Epoxidation methods and catalyst are described herein. The epoxidation catalysts generally include a metal component including silver and a support material including kaolinite, wherein the epoxidation catalyst includes less than 55 wt. % metal component.

Methods are described for formation of a promoted catalysts. Promoted catalysts include metal oxide promoted silver catalysts for use in ethylene oxide production. Methods utilize a combination of relative surface free energies of catalyst and promoter materials, promoter loading concentrations, and calcination temperatures to encourage deposition and diffusion of promoters on catalyst metals of supported catalysts.

The present disclosure generally relates to a silver-based epoxidation catalyst. In certain embodiments, a method is provided for modulating the reactivity of the silver-based epoxidation catalyst, comprising the catalyst being post-treated with at least two different salt solutions. In some embodiments, the treatment results in the deposition of one or more metals onto the surface of the catalyst. In further embodiments, method is also provided of using the silver catalyst to generate an epoxide from an olefin.

An oxidative coupling of methane (OCM) catalyst composition comprising one or more oxides doped with Ag; wherein one or more oxides comprises a single metal oxide, mixtures of single metal oxides, a mixed metal oxide, mixtures of mixed metal oxides, or combinations thereof; and wherein one or more oxides is not La.sub.2O.sub.3 alone. A method of making an OCM catalyst composition comprising calcining one or more oxides and/or oxide precursors to form one or more calcined oxides, wherein the one or more oxides comprises a single metal oxide, mixtures of single metal oxides, a mixed metal oxide, mixtures of mixed metal oxides, or combinations thereof, wherein the one or more oxides is not La.sub.2O.sub.3 alone, and wherein the oxide precursors comprise oxides, nitrates, carbonates, hydroxides, or combinations thereof; doping the one or more calcined oxides with Ag to form the OCM catalyst composition; and thermally treating the OCM catalyst composition.

A preparation method of perovskite catalyst, represented by the following Chemical Formula 1: La.sub.xAg.sub.(1-x)MnO.sub.3 (0.1x0.9), includes the steps of 1) preparing a metal precursor solution including a lanthanum metal precursor, a manganese metal precursor and a silver metal precursor, 2) adding maleic or citric acid to the metal precursor solution, 3) drying the mixture separately several times with sequentially elevating the temperature in the range of 160 to 210 C., and 4) calcining the dried mixture at 600 to 900 C. for 3 hours to 7 hours.

Provided is a method capable of producing an olefin with high selectivity and high yield using a vicinal diol as a raw material. A method for producing an olefin includes a step of reacting a compound including two adjacent carbon atoms each containing a hydroxy group with hydrogen and forming an olefin, and in this step, the reaction of the compound including two adjacent carbon atoms each containing a hydroxy group with the hydrogen proceeds in the presence of a catalyst under a condition substantially free of a solvent. The catalyst includes a carrier, at least one oxide supported on the carrier and selected from the group consisting of oxides of group-6 elements and oxides of group-7 elements, and at least one metal supported on the carrier and selected from the group consisting of silver, iridium, and gold.

A carrier for an ethylene epoxidation catalyst, the carrier comprising a porous alumina body formed of sintered particles of alumina in a substantial absence of inorganic binder species other than alumina, wherein the substantial absence of inorganic binder species corresponds to an amount of less than 0.6 wt % inorganic binder species other than alumina and comprises at least a substantial absence of silicon-containing species.

A process for producing a silver-based epoxidation catalyst, comprising i) impregnating a particulate porous refractory support with a first aqueous silver impregnation solution comprising silver ions and an aminic complexing agent selected from amines, alkanolamines and amino acids; ii) converting at least part of the silver ions impregnated on the refractory support to metallic silver by heating while directing a stream of a first gas over the impregnated refractory support to obtain an intermediate catalyst, wherein the first gas comprises at least 5 vol.-% oxygen; iii) impregnating the intermediate catalyst with a second aqueous silver impregnation solution comprising silver ions, an aminic complexing agent selected from amines, alkanolamines and amino acids, and one or more transition metal promoters, in particular rhenium; and iv) converting at least part of the silver ions impregnated on the intermediate catalyst to metallic silver by heating while directing a stream of a second gas over the impregnated intermediate catalyst to obtain the epoxidation catalyst, wherein the second gas comprises at most 2.0 vol.-% oxygen, wherein the impregnated refractory support and the impregnated intermediate catalyst are each heated to a temperature of 200 to 800 C. The process of the invention surprisingly allows for obtaining a catalyst with high selectivity in a cost-efficient manner. The invention also relates to a silver-based epoxidation catalyst obtainable by such a process, and to a process for producing an alkylene oxide by gas-phase oxidation of an alkylene, comprising reacting an alkylene and oxygen in the presence of a silver-based epoxidation catalyst obtainable by the above process.

An ethylene oxide (EO) production process for the epoxidation of ethylene comprising: contacting an inlet feed gas with a catalyst having a fluoride-mineralized alpha-alumina carrier, silver, a rhenium promoter, and one or more alkali metal promoters. At a cumulative EO production cumEO.sub.1 of at least 0.2 kton EO/m.sup.3 catalyst, the process is operating at a reaction temperature T.sub.1 and with the inlet feed gas having an optimum overall catalyst chloriding effectiveness value Cl.sub.eff.sub.1 to produce EO with an EO production parameter value EO.sub.1; and the process is subsequently operated such that at a cumulative EO production cumEO.sub.X, cumEO.sub.X is at least 0.6 kton EO/m.sup.3 catalyst greater than cumEO.sub.1, the reaction temperature has an increased value T.sub.X to maintain EO production parameter EO.sub.1 whilst the optimum overall catalyst chloriding effectiveness value of the inlet feed gas Cl.sub.eff.sub.X is controlled such that the ratio of Cl.sub.eff.sub.X/Cl.sub.eff.sub.1 is from 0.8 to 1.2.