煤中石墨烯结构的赋存分布与热演化规律及其影响因素研究

Differing from graphite, petroleum coke, etc., the formation of coal-based graphene is controlled by many factors. However, the current preparation of graphene and its family derivatives using coal as a carbon source is still in its infancy, and the research focused on the influence of coal petrology and coal quality on the products is deficient. Therefore, from the point of the origin of coal petrology and coal quality, based on the mature preparation process of coal-based graphene and its derivatives, using modern test technologies and methods such as transmission microscopy, atomic force microscopy, X-ray technology, nuclear magnetic resonance, and quantum chemistry, the occurrence and distribution of graphene in coals with different macerals and metamorphic types as well as the morphology, structure, and properties of coal-based graphene will be systematically studied; the optimal combination conditions and reaction characteristics of the preparation of coal-based graphene under different temperatures, heating rates, pressures, atmospheres, and additives will be studied in detailed; the effects of geological and artificial conditions on the structure and properties of coal-based graphene will be discussed; the formation mechanism of coal-based graphene will be analyzed and the distribution, origin, and thermal changes of the graphene structure in coal will be revealed. The research results can not only enrich the theory of the formation and thermal evolution of coal, but also provide scientific basis for the high value-added utilization of coal, expanding the sources of materials of graphene preparation.

不同于石墨、石油焦等，煤基石墨烯形成的受控因素较多，但是目前以煤为碳源制备石墨烯及其家族衍生物的研究尚属于起步阶段，缺乏从煤岩煤质角度对产品影响的研究。因此，本申请项目从煤岩煤质成因角度考虑，以成熟的煤基石墨烯及其衍生物制备工艺为依托，采用透射显微镜、原子力显微镜、X射线技术、核磁共振以及量子化学技术等现代测试技术与方法，系统研究不同显微组分和变质类型的煤中石墨烯结构的组成、成因以及其制备石墨烯的形貌、结构、属性；深入分析不同温度、升温率、压力、氛围和添加剂等条件下制备煤基石墨烯的最佳组合条件和反应特性；探讨地质因素和人工条件对煤基石墨烯结构及属性的影响；分析煤基石墨烯形成机理，揭示煤中石墨烯结构的赋存分布、成因及热变化规律。研究成果既可丰富成煤作用及煤热演化理论，又可为煤的高附加值利用、扩展石墨烯制备材料来源等提供科学依据。

煤基石墨烯及其衍生材料的研究与开发应用，是一项值得深入探索而又有助于实现煤炭的高效洁净无害化利用的重要途经。本项目以中国山西省、宁夏回族自治、贵州省、福建省、云南小发路和京西等地高煤阶煤为研究对象，采用石墨烯量子点提取和煤石墨化氧化还原法提取石墨烯等两种工艺为载体，利用多学科理论，运用光学显微镜、SEM-EDS、HRTEM、XRD、FTIR、XPS、Raman和13C-NMR等现代先进测试手段及ACD/CNMＲpredictor等多种分析方法, 从煤岩学、煤化学、煤地球化学和煤工艺学等多学科角度开展了煤中石墨烯结构的赋存与分布、煤制石墨烯过程中石墨烯结构的热演化规律和煤基石墨烯形成的影响因素等三方面的研究。结果表明，煤石墨烯结构及热演化受煤显微组分、煤阶、煤变质类型、煤成因类型、氢含量、有机硫、矿物质以及石墨化温度等因素的影响；煤显微组分与石墨烯GS和石墨烯量子点GQDs 的制备产率存在相似关系：高煤级镜质体＞惰质体＞中煤级镜质体＞树皮体、角质体，其粒径平均大小关系有：角质体＜树皮体＜镜质体 ＜惰质体；同时GS和GQDs 的尺寸随着煤级升高而明显增加，其晶体缺陷降低，有序度增加，其层片更平直化；煤基石墨烯产品有岩浆热变质煤好于接触变质煤，后者有好于深成变质煤；荧光量子产率随着原煤变质程度增加而先升高后降低；煤中有机硫不利于煤基石墨烯的制备但超高有机硫低挥发分烟煤制备的 GQDs荧光量子产率较高；小发路煤中检测出5种羟基，其自由氢含量越高，制备煤基石墨化越有利，形成的煤基石墨越容易氧化和插层；煤中矿物质不利于煤基石墨烯的制备，脱灰有利于提高煤基GS和GQDs产率。运用HRTEM和XRD构建了一种测定煤芳香核结构参数的方法，应用13C-NMR预测软件ACD/CNMR Predictor进行了修正，获得了京西无烟煤的几何结构优化的分子结构模型。项目丰富了煤中石墨烯及其碳量子的形成与分布理论，为煤基石墨烯及其量子点产品的制备与利用提供了科学依据。