Precious Metals Catalyze the Saturated Hydrogenation of Polycyclic Aromatic Hydrocarbons in Coal Tar

As a significant by-product of coal pyrolysis processes, coal tar is rich in polycyclic aromatic hydrocarbons (PAHs), garnering considerable attention for their potential conversion into high-value products through saturation hydrogenation. This paper presents a comprehensive review of recent advancements in two key areas: progress in high-activity saturated hydrogenation of PAHs catalyzed by precious metals and the regulation of cis–trans isomeric configuration of their hydrogenation products. Furthermore, the investigation addresses two critical challenges involved in the field: the susceptibility of precious metal catalysts to sulfur poisoning during the coal tar’s hydrogenation and the difficulty in controlling the stereo-isomerization of hydrogenation products. This review will advance fundamental understanding of PAHs hydrogenation mechanisms and provide critical technical guidance in coal tar utilization, supporting the sustainable development of clean energy technologies and high-value chemical production from coal by-products.