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N-doped hierarchical mesoporous carbons have been fabricated by using mesophase pitch (MP) as a carbon precursor and polypyrrole as a nitrogen resource through the MCM-48 template. Carbonization temperature plays a key role in the morphology, mesoporous structure, and electrochemical properties of N-doped porous carbons (NPCs). At an appropriate carbonization temperature (700 °C), as-prepared NPC-700 exhibits rich nitrogen content (4.48 wt %), medium specific surface area (495.9 m 2 g −1 ), and high specific capacitance of 232.2 F g −1 at a current density of 2 A g −1 in a three-electrode system. Due to the generation of pseudocapacitance, the specific capacitance of NPC-700 is 53.6 F g −1 higher than that of PC-700 without polypyrrole. In addition, NPC-700 shows high specific capacitance of 110.6 F g −1 at a current density of 0.2 A g −1 , a good capacitance retention of 77.8% at the current density of 5 A g −1 , and the large energy density of 15.30 Wh kg −1 at a power density of 399.9 W kg −1 in a two-electrode system. This work provides a novel example of how N-doped porous carbons derived from mesophase pitch and polypyrrole can be used as a promising electrode material for potential energy storage applications.

High-resolution matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) combined with other analytical techniques and aromatic structure analysis were employed to characterize and identify large polycyclic aromatic hydrocarbons (PAHs) in coal tar pitch and its hexane-soluble fraction. Nonsubstituted aromatics in high abundance up to 850 Da can be extracted successfully with defined molecular formula from MALDI spectra, and mapped systematically into a 50/24 matrix, indicating a structural growth pattern by cooperative ortho-condensation and bay-condensation. The matrix provided a quantitative summary, with their quantity and chemical structures defined essentially by MS intensity and molecular formula of PAHs isomers, respectively. It also revealed a trend that the PAHs grown alternatingly at ortho and bay positions exhibit much higher concentrations than those by ortho- or bay-condensations alone, even though their relative abundance by MS intensity may drop as aromatic rings grow with condensation polymerizations. Such compositional insights may be valuable for better utilization of coal tar pitch as well as understanding the overall reactions that lead to the formation of such a complex mixture including very small and very large polycyclic aromatic compounds.

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