The invention relates to immobilized metal alkylidene catalysts. The catalysts are useful in olefin metathesis.

##STR00001##

A method, including: contacting a carbene or carbyne precatalyst with a first co-catalyst, under reaction conditions sufficient to cause the first-co-catalyst to activate the carbene or carbyne precatalyst, wherein the first co-catalyst is selected from the group consisting of an aluminum activator, a Br.sub.2-1,4-dioxane complex, I.sub.2, PhICl.sub.2, and PCl.sub.5.

The disclosure provides Group 6 complexes, which, in some embodiments, are useful for catalyzing olefin metathesis reactions. In some embodiments, the compounds are compounds of the following formula: ##STR00001## wherein: M is a Group 6 metal atom; X is an oxygen atom, ?NR.sup.5, ?NN(R.sup.5)(R.sup.5) or ?NOR.sup.5, R.sup.5 and R.sup.5 independently being various substituents, such as aryl or heteroaryl, each optionally substituted; n is 0 or 1; R.sup.z is a neutral ligand; R.sup.1 is hydrogen or an organic substituent; R.sup.2 is an aryl or heteroaryl group, each optionally substituted; R.sup.3 is an anionic ligand; and R.sup.4 is an anionic ligand, such as a pyrrolide, a pyrazolide, an imidazolide, an indolide, an azaindolide, or an indazolide, each optionally substituted.

A hydroprocessing catalyst or catalyst precursor has been developed. The catalyst is a unique transition metal tungsten oxy-hydroxide material. The hydroprocessing using the transition metal tungsten oxy-hydroxide material or the decomposition product thereof may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.

The invention concerns a method for manufacturing of an electrocatalyst comprising a porous carbon support material, a catalytic material in the form of at least one type of metal, and macrocyclic compounds chemically bound to the carbon support and capable of forming complexes with single metal ions of said metal or metals, said method comprising the steps of: i) providing a template capable of acting as pore structure directing agent during formation of a highly porous electrically conducting templated carbon substrate, ii) mixing the template with one or several precursor substances of the catalytic material, the macrocyclic compounds and carbon, iii) exposing the mixture of the template and the precursor substances to a carbonization process during which the precursors react and transform the mixture into a carbonized template composite in which the carbon part of the composite is chemically bound to macrocyclic compounds present in complexes with the metal or metals. The invention also concerns an electrocatalyst for electrochemical reactions, a method for manufacturing of a membrane electrode assembly using such an electrocatalyst and to a fuel cell making use of such an electrocatalyst.

A process for preparing a catalyst material, includes the steps of: (a) providing a support material having surface hydroxyl (OH) groups, wherein the support material is ceria (CeO.sub.2), zirconia (ZrO.sub.2) or a combination of thereof; (b) reacting the support material having surface hydroxyl (OH) groups of step (a) with a precursor containing two transition metal atoms, each chosen independently from the group consisting of: W, Mo, Cr, Ta, Nb, V, Mn; (c) calcining the product obtained in step (b) in order to provide a catalyst material showing dual site surface species containing pairs of transition metal atoms derived from the precursor that are present in oxide form on the support material. Additionally, a catalyst material is obtained by the process set out above, and the catalyst material is used as an ammonia selective catalytic reduction (NH.sub.3-SCR) catalyst for nitrogen oxides (NOx) reduction.

The precursor of a hydroprocessing catalyst is made by impregnating a metal oxide component comprising at least one metal from Group 6 of the Periodic Table and at least one metal from Groups 8-10 of the Periodic Table with an amide formed from a first organic compound containing at least one amine group, and a second organic compound containing at least one carboxylic acid group. Following impregnation heat treatment follows to form in situ generated unsaturation additional to that in the two organic compounds. The catalyst precursor is sulfided to form an active, sulfide hydroprocessing catalyst.

A tetraanionic OCO pincer ligand metal-oxo-alkylidene complex is prepared from a trianionic pincer ligand supported metal-alkylidyne. The metal can be tungsten or other group 5-7 transition metal. The tetraanionic pincer ligand metal-oxo-alkylidene complex, a trianionic OCO pincer ligand metal complex, or a trianionic ONO pincer ligand metal complex can be used to polymerize cycloalkenes. The poly(cycloalkene)s are predominantly cis-alkene macrocyclics.

The invention relates to an N-heterocyclic carbene complex of general formulas I to IV (I) (II) (III) (IV), according to which A1 stands for NR2 or PR2, A2 stands for CR2 R2, NR2, PR2, 0 or S, A3 stands for N or P, and C stands for a carbene carbon atom, ring B is an unsubstituted or a mono or poly-substituted 5 to 7-membered ring, substituents R2 and R2 stand, inter alia, for a linear or branched C1-Cw-alkyl group and, if N and N each stand for NR2 or PR2, are the same or different, M in formulas I, II, III or IV stands for Cr, Mo or W, X 1 or X2 in formulas I to IV are the same or different and represent, inter alia, C1-C1s carboxylates and C1-C1s-alkoxides, Y is inter alia oxygen or sulphur, Z is inter alia a linear or branched C1-Cw-alkylenoxy group, and R 1 and R1 in formulas I to IV are, inter alia, an aliphatic or aromatic group. These compounds are particularly suitable for use as catalysts for olefin metathesis reactions and have the advantage, compared to known Schrock carbene complexes, of displaying clearly increased tolerance to functional groups such as, in particular, aldehydes, secondary amines, nitriles, carboxylic acids and alcohols.

Method of forming an olefin from a first olefin and a second olefin in a metathesis reaction, comprising step (i): (i) reacting the first olefin with the second olefin in the presence of a silica supported Mo- or W-alkylidene catalyst, wherein the first olefin and the second olefin are different from one another.