Abstract:

The electrochemical conversion of nitrogen (N₂) and water (H₂O) into ammonia (NH₃) under normal temperature and pressure conditions is a green and environmentally friendly method of ammonia synthesis. However, because N₂ has a very high chemical inertness, an electrocatalyst must be used to accelerate the kinetic process of the reaction. In this paper, we use density functional theory calculations to reveal that AuP₂, a new type of two-dimensional inorganic material, has good catalytic activity for the electrochemical reduction of N₂ to NH₃. In the two-dimensional AuP₂ material, significant charge transfer occurs between Au and P atoms due to the difference in electronegativity, so that positively charged P can be used as an active site to promote nitrogen reduction. Our calculations show that the rate-determining step of the entire reaction is the process of generating ^*NNH from N₂ with a limiting voltage of 1.2 V, and the catalytic activity can be comparable to some metal catalysts. This work provides new ideas for the design of high-efficiency nitrogen reduction electrocatalysts.

Key words: two-dimensional materials, AuP₂, electrocatalysis, nitrogen reduction reaction, density functional theory calculations

摘要：

通过电化学反应将氮气（N₂）和水（H₂O）在常温常压的条件下转化为氨气（NH₃）是一种绿色环保的合成氨方法。但由于N₂具有非常高的化学惰性，必须借助电催化剂来加速反应的动力学过程。通过密度泛函理论计算揭示出新型二维无机材料AuP₂对N₂电化学还原制NH₃具有很好的催化活性。在二维AuP₂材料中，Au与P之间由于电负性差异发生显著的电荷转移，使带有正电荷的P可作为活性位点促进氮还原。计算表明整个反应的速控步是N₂生成^*NNH的过程，限制电压为1.2 V，催化活性可以跟部分金属催化剂相媲美。为设计高效氮还原电催化剂提供了新的思路。

关键词: 二维材料, AuP₂, 电催化, 氮还原, 密度泛函理论计算