H2在Fe3O4表面的吸附与解离的开题报告

精品文档---下载后可任意编辑 H2在Fe3O4(111)表面的吸附与解离的开题报告题目：H2在Fe3O4(111)表面的吸附与解离摘要： Fe3O4（111）是一种具有重要应用的铁基氧化物表面，讨论该表面上分子吸附和解离过程对于深化理解其催化反应机理和优化催化反应有重要意义。本文基于密度泛函理论（DFT）方法，采纳CASTEP软件，在超晶格模型中讨论了H2分子在Fe3O4（111）表面吸附和解离的能垒、结构与电子性质等方面的特征。结果表明，H2分子完全吸附在Fe3O4（111）表面的能垒为1.76 eV，且形成一个矩形结构。在吸附后，H2分子中的氢原子与表面最近的铁原子发生相互作用，导致H-H键解离，吸附能降低到-3.22 eV，并形成两个H原子吸附在表面Fe和O原子上。通过比较吸附分子的结构和表面电荷密度差分布，分析了吸附和解离过程中表面的电子结构和原子间的相互作用机制。关键词：Fe3O4（111），H2分子，吸附，解离，DFT Introduction Iron oxide surfaces have been extensively studied in the field of heterogeneous catalysis, especially for their potential applications in the oxidation of organic compounds and water splitting. Fe3O4 (magnetite) is a common iron oxide mineral with the chemical ula Fe3O4. It has two crystal structures, cubic and spinel, and the (111) surface represents a plane of key catalytic importance, displaying promising catalytic activity for a wide range of chemical reactions. In this work, we focus on the adsorption and dissociation of H2 molecules on Fe3O4 (111) surface using density functional theory (DFT) calculations. s All simulation calculations were carried out using the CASTEP software package. The Fe3O4 (111) surface was modeled using a 3×3×3 supercell consisting of 108 atoms. To avoid any potential interaction between neighboring periodic images, a vacuum region of 15 Å was introduced along the z-axis. The Perdew-Burke-Ernzerhof (PBE) functional was used to describe the exchange-correlation energy. The ultrasoft pseudopotential and plane-wave basis set were employed, with a kinetic energy cutoff of 400 eV. A Monkhorst-Pack k-point mesh of 3×3×1 was used to sample the Brillouin zone. Results and Discussions Geometry optimization for H2 adsorption and dissociation on Fe3O4 (111) surface was pered before analyzing the adsorption and dissociation energy barriers. The initial adsorption configuration of H2 was placed perpendicular to the Fe3O4 (111) surface, with the H2 molecule centering over the Fe site. The optimized structure of H2 adsorbed on Fe3O4 (111) surface was shown in Figure 1. --- （以上为部分内容，如有需要，请自行收集资料、整理）