The aromatic nature of coal results in highly graphitized hard carbon (HC), which significantly impacts its sodium storage performance. Constructing oxygen‐containing functional groups (OFGs) can effectively enhance sodium storage performance, but the mechanistic role of OFGs in governing the surface chemical evolution of coal‐based HC remains poorly understood. Herein, OFGs are introduced into coal molecules through various pre‐oxidation methods. Comprehensive in situ/ex situ testing elucidated that different OFGs have different effects on the intramolecular rearrangement of coal. Compared with C═O, ‐OH, and C─O─C groups, the carboxyl can inhibit decarboxylation during pyrolysis, raising the upper limit of the temperature window for intramolecular carbon rearrangement from 500 to 600 °C. This effect reduces intermolecular condensation efficiency during carbonization, thereby suppressing soft carbon formation. The strategy concurrently enlarges graphite‐like interlayer spacing and creates closed pores, ultimately enhancing the sodium storage capacity of coal‐based HC. The optimized HC shows enhanced capacity (308 mAh g ⁻¹ ) with a 1.4 times increase in low‐voltage plateau capacity compared to the unmodified HC. This work elucidates the structure‐function relationship between specific OFGs and carbonization behavior, develops a practical strategy to modulate coal's molecular rearrangement via targeted surface chemistry, and contributes to achieving low‐cost, high‐performance HC in advanced SIBs.

The use of coal as a precursor for producing hard carbon is favored due to its abundance, low cost, and high carbon yield. To further optimize the sodium storage performance of hard carbon, the introduction of heteroatoms has been shown to be an effective approach. However, the inert structure in coal limits the development of heteroatom-doped coal-based hard carbon. Herein, coal-based P-doped hard carbon was synthesized using Ca₃(PO₄)₂ to achieve homogeneous phosphorus doping and inhibit carbon microcrystal development during high-temperature carbonization. This involved a carbon dissolution reaction where Ca₃(PO₄)₂ reacted with SiO₂ and carbon in coal to form phosphorus and CO. The resulting hierarchical porous structure allowed for rapid diffusion of Na⁺ and resulted in a high reversible capacity of 200 mAh g⁻¹ when used as an anode material for Na⁺ storage. Compared to unpretreated coal-based hard carbon, the P-doped hard carbon displayed a larger initial coulombic efficiency (64%) and proportion of plateau capacity (47%), whereas the unpretreated carbon only exhibited an initial coulombic efficiency of 43.1% and a proportion of plateau capacity of 29.8%. This work provides a green, scalable approach for effective microcrystalline regulation of hard carbon from low-cost and highly aromatic precursors.

This paper presents the results of a study of the catalytic hydrogenation of phenanthrene using catalysts based on chrysotile modified with nickel and titanium (chrysotile/NiTi), as well as coal shale. Complex characterization of catalysts in terms of acid, texture and morphological properties was carried out. Pre-reduction in the catalysts has been found to increase the yield of partially and fully hydrogenated products, including tetrahydronaphthalene, trans-decalin and dihydrophenanthrene. Particular attention is paid to the role of coal shale as a donor source of hydrogen in thermolysis conditions. The results of hydrogenation revealed complex mechanisms of phenanthrene transformations, including partial saturation of aromatic rings, desulfurization and the formation of alkyl-substituted compounds. The obtained data emphasize the prospects of using the studied catalysts in the processes of processing heavy and solid hydrocarbon raw materials, which opens up opportunities for creating new technologies for the production of liquid fuel.

The conversion of lignite into aromatic compounds by highly active catalysts is a key strategy for lignite valorization. In this study, Ni/NiO@NC nanocomposites with a high specific surface area and a vesicular structure were successfully prepared via a facile sol–gel method. The Ni/NiO@NC catalysts exhibited excellent catalytic activity for the catalytic hydroconversion (CHC) of benzyloxybenzene (as lignite-related modeling compounds) under mild conditions (120 °C, 1.5 MPa H₂, 60 min). The possible mechanism of the catalytic reaction was investigated by analyzing the type and content of CHC reaction products at different temperatures, pressures, and times. More importantly, the magnetic catalyst could be conveniently separated by a magnet after the reaction, and it maintained high catalytic efficiency after six reuses. This study provides an efficient and recyclable catalyst for the cleavage of >CH–O bonds in lignite, thereby offering another way for improved utilization of lignite.

Ethanolysis is an effective method to depolymerize weak bonds in lignite under mild conditions, which can result in the production of high-value-added chemicals. However, improving ethanolysis yield and regulating its resulting product distribution is a big challenge. Hence, exploiting highly active catalysts is vital. In this work, Fe₂(MoO₄)₃ catalysts with zero-dimensional nanoparticles, one-dimensional (1D) nanorods, two-dimensional (2D) nanosheets, and three-dimensional (3D) nanoflower structures were successfully prepared and applied in the ethanolysis of Naomaohu coal. The results showed that for all samples, the yield of ethanol-soluble portions (ESP) was significantly improved. The highest yield was obtained for the Fe₂(MoO₄)₃ nanorods, with an increase from 28.84% to 47.68%, and could be attributed to the fact that the Fe₂(MoO₄)₃ nanorods had a higher number of exposed active (100) facets. In addition, the amounts of oxygen-containing compounds, such as ethers, esters, and phenols, increased significantly. The mechanism of ethanolysis catalyzed by the Fe₂(MoO₄)₃ nanorods was also studied using phenylbenzyl ether (BOB) as a model compound. BOB was completely converted at 260 °C after 2 h. It is suggested that Fe₂(MoO₄)₃ nanorods can effectively break the C-O bonds of coal macromolecules, thus promoting the conversion of coal.

NaFePO4 (NFP) is a promising alternative to LiFePO4, offering advantages such as the abundance of natural sodium resources. However, its common crystal phase, maricite, is typically electrochemically inert. This study presents a novel, synthesis-controllable, and rechargeable maricite NFP cathode material, specifically Na0.33Fe0.95Ca0.06PO4, for sodium-ion batteries. The structure provides two main benefits: Ca2+ doping broadens the bulk sodium-ion transport channels, while the dynamic and persistent Jahn-Teller distortion caused by the coexistence of Fe4+, Fe3+, and Fe2+ induces internal lattice distortion, effectively activating its electrochemical activity. Additionally, nanocrystallization introduces external structural disorder, further shortening the ion diffusion path. This cathode exhibits a high reversible capacity of 178.6 mAh g-1 at 50 mA g-1 and a material-based energy density of 415 Wh kg-1. This study offers a general strategy for activating electrochemically inert yet potentially viable battery materials, providing new insights for developing next-generation, high-performance, and low-cost energy storage systems.