功能化石墨烯负载的Au纳米合金的制备及其LSPR增强的醇氧化酯化机理研究

The gold nanoparticles exhibiting localized surface plasmon resonance (LSPR) effect have been recognized as a new class of efficient and green photocatalyst for the alcohols selective aerobic oxidative esterification reaction and thus have attracted widespread attention. However, esters synthesis with high efficiency and high selectivity remains a great challenge. We propose to design and prepare functionalized graphene supported Au nano-alloy which is composed of gold and a transition metal with different work function. The systematic study will be conducted on the photocatalytic performance of the selective catalytic oxidation of alcohols to esters and revealing the reaction mechanism. The transporting interface of LSPR-induced hot electrons and the structure, composition, size of alloy nanoparticles will be optimized by controlling the types and number of groups on the functionalized graphene surface, resulting in the corresponding elaborated construct of the light-adsorption sites and the active sites, and develop visible light driven photocatalyst for alcochols oxidation to esters with high activity and selectivity eventually. The research has important theoretical and practical significance for the development of green and high efficiency catalytic system for alcohols catalytic oxidation to esters.

采用局域表面等离子体共振（LSPR）效应的Au纳米颗粒在可见光下催化醇一步选择性氧化合成酯类化合物因其原子利用率高、绿色环保而引起人们广泛关注。然而，实现醇高效高选择性合成酯类化合物仍具有很大的挑战性。本项目提出将具有LSPR效应的Au与功函数不同的另一组分金属合成纳米合金颗粒并负载于功能化石墨烯表面，系统研究其光催化醇选择性氧化合成酯类化合物的反应性能并揭示反应机理。研究将通过控制石墨烯表面共价键修饰来优化光生电子的传输界面和Au纳米合金的组成、结构、尺寸，相应地精细构筑吸光位和活性位，最终可见光驱动的醇高效高选择性氧化合成酯类化合物的催化剂。本项目的开展对于开发高效、绿色的醇选择性氧化催化体系具有重要的理论价值和实际意义。

醇一步选择性氧化酯化是合成酯类化合物的重要途经。基于可见光下局域表面等离子共振效应的负载型Au纳米颗粒光催化剂具有反应条件温和、绿色环保、对不同醇类普适性强等特点。然而依然面临着光量子产率低和产物中酯选择性差的难题。本项目采用载体缺陷工程和合金化2种方法调控Au表面电子状态，提高光电子能级使之与醇的LUMO轨道能级相匹配，调控活性中心对中间产物醛的吸附能提高酯的选择性。本项目取得的进展将促进负载型金纳米合金光催化的应用研究，加深对金属-载体协同作用和醇选择性氧化酯化反应机理等方面的科学认识，为从纳米尺度上设计高活性和高选择性醇一步选择性氧化酯化新型Au基金属光催化剂提供新思路。