Highly active MoS2 on wide-pore ZrO2-TiO2 mixed oxides

Wide-pore ZrO2-TiO2 (Zr/Ti = 30/70) was prepared by low-temperature (273 K) sol-gel technique followed by solvo-treatment. Higher surface area (S-g similar to 340 m(2) g(-1)) and porosity (V-p similar to 0.8 cm(3) g(-1)) were registered after solvo-treatment at 353 K (1 day) for samples calcined at 773 K. Wider pores (similar to22 nm) but much lower Sg (similar to80 m(2) g(-1))were observed when solvo-treatment was carried out at 513 K. Even larger pores with almost no additional Sg decrease were obtained by prolonging that stage. MoS2 catalysts supported on binary oxides solvo-treated at 353 K showed increased intrinsic activity (by a factor of similar to3.3) in dibenzothiophene hydrodesulfurization (593 K and 5.6 MPa), as to that impregnated on conventional ZrO2-TiO2 (at 2.8 Mo atoms nm(-2)). By itself, Mo sulfidability (as determined by XPS) seemed not to dictate the activity trends found. Surface Lewis acidity appeared to play a decisive role on HDS performance, probably by influencing both Mo sulfidability and dispersion. Highly-loaded catalysts (5.6 Mo atoms nm(-2)) had decreased activity, probably due to lower MoS2 dispersion. Additional characterization comprised chemical analysis (ICP), XRD, thermal analysis, acidity measurements (by pyridine FTIR) and UV-vis DRS. Tailoring ZrO2-TiO2 texture, traditionally characterized by narrow micro-mesoporosity results promising in developing novel hydrotreating catalyst supports. (C) 2004 Elsevier B.V. All rights reserved.