甲醛在FeS2(100)完整与S-缺陷表面吸附的理论研究

摘要

The adsorption of HCHO molecules on perfect and S-deficient FeS2(100) surfaces was studied with a periodic slab model by Perdue-Burke-Ernzerhof approach of General Gradient Approximation within the framework of the density functional theory. The calculated results show that HCHO reacted with both surfaces through the O atom. HCHO adsorbed aslant on the Fe-top site on the perfect surface, while there were two stable structures for HCHO on the S-deficient surface, where HCHO bonded with one and two fourfold-coordinate Fe cations, respectively. The calculation of density of states, Mulliken population, and vibrational frequencies of the adsorption systems indicated that the electrons transferred from the substrate to HCHO, and the bond of C=O was elongated and weakened.%运用密度泛函理论广义梯度近似的PBE方法结合周期平板模型,研究了HCHO分子在FeS2(100)完整与S-缺陷表面的吸附.结果表明,在两种表面上,HCHO均通过O原子与两个表面作用:稳定吸附于完整表面Fe-top位(Fe五配位);而在S-缺陷表面则存在两种稳定吸附模式,即HCHO分别与表面的一个和两个四配位Fe成键.对体系的态密度、轨道电荷布居和红外振动频率的分析发现,HCHO在吸附过程中从FeS2(100)表面获得电子,吸附后羰基振动频率发生红移,C=O键长伸长,羰基被削弱.