Mesoporous (ZrO 2 –TiO 2 )/Al 2 O 3 ternary carriers as hydrodesulfurization catalysts support Carlos A. Ulı ´n a , Jose ´ A. De Los Reyes a,n , Jose ´ Escobar b,nn , Marı ´a C. Barrera b , Marı ´a A. Corte ´ s-Jacome b a Universidad Auto ´noma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, Iztapalapa, Me´xico, D. F. 09340, Me ´xico b Instituto Mexicano del Petro ´leo, Eje Central La ´zaro Ca ´rdenas 152, Col. San Bartolo Atepehuacan, Gustavo A. Madero, Me´xico, D. F. 07730, Me ´xico article info Article history: Received 30 October 2009 Received in revised form 4 March 2010 Accepted 2 April 2010 Keywords: A. Oxides C. Raman spectroscopy C. Thermogravimetric analysis (TGA) C. X-ray diffraction abstract Ternary systems at various compositions were synthesized by coprecipitating Zr and Ti (to get a ZrO 2 –TiO 2 40–60 mol%) chlorides in aqueous basic media (provided by urea thermal decomposition) over an alumina substrate. Materials characterization included N 2 physisorption, X-ray diffraction, thermal analysis, high-resolution electron microscopy and Raman and UV–vis spectroscopies. High interaction among components was clearly evidenced by various techniques. Textural properties of ternary oxides could be tuned depending on composition of formulations. Mixed oxides with 10 or 20 mol% of ZrO 2 –TiO 2 (at 40–60% mol, in turn) had the most suitable combination of textural properties (surface area, average pore diameter and pore volume) for the intended application (support of catalyst for hydrodesulfurization de oil-derived middle distillates). The suitability of those ternary supports was demonstrated in the dibenzothiophene hydrodesulfurization where the corresponding supported MoS 2 catalysts (at 2.8 atom Mo nm 2 ) were much more active (on a per mass of catalyst basis) than when impregnated over either alumina or zirconia–titania oxides. & 2010 Elsevier Ltd. All rights reserved. 1. Introduction Production of ultra-clean oil-derived fuels of very low S content (i.e., ultra-low sulfur diesel, ULSD) has encouraged numerous investigations focused on improving the currently available diesel hydrodesulfurization (HDS) processes. More efficient catalytic hydrotreating (HDT) operations are needed to obtain the aforementioned goal. One of the strategies followed to improve HDS catalysts consists in developing novel carriers that could contribute to obtaining enhanced properties (dispersion, sulfidability, promotion degree, stability, etc.) of supported sulfided CoMo or NiMo active phases. Recently, our group has reported [1–4] on the suitability of wide-pore ZrO 2 –TiO 2 mixed oxides (at 30–70 mol ratio, obtained by solvo-thermal post-treatment during sol–gel processing) as support of sulfided CoMo or NiMo catalysts applied in the dibenzothiophene HDS. It is worth mentioning that the solvo- thermal technique was applied to overcome textural drawbacks related to limited pore size (in the 3–5 nm range, after calcination at 500 1C) commonly found in zirconia–titania oxides. It has been shown that ZrO 2 –TiO 2 binary systems with pores size distribution centered at 8–10 nm (materials solvo-treated at 80 1C and calcined at 500 1C [1–4]) combine suitable surface properties with tailor- made texture. Those characteristics allowed one to obtain suitable carriers for catalyst to be applied in the conversion of organo-S compounds present in oil-derived middle distillates. It is worth mentioning that due to the kinetic diameter of those species, diffusional limitations could control the process if catalysts carriers of reduced pore size are utilized, with the consequent active sites under-utilization. Accelerated deactivation by pore plugging due to carbon deposition could also be an issue in HDS catalysts of reduced pore size [5], causing shortened catalyst life cycle. High surface area (S g Z300 m 2 g 1 ) also proves crucial in carriers to be applied in the development of catalyst for ULSD production, taking into account the necessity of efficiently dispersing sulfided active phases to obtain the highest attainable organo-S compounds conversion at given conditions. In addition, high pore volume (V p Z0.7 ml g 1 ) in materials to be used as HDS catalysts carrier could positively influence sulfided Co (or Ni) and Mo dispersion, enabling the use of less concentrated solutions (during pore-filling impregnation) to obtain a given target loading. A support possessing the right combination of textural properties (S g , average pore diameter and V p ) could strongly potentiate the hydrodesulfurizating properties of sulfided CoMo or NiMo formulations [6]. Continuing in our search for zirconia–titania supports of improved textural properties, we tried a different approach in the present investigation: ZrO 2 –TiO 2 deposition over an Al 2 O 3 substrate. Other authors have synthesized ZrO 2 –TiO 2 –Al 2 O 3 ternary formula- tions being focused on enhancing the thermal resistance of the first two components, in mixed oxide systems applied in the ARTICLE IN PRESS Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/jpcs Journal of Physics and Chemistry of Solids 0022-3697/$ - see front matter & 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jpcs.2010.04.003 n Corresponding author. Tel.: + 52 55 58044601; fax: + 52 55 56122479. nn Corresponding author. Tel.: + 52 55 9175 8389; fax: + 52 55 9175 6380. E-mail addresses: jarh@xanum.uam.mx (J.A. De Los Reyes), jeaguila@imp.mx (J. Escobar). Journal of Physics and Chemistry of Solids 71 (2010) 1004–1012