Sulfur-tolerant Pd–Pt/Al2O3–B2O3 catalyst for aromatic hydrogenation

Hydrogenation of tetralin was done over a bimetallic Pd–Pt catalyst supported on amorphous Al2O3–B2O3 at a hydrogen pressure of 3.9 MPa at 553 K in the presence of dibenzothiophene (sulfur content of 500 ppm by weight). The resulting activity and selectivity were compared with those for Pd–Pt supported on amorphous SiO2–Al2O3, γ-Al2O3, SiO2, and USY zeolites. Pd–Pt/Al2O3–B2O3 had high sulfur tolerance; it showed higher activity than Pd–Pt/SiO2–Al2O3, Pd–Pt/γ-Al2O3, Pd–Pt/SiO2, or Pd–Pt/USY (SiO2/Al2O3 = 680), but slightly lower activity than Pd–Pt/USY (SiO2/Al2O3 = 40). Furthermore, Pd–Pt/Al2O3–B2O3 showed excellent hydrogenation selectivity. This catalytic system, therefore, is promising for practically reducing the aromatics in diesel fuels.