Abstract: New sulfide metal catalysts are described, containing Ni, Mo and W, an element Z selected from Si, Al and mixtures thereof, and possibly an organic residue, obtained by sulfidation of mixed oxide precursors, also new, characterized in that they comprise an amorphous phase and a wolframite iso structural crystalline phase, the crystallinity degree of said mixed oxides being higher than 0 and lower than 100%, preferably higher than 0 and lower than 70%. The catalysts of the invention are useful as hydrotreatment catalysts, and in particular as hydrodesulfurization, hydrodenitrogenation and/or hydrodearomatization catalysts.

Abstract: New sulfided metal catalysts are described, containing a metal X selected from Ni, Co and mixtures thereof, a metal Y selected from Mo, W and mixtures thereof, an element Z selected from Si, Al and mixtures thereof, and possibly an organic residue, obtained by the sulfidation of mixed oxide precursors, also new, having general formula (A) XaYbZcOd.

Abstract: New sulfide metal catalysts are described, containing Ni, Mo and W, an element Z selected from Si, Al and mixtures thereof, and possibly an organic residue, obtained by sulfidation of mixed oxide precursors, also new, characterized in that they comprise an amorphous phase and a wolframite iso structural crystalline phase, the crystallinity degree of said mixed oxides being higher than 0 and lower than 100%, preferably higher than 0 and lower than 70%. The catalysts of the invention are useful as hydrotreatment catalysts, and in particular as hydrodesulfurization, hydrodenitrogenation and/or hydrodearomatization catalysts.

Abstract: New sulfided metal catalysts are described, containing a metal X selected from Ni, Co and mixtures thereof, a metal Y selected from Mo, W and mixtures thereof, an element Z selected from Si, Al and mixtures thereof, and possibly an organic residue, obtained by the sulfidation of mixed oxide precursors, also new, having general formula (A) Xa Yb Zc Od.

Abstract: New sulfided metal catalysts are described, containing a metal X selected from Ni, Co and mixtures thereof, a metal Y selected from Mo, W and mixtures thereof, an element Z selected from Si, Al and mixtures thereof, and possibly an organic residue, obtained by the sulfidation of mixed oxide precursors, also new, having general formula (A) XaYbZcOd.

Abstract: New sulfided metal catalysts are described, containing a metal X selected from Ni, Co and mixtures thereof, a metal Y selected from Mo, W and mixtures thereof, an element Z selected from Si, Al and mixtures thereof, and possibly an organic residue, obtained by the sulfidation of mixed oxide precursors, also new, having general formula (A) XaYbZcOd.

Abstract: The present invention provides a nickel cermet, which includes: 35% to 70% by weight of a nickel phase, and 65% to 30% by weight of zirconium oxide phase, wherein the zirconium oxide is stabilized in cubic form by 5 to 20 moles of yttrium oxide for each 100 moles of said zirconium oxide, and the metal nickel and zirconium oxide phases, upon X ray diffraction analysis are distinct and homogeneously distributed; and is prepared by a process that includes: a) dispersing zirconia stabilized by yttria having a particle size of between 1 and 40 &mgr;m , in demineralized water to prepare a suspension; b) dissolving a hydrosoluble and thermodecomposable nickel salt in demineralized d water to prepare a solution; c) mixing the nickel solution with the suspension and homogenizing the resulting dispersion by magnetic stirring for a time of between 5 and 40 minutes; d) eliminating the water from the dispersion by a system capable of operating without, or almost without, decomposition phenomena to obtain a solid th

Abstract: A nickel cermet containing a metal nickel phase and an yttria stabilized zirconia phase, is prepared by a process comprising: preparing a suspension of the zirconia in demineralized water; preparing a solution of a nickel salt in demineralized water; mixing the nickel solution and the zirconia dispersion; eliminating the water from the mixture to obtain a solid containing particles of the zirconia covered with the nickel salt; calcining the solid under oxidizing conditions to form particles of the zirconia covered with nickel oxide; and reducing the nickel oxide with hydrogen to nickel metal.