Highly active sulfided CoMo catalysts supported on (ZrO 2 eTiO 2 )/Al 2 O 3 ternary oxides José Escobar a, * , José A. De Los Reyes b , Carlos A. Ulín b , María C. Barrera c a Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas 152, Col. San Bartolo Atepehuacan, Gustavo A. Madero, México, D.F. 07730, Mexico b Area de Ing. Química, UAM e Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, Iztapalapa, México, D.F. 09340, Mexico c Facultad de Ciencias Químicas, Universidad Veracruzana, Av. Universidad km. 7.5, Col. Santa Isabel, Coatzacoalcos, Veracruz, México, D.F. 96538, Mexico highlights  High HDS activity of sulfided CoMo catalysts supported on (ZrO 2 eTiO 2 )/Al 2 O 3 .  Enhanced activity in HDS of dibenzothiophene and 4,6-dimethyl-dibenzothiophene.  Low proportion of tetrahedral Mo 6þ over impregnated precursor with ternary carrier.  Ternary support combines texture of Al 2 O 3 with ZrO 2 eTiO 2 surface properties. article info Article history: Received 24 September 2012 Received in revised form 5 July 2013 Accepted 30 August 2013 Keywords: Oxides Precipitation Amorphous materials Raman spectroscopy and scattering Chemisorption Powder diffraction abstract (ZrO 2 eTiO 2 )/Al 2 O 3 ternary oxide at 20 mol% Al 2 O 3 (80% ZrO 2 eTiO 2 , in turn at 40e60 mol ratio) prepared by controlled co-precipitation (by urea thermal decomposition) of zirconium (ZrOCl 2 $8H 2 O) and tita- nium (TiCl 4 ) chlorides over a ground alumina substrate constitutes a promising material to be used as carrier of sulfided hydrodesulfurization (HDS) catalysts. After calcining (at 500  C), the ternary oxide presented textural properties (S g ¼ 387 m 2 g 1 , V p ¼ 0.74 ml g 1 , mean pore diameter ¼ 7.6 nm) suitable to its utilization as carrier of catalysts applied in the oil-derived middle distillates HDS. As determined by temperature programmed-reduction and Raman and UVevis spectroscopies ZrO 2 eTiO 2 deposition over alumina substrate resulted in decreased proportion of Mo 6þ species in tetrahedral coordination on the oxidic impregnated material. As those species constitute hardly reducible precursors, their diminished concentration could be reflected in enhanced amount of Mo species susceptible of activation by sulfiding (H 2 S/H 2 at 400  C) over our ternary carrier. Limiting the concentration of zirconia-titania (at 40e60 mol ratio) to 20 mol% in the mixed oxides support allowed the preparation of highly active promoted (by cobalt, at Co/(Co þ Mo) ¼ 0.3) MoS 2 phase (at 2.8 atoms/nm 2 ), that formulation showing excellent properties in hydrodesulfurization (HDS) of both dibenzothiophene and highly-refractory 4,6-dimethyl- dibenzothiophene. Due to alike yields to various HDS products over CoMo/(ZrO 2 eTiO 2 )/Al 2 O 3 and the corresponding Al 2 O 3 -supported formulation, presence of similar actives sites over those catalysts was strongly suggested. It seemed that enhanced concentration of octahedral Mo 6þ over the oxidic impregnated precursor with (ZrO 2 eTiO 2 )/Al 2 O 3 ternary carrier resulted, after sulfiding, in increased amount of MoS 2 phase that could be efficiently promoted by cobalt. Ó 2013 Elsevier B.V. All rights reserved. 1. Introduction Demanded production of ultra-low sulfur diesel (ULSD) has encouraged numerous investigations focused in improving currently available oil-derived middle distillates hydrodesulfurization (HDS) processes. In this line, one of the strategies followed to get more efficient hydrotreating catalysts consists in developing novel carriers that could contribute in obtaining enhanced properties (dispersion, sulfidability, promotion degree, stability, etc.) of supported sulfided CoMo or NiMo active phases. In that context, our group has already reported on the suitability of wide-pore ZrO 2 eTiO 2 mixed oxides (obtained by solvo-thermal post-treatment during solegel process- ing) as support of sulfided CoMo [1] or NiMo catalysts [2] applied in the dibenzothiophene (DBT) HDS. It is worth mentioning that DBT * Corresponding author. Tel.: þ52 55 9175 8389. E-mail addresses: jeaguila@imp.mx, joseescobara@gmail.com (J. Escobar), jarh@ xanum.uam.mx (J.A. De Los Reyes), mcbdgavilan@gmail.com (M.C. Barrera). Contents lists available at ScienceDirect Materials Chemistry and Physics journal homepage: www.elsevier.com/locate/matchemphys 0254-0584/$ e see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.matchemphys.2013.08.054 Materials Chemistry and Physics xxx (2013) 1e10 Please cite this article in press as: J. Escobar, et al., Highly active sulfided CoMo catalysts supported on (ZrO 2 eTiO 2 )/Al 2 O 3 ternary oxides, Materials Chemistry and Physics (2013), http://dx.doi.org/10.1016/j.matchemphys.2013.08.054