Senthamaraikannan Thillai Govindaraja, Kaliaperumal Selvaraj, Krishnamurty Sailaja
Department of Environmental Engineering, Chungbuk National University, Cheongju, Korea.
Nano and Computational Material Lab, Catalysis Division, CSIR-National Chemical Laboratory, Pune, India.
Front Chem. 2021 Sep 8;9:733422. doi: 10.3389/fchem.2021.733422. eCollection 2021.
Using the periodic density functional theory-based methodology, we propose a potential catalytic system for dinitrogen activation, viz., single metal atoms (Mo, Fe, and V) supported on graphene-based sheets. Graphene-based sheets show an excellent potential toward the anchoring of single atoms on them (Mo, Fe, and V) with adsorption energies ranging between 1.048 and 10.893 eV. Factors such as defects and BN doping are noted to enhance the adsorption energies of single metal atoms on the support. The adsorption of a dinitrogen molecule on metal atom-anchored graphene-based supports is seen to be highly favorable, ranging between 0.620 and 2.278 eV. The adsorption is driven through a direct hybridization between the orbitals of the metal atom (Mo, Fe, and V) on the support and the orbital of the molecular nitrogen. Noticeably, BN-doped graphene supporting a single metal atom (Mo, Fe, and V) activates the N molecule with a red shift in the N-N stretching frequency (1,597 cm as compared to 2,330 cm in the free N molecule). This red shift is corroborated by an increase in the N-N bond length (1.23 Å from 1.09 Å) and charge transfer to an N molecule from the catalyst.
使用基于周期性密度泛函理论的方法，我们提出了一种用于双氮活化的潜在催化体系，即负载在石墨烯基片上的单金属原子（Mo、Fe和V）。石墨烯基片对其上的单原子（Mo、Fe和V）具有优异的锚定潜力，吸附能在1.048至10.893电子伏特之间。缺陷和BN掺杂等因素被认为可提高单金属原子在载体上的吸附能。双氮分子在金属原子锚定的石墨烯基载体上的吸附被认为是非常有利的，范围在0.620至2.278电子伏特之间。吸附是通过载体上金属原子（Mo、Fe和V）的轨道与分子氮的轨道之间的直接杂化来驱动的。值得注意的是，负载单金属原子（Mo、Fe和V）的BN掺杂石墨烯使N分子活化，N-N伸缩频率发生红移（与自由N分子中的2330厘米相比为1597厘米）。这种红移通过N-N键长从1.09埃增加到1.23埃以及电荷从催化剂转移到N分子得到证实。
