The constituents of coal tar pitch (CTP) significantly impact the wettability of calcined coke (CC) and the performance of prebaked anodes (PA) used in aluminum electrolysis. However, balancing wettability and carbon residue within CTP remains a central challenge in material applications. In addition, limited pore permeability and structural stability in these composites hinder the effective utilization of PA. Enhancing CTP fluidity is crucial for overcoming these challenges. In this work, a novel method was developed to modify CTP utilizing various coal tar fractions, enabling controlled modulation of CTP composition and wettability. Incorporating different fractions allowed for substantial control over interfacial bonding and pore structure. The chemical composition, functional groups, and elemental content of the CTP were analyzed via X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and proton nuclear magnetic resonance (1H NMR). Subsequently, systematic comparisons of PA materials produced from different CTP formulations demonstrated improved wettability and enhanced mechanical properties. Moreover, DFT calculations were performed to compare the adsorption energies of small molecules from different coal tar fractions with coke, reflecting the interaction strength between the molecules and the solid surface. Using micro-computed tomography (μ-CT), the refined pore structure was examined, resulting in a PA composite with an optimized balance of high strength and toughness.

Chemical composition-driven wettability and pore structure modulation in coal tar pitch for enhanced prebaked anode performance in aluminum electrolysis
    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Materials
        2.2 Preparation procedure
            2.2.1 Preparation of modified CTP
            2.2.2 Preparation of PA
        2.3 Analysis methods
    3 Results and discussion
        3.1 Characteristics of the modified pitches
        3.2 Wetting characteristics of PA by different CTP at different time
        3.3 XPS analysis
        3.4 FT-IR and 1H NMR analyses
        3.5 Surface structure analysis
        3.6 Interaction between distillates and PI
        3.7 PA properties
        3.8 Quantitative 3D pore networks
        3.9 Mechanism of wettability of pitch to coke on properties of PA
    4 Conclusion
    Acknowledgements 
    References

• Jun Ma(College of Materials Science and Engineering, Hunan University, Changsha 410082, China)
• Shen Zhu(College of Materials Science and Engineering, Hunan University, Changsha 410082, China)
• Xueli Wu(College of Materials Science and Engineering, Hunan University, Changsha 410082, China)
• Xun He(College of Materials Science and Engineering, Hunan University, Changsha 410082, China)
• Yanli Liu(College of Materials Science and Engineering, Hunan University, Changsha 410082, China)
• Chuanjun Tu(College of Materials Science and Engineering, Hunan University, Changsha 410082, China) Corresponding author
• Weiyi Wang(Ankang Tailun New Materials Co., Ltd, Ankang 725103, China, Ankang Carbon Graphite Special Materials Engineering Technology Research Center, Ankang 725103, China)
• Juan Li(Sunstone Development Co., Ltd, Dezhou 251500, China)
• Cheng Yang(Hunan Changyu Technology Development Co., Ltd, Changsha 410000, China)