非掺杂石墨烯基无金属催化加氢作用研究及高效催化反应设计

To expedite a significant breakthrough in the present exploration of metal-free hydrogenation catalysis, deep investigation of un-doped graphene-based metal-free carbocatalysis and design of an efficient catalytic reaction is of scientific and technological importance. Using scalable, defect-laden graphene oxide as a raw material, this project systematically modulates the in-plane functionalities and edge defects, so as to produce a high-performance un-doped graphene-based metal-free carbocatalyst. A catalytic hydrogenation reaction is employed as a model reaction to probe the mechanistic relationship between the microstructure and catalytic hydrogenation performance of the un-doped graphene-based metal-free catalyst, and to deeply understand the catalytic hydrogenation reaction, further facilitating design of a high-efficiency catalytic reaction. Green chemistry and temperature-controlled ultrasonication are used to modulate the in-plane functionalities and edge defects, respectively. X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) are mainly adopted to determine the specific in-plane functionality and track its relative content. Raman spectroscopy is employed to monitor the relative concentration of edge defects. Ultraviolet-visible (UV-Vis) spectroscopy is used to in situ real-time detect the un-doped graphene-based metal-free catalytic hydrogenation reaction. Finally, combination of the structural modulation of the catalyst and optimization of the catalytic reaction conditions leads to effective design of a high-efficiency catalytic reaction. The present study of un-doped graphene-based metal-free carbocatalytic hydrogenation and design of an efficient carbocatalytic reaction open up an avenue to controllable synthesis of highly performing metal-free carbocatalysts and design of efficient catalytic reactions, and will also bring some original contributions.

深入非掺杂石墨烯基无金属催化加氢作用研究及高效催化反应设计将为突破目前石墨烯基无金属催化加氢研究瓶颈发挥积极作用。本项目以当前可较大规模制备、多缺陷结构的氧化石墨烯为原料，对其面内和边缘缺陷结构进行全面调控，获取高性能非掺杂石墨烯基无金属催化剂，揭示催化剂微观结构与催化加氢性能之间的关联机制，深入催化加氢作用研究，并设计高效催化反应。采用绿色化学联合温控超声法逐步分别调控石墨烯片层面内官能团和边缘缺陷结构。利用X射线光电子能谱、衰减全反射傅里叶红外光谱等跟踪确定石墨烯基催化剂面内特征官能团及其相对含量，借助拉曼光谱分析边缘缺陷结构，基于紫外可见光谱原位检测来实时跟踪催化加氢反应，并结合催化剂结构调控与催化反应条件正交优化，实现非掺杂石墨烯基无金属高效催化加氢反应设计，为可控合成高性能碳基无金属催化剂及设计高效催化反应提供新的思路和方向,并形成原创性成果。

非掺杂石墨烯碳基无金属催化加氢（还原）材料是目前重要的研究方向，因其具有替代贵金属基催化剂良好的应用前景，涉及到催化氧还原、催化有机底物还原、催化二氧化碳还原等重要转化反应，但是受限于石墨烯惰性的本征结构和表面性质，目前对于开发具有高活性的石墨烯碳基无金属材料仍然是一个极具挑战性的研究课题。本项目首先以当前可较大规模制备、多缺陷结构的氧化石墨烯（GO）为原料，采用绿色化学联合温控超声法，系统地调控了GO片层面内官能团和边缘缺陷结构，获得了具有突出边缘缺陷结构效应的还原氧化石墨烯量子点（rGOQDs），阐明了从二维（2D）的GO到零维（0D）的rGOQDs结构的转化机制，实现了对有机底物的高效率地富集（对亚甲基蓝有机底物的最大富集量高达827.5 mg g-1），解析了rGOQDs与有机底物之间的相互作用机制，有利于获取高效的石墨烯碳基无金属催化有机底物还原反应；通过对GO进行微结构调控、表面改性和功能化处理，得到了一系列高性能的石墨烯碳基吸附剂和催化剂，实现了可方便快捷地富集有机底物以及催化有机底物加氢，研究了反应动力学和热力学过程，探讨了石墨烯碳基材料与有机底物之间的富集和催化作用机制，并提出了新的催化加氢反应机理；还通过转化生物质废弃物，制备得到了具有低成本和高比表面积的碳基无金属催化材料，实现了可媲美甚至优于典型的铂/碳（Pt/C）贵金属基催化剂的催化氧还原反应活性和持久耐用性，并阐明了其中的碳基无金属催化氧还原反应途径，从而为替代贵金属基催化剂提供了具有低成本和高性能的碳基无金属催化剂，将在涉及催化加氢（还原）反应的工业领域具有重要的应用前景。本项目的研究成果还将为可控合成高性能碳基无金属催化剂以及设计高效催化反应提供新的思路和方向。