在我国，以储量丰富的煤炭为原料制备用于超级电容器的电容炭，是实现煤炭资源清洁、高附加值利用的有效途径。尤其是太西煤这一珍惜煤种，更应作为制备电容炭的原料，充分发挥其资源价值。然而，煤中复杂的有机质和矿物组分导致煤基电容炭的制备过程仍面临诸多问题。一方面，由于缺乏对煤制备电容炭过程中结构演变机制的认识，难以实现对电容炭微观结构的精准调控。另一方面，传统制备过程中使用的危险化学品，会产生严重的环境污染，限制了煤基电容炭的规模化生产。鉴于上述问题，明晰煤基电容炭制备过程中的结构演变机制，并实现对其微观结构的精准调控，是制备高性能煤基电容炭的关键。同时，摒弃传统高污染、高危害的化学品，设计绿色制备工艺，将有助于煤炭资源的清洁高效利用。

本文从原料处理、炭化脱挥发分、活化造孔和除杂纯化的整条电容炭制备工艺链出发，以太西煤（TX6）为原料，设计了物理-化学分步活化和有机酸纯化工艺制备高性能的超纯电容炭；从分子层面出发，构建了TX6分子模型以指导炭化活化过程；研究了炭化活化反应特性和机理；探讨了活化条件对电容炭微观结构的影响；探究了电容炭微观结构和电化学性能之间的关系；提出了小分子有机酸脱出电容炭灰分的新思路。主要研究内容和结论如下：

（1）采用元素分析、¹³C核磁共振、傅里叶变化红外光谱和X射线光电子能谱对TX6煤样的结构和组成进行表征分析，构建了分子式为C₂₂₂H₁₁₉NO₁₁的大分子平面模型。由模型可知，TX6具有高度集中的四苯稠环芳烃结构。进一步采用分子力学和分子动力学对平面模型进行优化，获得了三维模型。模型中的平行芳香片层为TX6在储能领域提供了结构基础。通过化学键键长计算，表明TX6具有稳定的芳香碳和活泼的脂肪族碳，可知炭化活性位点主要集中在脂肪族结构。

（2）以TX6三维模型为基础，采用炭化实验联合反应分子动力学（ReaxFF MD）和密度泛函理论（DFT）研究炭化过程和反应机理。炭化实验表明炭化反应符合一级动力学特征，气体产物释放规律符合二次方程。ReaxFF MD计算显示升高温度和延长时间可实现TX6分子的交联，其中温度影响更为显著。反应速率常数和温度的关系遵循Arrhenius方程，由此计算了炭化反应所需的活化能。DFT计算研究了炭化反应过程中生成的典型自由基及中间产物。计算表明TX6炭化反应大致包括桥键、侧链、含氧官能团结构的断裂，析出气体产物。TX6大分子自由基分子内和分子间的反应促使炭化料形成。炭化料分子显示了致密芳构化特征，活化过程主要刻蚀芳香环碳。

（3）借助中心复合设计优化水蒸气活化工艺参数，制备了一次活化电容炭（CAC_Ⅰ-O）。构建了活化条件影响比电容的数学模型，并据此确定了最佳活化条件。优化活化条件实现了炭化料结构从致密向多微孔的转变（比表面积为1545 m²/g，孔容为0.78 cm³/g）。同时，活性位点增多（I_D/I_G为0.95~1.04），表面氧化学结构以酚类和酯类为主。制备的CAC_Ⅰ-O在0.5 A/g时的比电容为194.35 F/g。DFT计算揭示了水蒸气刻蚀芳香环碳并移除碳原子的路径和机理，表明该过程中会释放H₂和CO，同时产生苯酚官能团。

（4）通过Box-Behnken设计，优化了KOH浸渍CAC_Ⅰ-O二次活化工艺，制备了二次活化电容炭（CAC_Ⅱ-O）。构建了浸渍条件影响比电容的数学模型，并确定了最佳浸渍条件。浸渍法可使碱煤比低于0.6:1。最优的浸渍条件可实现孔结构的进一步发育形成分级孔结构（比表面积为1909.92 m²/g，孔容为1.23 cm³/g），活性位点进一步增多（I_D/I_G为1.00~1.20）。制备的CAC_Ⅱ-O在0.5A/g时的比电容为334.2 F/g。组装的CAC_Ⅱ-O//CAC_Ⅱ-O对称器件在功率密度为500 W/kg时的能量密度为31.15 Wh/kg。

（5）采用七种有机酸作为浸出剂对CAC_Ⅱ-O进行纯化，发现单组分酸均具有明显的脱灰效果，但存在一定的差异性，其主要与配体分子的性质有关。一元羧酸可络合钙形成可溶性钙盐，对含钙矿物具有较强的去除能力。二元羧酸和柠檬酸可螯合铝和硅，对硅铝酸盐矿物具有较强的去除能力。根据CAC_Ⅱ-O中矿物特点，选用甲酸、草酸和柠檬酸组成的混合酸作为浸出剂纯化CAC_Ⅱ-O。三种酸的协同作用使得脱灰效果更明显（灰分为0.48%）。制备的超纯电容炭（CAC_Ⅲ）未出现明显微观结构破坏，且具有更优异的电化学性能。其中，串联阻抗可降低0.764 Ω，组装的CAC_Ⅲ//CAC_Ⅲ对称器件在10000个工作循环后的电容保持率高达91.69%。展现了比商业电容炭YP-50F更优异的电容性能。

In China, using coal, which has abundant reserves, as raw materials to prepare capacitive carbon for supercapacitors is an effective way to achieve the clean and high value-added utilization of coal resources. In particular, Taixi coal, a rare coal species, should be used as the raw material for preparing capacitive carbon to full utilize its resource value. However, due to the complex organic matter and mineral components in coal, the preparation process of coal based capacitive carbon still faces many problems. On the one hand, due to the lack of understanding of the structural evolution mechanism in the process of preparing capacitive carbon from coal, it is difficult to achieve accurate regulation of the microstructure of capacitive carbon. On the other hand, the hazardous chemicals used in the traditional preparation process can cause serious environmental pollution, which restricts the large-scale production of coal-based capacitive carbon. Based on the over problems, clarifying the structural evolution mechanism in the preparation process of coal based capacitive carbon and achieving the precise control of its microstructure are the keys to preparing high performance coal based capacitive carbon. At the same time, abandoning the traditional high pollution and high hazard chemicals and designing a green preparation process will contribute to the clean and efficient utilization of coal resources.

In this paper, we started from the entire preparation process chain of capacitive carbon, including raw material treatment, carbonization to remove volatiles, activation to format pores and purification to remove impurities. Taixi coal (TX6) was used as raw material. The process of high performance ultra-pure capacitive carbon though step by step physical-chemical activation and purification with organic acid was designed. From the molecular level, TX6 molecular model was constructed to guide the carbonization and activation process. The reaction characteristics and mechanism of carbonization and activation were studied. The influence of activation conditions on the microstructure of capacitive carbon was explored. The relationship between the microstructure and electrochemical properties of capacitive carbon was investigated. A new idea of removing the ash form capacitive carbon with small molecular organic acids was proposed. The main research contents and conclusions as follows:

(1) Elements analysis, ¹³C nuclear magnetic resonance, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize the structure and composition of TX6 coal samples. A large molecular plane model with the molecular formula C₂₂₂H₁₁₉NO₁₁ was constructed. It could be known from the model that TX6 had a highly concentrated tetraphene polycyclic aromatic hydrocarbon structure. Furthermore, the planar model was optimized by molecular mechanics and molecular dynamics, and the three-dimensional model was obtained. The parallel aromatic layer in the model provided the structural basis for TX6 in the field of energy storage. The calculation of chemical bond length showed that TX6 has stable aromatic carbon and active aliphatic carbon. It could be known that the active sites for carbonization were mainly concentrated in the aliphatic structures.

(2) Based on the three-dimensional model of TX6, carbonization experiments combined with reaction molecular dynamics (ReaxFF MD) and density functional theory (DFT) were used to study the carbonization process and reaction mechanism. The carbonization experiment showed that the carbonization reaction conformed to the characteristics of first-order kinetic, and the release law of the gas product conformed to a quadratic equation. ReaxFF MD calculation showed that TX6 molecules could be cross-linked by increasing temperature and extending time, among which the influence of temperature was more significant. The relationship between the reaction rate constant and temperature followed the Arrhenius equation, and the activation energy required for the carbonization reaction was calculated accordingly. DFT calculations studied the typical free radicals and intermediate products generated during the carbonization reaction process. The calculations indicated that the carbonization reaction of TX6 roughly included the fracture of bridge bond, side chain and oxygen-containing functional group structure leading to the evolution of gas products, and the intramolecular and intermolecular reactions of TX6 macromolecular free radicals contributed the formation of carbonized materials. The molecules of the carbonized material showed the characteristics of dense aromatization, and the activation process mainly etched carbon in the aromatic rings.

(3) Primary activated capacitive carbon (CAC_I-O) was prepared by optimizing the process parameters of water steam activation with the help of central composite design. A mathematical model of the influence of activation conditions on specific capacitance was constructed, and the optimal activation conditions were determined accordingly. The optimal activation conditions achieved the transformation of the structure of carbonized material from a dense state to a state with numerous microporous (specific surface area of 1545 m²/g, pore volume of 0.78 cm³/g). At the same time, the number of active sites increased (I_D/I_G ranged from 0.95 to 1.04), and the surface oxygen chemical structure were mainly composed of phenolic and ester groups. The specific capacitance of the prepared CAC_I-O was 194.35 F/g at 0.5 A/g. DFT calculations revealed the path and mechanism by which water vapor etched the carbon in the aromatic ring and removed carbon atoms, indicating that H₂ and CO were released during this process, and the phenolic functional groups were generated simultaneously.

(4) Through Box-Behnken design, the secondary activation process of CAC_I-O impregnated with KOH was optimized, and secondary activated capacitor carbon (CAC_II-O) was prepared. A mathematical model of the influence of impregnation conditions on specific capacitance was established, and the optimum impregnation conditions were determined. The impregnation method could make the ratio of alkali to coal lower than 0.6:1. The optimum impregnation conditions could achieve the further development of the pore structure and form a hierarchical pore structure (specific surface area of 1909.92 m²/g, pore volume of 1.23 cm³/g). The number of active sites was further increased (I_D/I_G ranged from 1.00 to 1.20). The specific capacitance of the prepared CAC_II-O was 334.2 F/g at 0.5A/g. The assembled CAC_II-O//CAC_II-O symmetrical device had an energy density of 31.15 Wh/kg when the power density was 500 W/kg.

(5) Seven kinds of organic acids were used as leaching agents to purify CAC_II-O. It was found that each single component acids had an obvious deashing effect, but there were certain differences, which were mainly related to the properties of the ligand molecules. Monocarboxylic acid could complex with calcium to form soluble calcium salts, and had a strong ability to remove calcium-containing minerals. Dicarboxylic acid and citric acid could chelate aluminum and silicon, and had a strong to remove aluminosilicate minerals. According to the characteristics of the mineral in the CAC_II-O, a mixed acid composed of formic acid, oxalic acid and citric acid was selected as leaching agent to purify CAC_II-O. The synergistic effect of the three acids maked the deashing effect more obvious (ash content is 0.48%). The prepared ultra-pure capacitive carbon (CAC_III) did not show obvious damage to its microstructure, and it had better electrochemical properties. Among them, the series impedance could be reduced by 0.764 Ω. After 10,000 working cycles, the capacitance retention rate of the assembled CAC_III//CAC_III symmetric device was as high as 91.69%. It showed more excellent capacitive performance than the commercial capacitive carbon YP-50F.