碳五元环拓扑缺陷的结构演化及电催化全解水机制研究

缺陷工程已成为近年来碳基催化剂的研究焦点。由于本征缺陷的不可或缺性，其对催化活性的影响不容忽视。碳本征缺陷由于价键结构的不同，通过优化该位点上的局域电子态可改善反应物种的吸附及转化，理论上应能降低反应活化能垒。针对碳拓扑缺陷，特别是碳本征五元环缺陷存在的结构演化及全解水电催化作用机制不明确等关键科学问题，本项目拟采用化学/物理裁剪法在碳框架中构筑五元环拓扑结构；利用球差矫正透射电子显微镜完成碳五元环拓扑缺陷几何构型的可视化观测，并通过综合物性分析及理论形成能计算结果，揭示其结构演化规律；探究富含五元环拓扑缺陷碳材料的全解水（HER/OER）电催化反应性，拓展其电催化功能及应用；最后，利用密度泛函理论对本征五元环缺陷的电子结构、吸附能及反应吉布斯自由能进行计算，分析其催化作用机制。研究成果将有助于人们更好地认识碳本征五元环拓扑缺陷的结构演化规律，并深入理解其在全解水中的反应活性及电催化机理。

Defect engineering has become the current research focus of carbon-based catalysts. Due to the indispensability of intrinsic defects, their effect on the catalytic activity cannot be ignored. Topological defects with different bonding structure can effectively optimize the local electronic state, improve the adsorption and conversion of reactive species, thus reducing the activation energy barrier theoratically. In view of the unclear structural evolution and electrocatalytic mechanism of overall water splitting for topological defects, especially intrinsic pentagon defects, this project intends to adopt a chemical/physical tailoring methodto construct pentagonal topological structures into the carbon framework. The visual observation of the geometric configuration is completed using spherical aberration-corrected transmission electron microscope, and the physical characteristic analysis and theoretical formation energy are used to infer the structural evolution rule of pentagon defects. It also explores the catalytic reactivity of pentagon defect-rich carbon nanomaterials in overall water splitting (HER/OER) to expand their catalytic functions. Finally, density functional theory is used to analyze the electronic structure, adsorption energy and Gibbs free energy of intrinsic pentagon defects in order to understand their catalytic mechanism. The research results will be helpful to understand the structural evolution law of the intrinsic pentagon defects, and their activity contribution and electrocatalytic mechanism in overall water splitting.