Developing cost-effective and highly active catalysts for the hydrogenation of polycyclic aromatic hydrocarbons (PAHs) to produce high-density fuel components is of significant importance and poses a considerable challenge for the utilization of heavy carbon resources such as coal tar. In this work, a series of nickel phosphide catalysts (xNiP/DMSN) were prepared using dendritic mesoporous silica (DMSN) as the support and phytic acid (PA) as both the phosphorus source and chelating agent. These catalysts exhibited excellent catalytic performance in the hydrogenation of PAHs. Specifically, the optimal catalyst 2NiP(PA)/DMSN achieved 99% conversion of phenanthrene and 99% selectivity towards perhydrophenanthrene at 260 ^oC and 3 MPa H₂ pressure. Under the same conditions, pyrene also achieved a 99% conversion and over 70% selectivity for perhydropyrene. The catalytic performance was significantly improved compared to that of 2NiP/DMSN prepared using (NH₄)₂HPO₄ as the phosphorus source. Meanwhile, the hydrogen consumption was significantly reduced; even when the H2/oil ratio was decreased from 800:1 to 200:1, no obvious changes were observed in the conversion rates of phenanthrene and pyrene, nor in the selectivity of the perhydrogenated products. Detailed characterization analyses revealed that PA plays a crucial role in the uniform dispersion of Ni species and the formation of active nickel phosphide nanoparticles. Within the active nanoparticles, electron transfer from Ni to P generates Ni^δ+ species, which promotes the adsorption and activation of PAHs and enhances deep hydrogenation saturation. Furthermore, the catalyst also exhibited high catalytic performance for the hydrogenation of mixed PAHs. This work provides a convenient strategy and theoretical basis for the design of catalysts for PAHs hydrogenation to produce high-density fuel components.
 

PAHs,hydrogenation saturation,cycloalkanes,nickel phosphide,electronic modulation