A process for producing a catalytically active multielement oxide comprising the elements Mo, W, V and Cu, wherein at least one source of the elemental constituents W of the multielement oxide is used to produce an aqueous solution, the resultant aqueous solution is admixed with sources of the elemental constituents Mo and V of the multielement oxide, drying of the resultant aqueous solution produces a powder P, the resultant powder P is optionally used to produce geometric shaped precursor bodies, and the powder P is or the geometric shaped precursor bodies are subjected to thermal treatment to form the catalytically active composition, wherein the aqueous solution used for drying comprises from 1.6% to 5.0% by weight of W and from 7.2% to 26.0% by weight of Mo, based in each case on the total amount of aqueous solution.

A method is disclosed for preparing a slurry catalyst for use in upgrading a renewable feedstock. The method includes the steps of (a) providing a rework material obtained from a process of making a supported hydroprocessing catalyst, the hydroprocessing catalyst comprising a support and an active component supported thereon, wherein the rework material has an average particle size of from 1 to 300 m; (b) mixing the rework material with a liquid component to form a slurry catalyst precursor, wherein the liquid component is selected from the renewable feedstock and a liquid carrier, wherein the liquid carrier is a polyol and/or a recycled renewable feedstock comprising heavy and/or unconverted fractions from a slurry hydroprocessing process; and (c) sulfiding the slurry catalyst precursor forming the slurry catalyst.

A subject matter of the invention is a process for the hydrotreating of a hydrocarbon feedstock having a distillation range of between 150 C. and 600 C., so as to obtain a hydrotreated effluent, said process comprising the following stages: a) said hydrocarbon feedstock is brought into contact, in the presence of hydrogen, with at least one first catalyst occupying a volume V1 and comprising a support based on alumina or silica or silica-alumina and an active phase consisting of nickel and molybdenum, b) the effluent obtained in stage a) is brought into contact, in the presence of hydrogen, with at least one second catalyst occupying a volume V2 and comprising a support based on alumina or silica or silica-alumina and an active phase consisting of nickel, molybdenum and tungsten, and phosphorus,
the distribution of the volumes V1/V2 being of between 50% vol/50% vol and 90% vol/10% vol respectively.

A subject matter of the invention is a catalyst comprising a support and an active phase consisting of nickel, molybdenum and tungsten, and phosphorus, the nickel content, measured in the NiO form, is between 3% and 4% by weight; the molybdenum content, measured in the MoO.sub.3 form, is between 2% and 4% by weight; the tungsten content, measured in the WO.sub.3 form, is between 34% and 40% by weight; the phosphorus content, measured in the P.sub.2O.sub.5 form, is between 3% and 4% by weight, with respect to the total weight of the catalyst; the WO.sub.3/MoO.sub.3 molar ratio is between 5.3 and 12.4 mol/mol, the NiO/(WO.sub.3+MoO.sub.3) molar ratio is between 0.20 and 0.33 mol/mol and the P.sub.2O.sub.5/(WO.sub.3+MoO.sub.3) molar ratio is between 0.21 and 0.34 mol/mol. The invention also relates to its method of preparation and to its use in hydrotreating and/or hydrocracking.

The present invention relates to catalysts for producing an unsaturated carboxylic acid, containing: a catalytically active component represented by the following formula (1), in which the catalysts have a median diameter D50S (mm) 5.0 mm or more and 8.0 mm or less, and a relationship between a specific surface area A (m.sup.2/g) and the D50S (mm) is expressed by the following expression (2). (Mo).sub.12(V).sub.a(W).sub.b(Cu).sub.c(Sb).sub.d(X).sub.e(Y).sub.f(Z).sub.g(O).sub.h (1) 8.0D50SA20.0 (2).

Provided is a method for preparing a diol. In the method, a saccharide and hydrogen as raw materials are contacted with a catalyst in water to prepare the diol. The employed catalyst is a composite catalyst comprised of a main catalyst and a cocatalyst, wherein the main catalyst is a water-insoluble acid-resistant alloy; and the cocatalyst is a soluble tungstate and/or soluble tungsten compound. The method uses an acid-resistant, inexpensive and stable alloy needless of a support as a main catalyst, and can guarantee a high yield of the diol in the case where the production cost is relatively low.