NiW/USY-γ-Al_{2O3 modified by P, Zr and Mn for hydrogenation of coal tar to clean fuel}

NiW/USY-γ-Al2O3 catalysts modified by P, Zr and Mn were prepared by incipient wetness co-impregnation method. The addition of P significantly elevated the acid strength and the content of medium-strong acids, while the addition of Zr decreased the content of the medium-strong acids. The addition of Mn almost did not change the acidity of the catalyst. All catalysts were evaluated by using the diesel fraction from the hydrotreated coal tar and the naphthalene as feedstock. P, Mn and Zr modification all improved the overall hydrocracking activity of catalysts. The catalytic activity of P-NiW/USY-γ-Al2O3 and Mn-NiW/USY-γ-Al2O3 for hydrocracking of polycyclic aromatic hydrocarbons was higher than that of NiW/USY-γ-Al2O3 and Zr-NiW/USY-γ-Al2O3. Disparate hydrogenation or cracking activity of modified catalysts was observed. [Received: August 4, 2020; Accepted: January 6, 2021]