本步骤能量之间的线性比例关系严重限制了热催化反应的速率。利用密度泛函理论计算，我们证明可以通过在 g-CN/Ru(Rh) 催化中引入氢键和限制场来规避这些标度关系。特别是，由于H·N氢键的形成，关键中间体*NH在g-CN/Ru(Rh)上的吸附强度增强，而N的吸附则由于空间限制场而减弱。与纯Ru(Rh)表面相比，g-CN/Ru(Rh)体系中的势垒限制步骤的能垒显着降低。此外，g-CN和*NH之间的氢键强度随着H原子的增加而增加，这降低了后续质子化步骤的能垒。我们的结果为优化氢键和空间限制应用催化剂提供了指导。