School of Energy and Chemical Engineering/Center for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, South Korea.
Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, and School of Materials Science and Engineering, Jilin University, Changchun 130022, China.
Sci Adv. 2019 Nov 1;5(11):eaax8275. doi: 10.1126/sciadv.aax8275. eCollection 2019 Nov.
All quiet on the nitrogen front. The dissociation of stable diatomic nitrogen molecules (N) is one of the most challenging tasks in the scientific community and currently requires both high pressure and high temperature. Here, we demonstrate that N can be dissociated under mild conditions by cyclic strain engineering. The method can be performed at a critical reaction pressure of less than 1 bar, and the temperature of the reaction container is only 40°C. When graphite was used as a dissociated N* receptor, the normalized loading of N to C reached as high as 16.3 at/at %. Such efficient nitrogen dissociation is induced by the cyclic loading and unloading mechanical strain, which has the effect of altering the binding energy of N, facilitating adsorption in the strain-free stage and desorption in the compressive strain stage. Our finding may lead to opportunities for the direct synthesis of N-containing compounds from N.
氮气方面一片宁静。稳定双原子氮分子（N）的离解是科学界最具挑战性的任务之一，目前需要高压和高温。在这里，我们证明通过循环应变工程可以在温和的条件下使 N 离解。该方法可以在低于 1 巴的临界反应压力下进行，并且反应容器的温度仅为 40°C。当使用石墨作为离解的 N*受体时，N 到 C 的归一化负载高达 16.3 at/at%。这种高效的氮气离解是由循环加载和卸载机械应变引起的，这种应变改变了 N 的结合能，有利于在应变释放阶段吸附，在压缩应变阶段解吸。我们的发现可能为从 N 直接合成含氮化合物提供机会。
