Disclosed are a catalyst and a preparation method therefor, the catalyst being able to maintain a high production yield of C8 aromatic hydrocarbons in the process of converting a feedstock containing alkyl aromatics to C8 aromatic hydrocarbons such as mixed xylene through disproportionation/transalkylation/dealkylation while reducing a content of ethylbenzene in the products.

An efficient green method for the synthesis of noble metal/transition metal oxide nanocomposite comprising reducing noble metal salt and a templating metal oxide is disclosed. The method is a one-step method comprises mixing coffee seed husk extract, a noble metal precursor, and a transition metal precursor; and filtering and drying the nanocomposite. The nanocomposite prepared by the method of the invention displays all the characteristics and biocidal activity of a composite prepared by traditional methods.

The present disclosure provides for methods for designing and constructing metal/semiconductor heterostructures as catalysts for a wide range of applications such as oxygen activation. In a particular aspect, the present disclosure provides for the manipulation of atomic structures at MJ/TiO.sub.2 interface (e.g., Au/TiO.sub.2 interface) that significantly alters the interfacial electron distribution and prompts O.sub.2 activation. In an aspect, the present disclosure provides for a M/TiO.sub.2 composites (e.g., heterostructures) having a N defect-free M/TiO.sub.2 interface and method of making the M/TiO.sub.2 composites having a defect-free M/TiO.sub.2 interface. The M can be Au, Ag, Cu, Al, Pt, Ni, or Pd, for example.

Disclosed herein are modified zeolites and methods for making modified zeolites. In one or more embodiments disclosed herein, a modified zeolite may include a microporous framework comprising a plurality of micropores having diameters of less than or equal to 2 nm. The microporous framework may include at least silicon atoms and oxygen atoms. The modified zeolite may further include organometallic moieties each bonded to bridging oxygen atoms. The organometallic moieties may include a titanium atom. The titanium atom may be bonded to a bridging oxygen atom, and the bridging oxygen atom may bridge the titanium atom of the organometallic moiety and a silicon atom of the microporous framework.

Disclosed herein are modified zeolites and methods for making modified zeolites. In one or more embodiments disclosed herein, a modified zeolite may include a microporous framework comprising a plurality of micropores having diameters of less than or equal to 2 nm. The microporous framework may include at least silicon atoms and oxygen atoms. The modified zeolite may further include organometallic moieties each bonded to bridging oxygen atoms. The organometallic moieties may include a titanium atom. The titanium atom may be bonded to a bridging oxygen atom, and the bridging oxygen atom may bridge the titanium atom of the organometallic moiety and a silicon atom of the microporous framework.

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.

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.

A reverse water-gas shift catalyst that can be used at a high temperature is obtained, and a production method thereof is obtained. The reverse water-gas shift catalyst is obtained by at least supporting one or both of nickel and iron as a catalytically active component on a carrier containing a ceria-based metal oxide or a zirconia-based metal oxide as a main component, and a ratio of the carrier to the entire catalyst is 55% by weight or more.

A reverse water-gas shift catalyst that can be used at a high temperature is obtained, and a production method thereof is obtained. The reverse water-gas shift catalyst is obtained by at least supporting one or both of nickel and iron as a catalytically active component on a carrier containing a ceria-based metal oxide or a zirconia-based metal oxide as a main component, and a ratio of the carrier to the entire catalyst is 55% by weight or more.

The present invention relates to a metal powder catalyst and its use in the selective catalytic hydrogenation of organic starting materials comprising a carbon-carbon triple bond. The powder catalyst comprises a metal alloy carrier, wherein the metal alloy comprises (i) 55 weight-% (wt-%)-80 wt-%, based on the total weight of the metal alloy, of Co, and (ii) 20 wt-%-40 wt-%, based on the total weight of the metal alloy, of Cr, and (iii) 2 wt-%-10 wt-%, based on the total weight of the metal alloy, of Mo, and wherein the said metal alloy is coated by a metal oxide layer and impregnated with Pd, and is characterized in that the metal oxide layer comprises CeO.sub.2.