Lv Xiaojing, Zhang Shujie, Wang Junkai, Wang Man, Shan Jingyi, Zhou Shuaikang
School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo, 454003, China.
School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo, 454003, China; The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan, 430081, China.
J Mol Graph Model. 2022 Jan;110:108056. doi: 10.1016/j.jmgm.2021.108056. Epub 2021 Oct 23.
Methane is not only the main cause of coal mine accidents but also a contributor to global warming, meanwhile, it is clean energy. It is necessary to find an advanced material which can capture methane efficiently for its utilization. In this paper, the adsorption of CH gas molecules on NbCT(T = O, F, Cl, OH) is studied by first-principles calculation. The results indicate that the adsorption of CH on NbCT(T = O, F, Cl, OH) is weak, and the adsorption of CH on NbC(OH) is the best. The calculation results of binding energy and cohesive energy show that NbCO has the best stability. The adsorption behavior of CH on NbCO under charge control is further studied. With the increase of negative charge state in the system, the adsorption of CH on NbCO is significantly enhanced, from physical adsorption to chemical adsorption; when the charge state of the system is greater than or equal to -2, NbCO can capture CH effectively, and the charges transferred from NbCO to CH mainly come from Nb atom. After the removal of the extra charge, the adsorption of CH on NbCO becomes weak and returns to physical adsorption state; CH gas molecules are easy to desorb. Therefore, NbCO can capture and release CH molecules by regulating the charge state of NbCO, and NbCO is expected to become an excellent candidate material for CH capture/release.
甲烷不仅是煤矿事故的主要成因，也是全球变暖的促成因素，同时它还是清洁能源。有必要找到一种能高效捕获甲烷以用于其利用的先进材料。本文通过第一性原理计算研究了CH气体分子在NbCT（T = O、F、Cl、OH）上的吸附情况。结果表明，CH在NbCT（T = O、F、Cl、OH）上的吸附较弱，且CH在NbC(OH)上的吸附效果最佳。结合能和内聚能的计算结果表明NbCO具有最佳稳定性。进一步研究了电荷控制下CH在NbCO上的吸附行为。随着体系中负电荷状态的增加，CH在NbCO上的吸附显著增强，从物理吸附转变为化学吸附；当体系电荷状态大于或等于 -2时，NbCO能有效捕获CH，且从NbCO转移到CH的电荷主要来自Nb原子。去除额外电荷后，CH在NbCO上的吸附变弱并回到物理吸附状态；CH气体分子易于解吸。因此，NbCO可通过调节自身电荷状态来捕获和释放CH分子，NbCO有望成为CH捕获/释放的优异候选材料。
