Catalytic Performance of the New Delaminated ITQ-2 Zeolite for Mild Hydrocracking and Aromatic Hydrogenation Processes

Catalysts based on NiMo and Pt supported on the new delaminated ITQ-2 zeolite have been prepared and their catalytic properties evaluated for the mild hydrocracking (MHC) of vacuum gasoil and aromatic hydrogenation. The results were compared with those obtained using other conventional supports, e.g., silica, γ-alumina, amorphous silica–alumina (25 wt% Al2O3), and USY zeolite, all of which contain the same metal loading as the ITQ-2 material. In the case of MHC of vacuum gasoil, NiMo/ITQ-2 displayed a higher hydrocracking activity than NiMo/SiO2–Al2O3 and NiMoγ-Al2O3, and even higher activity than NiMo/USY in the range 375–425°C. Moreover, NiMo/ITQ-2 had a selectivity to middle distillates intermediate between those of NiMo/USY and NiMo/SiO2–Al2O3. For hydrogenation of naphthalene, Pt/ITQ-2 displayed higher activity than Ptγ-Al2O3 and Pt/SiO2-Al2O3 but lower activity than Pt/USY with similar Pt dispersion. This is explained by considering that some of the Pt centers located in the 10 MR channels of ITQ-2 are not accessible to the naphthalene molecules. Indeed, Pt/ITQ-2 is significantly more active than Pt/USY for the hydrogenation of benzene, which can access the metal sites in the 10 MR channels of the delaminated ITQ-2 zeolite. Furthermore, Pt/ITQ-2 gave the highest aromatic reduction when using a hydrotreated light cycle oil (HT-LCO) feedstock containing ca. 70 vol% total aromatics, 0.40 wt% S, and 480 ppm N. In this case, the larger external surface area of ITQ-2 as compared with USY may favor the hydrogenation of the voluminous aromatic molecules present in the HT-LCO feed. These results can be explained by the peculiar structure of the delaminated ITQ-2 zeolite, which combines the good activity of zeolites with the desired selectivity of amorphous catalysts, while minimizing the diffusional problems often encountered in microporous materials.