多环芳烃(polycyclic aromatic hydrocarbons，PAHs)是煤焦油中最主要的成分之一，通过加氢饱和可制取具有高能量密度和高热稳定性的喷气燃料。通过分析PAHs加氢过程特点，指出PAHs自身的共振能和加氢中间产物的空间位阻，以及原料和中间产物在催化剂活性位上的竞争吸附是PAHs加氢饱和的关键难题。

综述了近年来PAHs加氢饱和催化剂的研究进展，分析了影响催化剂性能的本质原因，指出提高催化剂活性金属组分的分散度、减小催化剂金属颗粒尺寸可以使催化剂具有更多的加氢活性位点，活性金属适宜的缺电子状态能促进PAHs分子在活性位点上的吸附活化，抑制竞争吸附带来的不利影响。具有丰富孔道和介孔(6~8 nm)结构的催化剂载体有利于PAHs和加氢中间产物的扩散，降低加氢中间产物的空间位阻对加氢反应的不利影响，同时可提供更多的反应表面，促进深度加氢反应进行。酸性适宜的载体可以与活性组分产生相互作用，促进活性组分形成适宜的缺电子状态。总结了PAHs加氢饱和过程的热力学和动力学特征，PAHs加氢反应为放热可逆反应，平衡常数和平衡转化率随反应温度降低而增大，随反应压力的升高而增大，PAHs的扩散性随反应温度的升高而增强，吸附常数随饱和环数的增加而减小。

最后，从催化剂活性组分和载体的设计及调控、PAHs加氢饱和过程热力学和动力学研究等方面提出了研究建议。对煤焦油中PAHs加氢饱和过程及其催化剂的分析和讨论将为富油煤资源高效开发利用提供有益指导。

Polycyclic aromatic hydrocarbons (PAHs), a predominant component in coal tar, can be used to produce jet fuels with high energy density and thermal stability through hydrogenation saturation. Based on the characteristics of the PAH hydrogenation process, this study proposed that primary challenges in PAH hydrogenation saturation include the resonance energy of PAHs themselves, the spatial site resistance of hydrogenation intermediates, and the competitive adsorption of feedstocks and intermediates on active sites in the catalysts.

Based on the review of research progress in catalysts for PAH hydrogenation saturation in recent years, this study analyzed the substantial factor influencing the catalyst performance, and key findings are as follows: (1) More hydrogenation active sites in catalysts can be obtained by increasing the dispersion of the active metal components in catalysts and reducing the sizes of metal particles in catalysts, with appropriate electron-deficient states of active metals in catalysts promoting the adsorption and activation of PAH molecules on the active sites and inhibiting the adverse effects caused by the competitive adsorption. (2) Catalyst carriers with abundant pore throats and mesopore structures (6‒8 nm) are favorable for the diffusion of PAHs and hydrogenation intermediates, thus reducing the adverse effects of hydrogenation intermediates' spatial site resistance on hydrogenation reactions. Meanwhile, these catalyst carriers can provide more reaction surfaces, thereby enhancing deep hydrogenation reactions. (3) The interactions between acidic suitable carriers and active components can promote the formation of suitable electron-deficient states of the active components. A summary of the thermodynamic and kinetic characteristics of the PAH hydrogenation saturation process revealed that the PAH hydrogenation reactions are exothermic and reversible, with the equilibrium constant and equilibrium conversion increasing with decreasing reaction temperature and increasing reaction pressure, the PAH diffusion intensifying with an increase in the reaction temperature, and the adsorption constant decreasing with an increase in the number of saturated rings.

This study proposed suggestions for research on the design and adjustment of the active components and carriers of catalysts, along with the thermodynamics and kinetics of the PAH hydrogenation saturation process. The analyses and discussions of the hydrogenation saturation process of PAHs in coal tar and catalysts in this study will provide useful guidance for the efficient exploitation and utilization of tar-rich coal resources.