氧分子在黄铁矿和方铅矿表面的吸附

摘要

The adsorption of oxygen molecule (O2) on the pyrite and galena surfaces was studied using density functional theory (DFT). The calculated results show that the surface relaxation of pyrite and galena is small. O2 dissociates after adsorption on the pyrite and galena surfaces, and the adsorption energy of O2 on pyrite is much lower than that on the galena. On the pyrite surface, oxygen atom (O) bonds with sulfur (S) and iron (Fe) atoms and the electrons are transferred from Fe and S atoms to O, and the reactions are mainly S 3p, O 2p and Fe 3d states involved, forming the d?p back bonding between Fe and O. While on the galena surface, oxygen atom only bonds with sulfur atom, and the reactions are mainly S 3p, O 2p and Pb 6p states involved, without forming d椈p back bonding. The bonded Fe and O atoms are spin-polarized after the adsorption of O2, while the galena surface atoms and adsorbed O atom are still low-spin states.%采用密度泛函理论对氧分子在黄铁矿和方铅矿表面的吸附进行研究.计算结果表明:黄铁矿和方铅矿表面经历了较小的弛豫:氧分子在黄铁矿和方铅矿表面都呈解离吸附状态,且在黄铁矿表面的吸附能远低于在方铅矿表面的吸附能；在黄铁矿表面上,氧原子分别与铁原子和硫原子键合,电子由铁原子和硫原子转移到氧原子上,主要由硫的3p态、氧的2p态和铁的3d态参与反应,铁与氧之间形成d→p反馈键,而在方铅矿表面上,氧原子只与硫原子键合,主要由硫的3p态、氧的2p态和铅的6p态参与反应,未形成反馈键:氧吸附后黄铁矿表面产生键合的铁原子和氧原子都产生自旋现象,而方铅矿表面原子及吸附的氧原子仍然是低自旋态的.