A method of synthesizing a doped carbonaceous material includes mixing a carbon precursor material with at least one dopant to form a homogeneous/heterogeneous mixture; and subjecting the mixture to pyrolysis in an inert atmosphere to obtain the doped carbonaceous material. A method of purifying water includes providing an amount of the doped carbonaceous material in the water as a photocatalyst; and illuminating the water containing the doped carbonaceous material with visible light such that under visible light illumination, the doped carbonaceous material generates excitons (electron-hole pairs) and has high electron affinity, which react with oxygen and water adsorbed on its surface forming reactive oxygen species (ROS), such as hydroxyl radicals and superoxide radicals, singlet oxygen, hydrogen peroxide, that, in turn, decompose pollutants and micropollutants.

A method of synthesizing a doped carbonaceous material includes mixing a carbon precursor material with at least one dopant to form a homogeneous/heterogeneous mixture; and subjecting the mixture to pyrolysis in an inert atmosphere to obtain the doped carbonaceous material. A method of purifying water includes providing an amount of the doped carbonaceous material in the water as a photocatalyst; and illuminating the water containing the doped carbonaceous material with visible light such that under visible light illumination, the doped carbonaceous material generates excitons (electron-hole pairs) and has high electron affinity, which react with oxygen and water adsorbed on its surface forming reactive oxygen species (ROS), such as hydroxyl radicals and superoxide radicals, singlet oxygen, hydrogen peroxide, that, in turn, decompose pollutants and micropollutants.

A process includes reacting a feed stream containing ethanol and optionally acetaldehyde in a dehydration reactor in the presence of a dehydration catalyst system having a Group 4 or Group 5 metal oxide and a support. The process includes obtaining a product stream containing butadiene from the dehydration reactor. Another process includes reacting a feed stream containing ethanol and optionally acetaldehyde in a dehydration reactor in the presence of a dehydration catalyst system containing a tungsten oxide supported on a zeolite or a tantalum oxide supported on a zeolite. The process includes obtaining a product stream containing butadiene from the dehydration reactor.

A process includes reacting a feed stream containing ethanol and optionally acetaldehyde in a dehydration reactor in the presence of a dehydration catalyst system having a Group 4 or Group 5 metal oxide and a support. The process includes obtaining a product stream containing butadiene from the dehydration reactor. Another process includes reacting a feed stream containing ethanol and optionally acetaldehyde in a dehydration reactor in the presence of a dehydration catalyst system containing a tungsten oxide supported on a zeolite or a tantalum oxide supported on a zeolite. The process includes obtaining a product stream containing butadiene from the dehydration reactor.

The present invention relates to a hydrocarbon conversion catalyst comprising i) a catalyst, in oxidic form, metals M1, M2, M3 and M4, wherein: M1 is selected from Si, Al, Zr, and mixtures thereof; M2 is selected from Pt, Cr, and mixtures thereof; M3 is selected from W, Mo, Re and mixtures thereof; M4 is selected from Sn, K, Y, Yb and mixtures thereof; and ii) a hydrogen scavenger selected from at least one alkali and/or alkaline earth metal derivative, preferably in metallic, hydride, salt, complex or alloy form; as well as a hydrocarbon conversion process utilizing this catalyst.

An improved cluster-supporting catalyst has heteroatom-removed zeolite particles, and catalyst metal clusters supported within the pores of the heteroatom-removed zeolite particles. A method for producing a cluster-supporting catalyst includes the following steps: providing a dispersion liquid containing a dispersion medium and the heteroatom-removed zeolite particles dispersed in the dispersion medium; and in the dispersion liquid, forming catalyst metal clusters having a positive charge, and supporting the catalyst metal clusters within the pores of the heteroatom-removed zeolite particles through an electrostatic interaction.

The present invention relates to a stabilized rhenium-based heterogeneous catalyst, obtainable by a process comprising contacting a rhenium-based heterogeneous catalyst with a stabilizing agent at a temperature in a range from 0-100 C., the stabilizing agent comprising an aliphatic hydrocarbon compound and use thereof.

The present invention relates to a stabilized rhenium-based heterogeneous catalyst, obtainable by a process comprising contacting a rhenium-based heterogeneous catalyst with a stabilizing agent at a temperature in a range from 0-100 C., the stabilizing agent comprising an aliphatic hydrocarbon compound and use thereof.

A catalyst system is disclosed for producing para-xylene from a C.sub.8 hydrocarbon mixture comprising ethylbenzene and at least one xylene isomer other than para-xylene. The catalyst system comprises a first catalyst bed and a second catalyst bed. The first catalyst bed comprises a first zeolite and a rhenium hydrogenation component. The first zeolite has a constraint index from 1 to 12, an average crystal size from 0.1 to 1 micron and has been selectivated to have an ortho-xylene sorption time of greater than 1200 minutes based on its capacity to sorb 30% of the equilibrium capacity of ortho-xylene at 120? C. and an ortho-xylene partial pressure of 4.5?0.8 mm of mercury. The second catalyst bed comprises a second zeolite and a rhenium hydrogenation component. The second zeolite has a constraint index ranging from 1 to 12 and an average crystal size of less than 0.1 micron.

A catalyst system is disclosed for producing para-xylene from a C.sub.8 hydrocarbon mixture comprising ethylbenzene and at least one xylene isomer other than para-xylene. The catalyst system comprises a first catalyst bed and a second catalyst bed. The first catalyst bed comprises a first zeolite and a rhenium hydrogenation component. The first zeolite has a constraint index from 1 to 12, an average crystal size from 0.1 to 1 micron and has been selectivated to have an ortho-xylene sorption time of greater than 1200 minutes based on its capacity to sorb 30% of the equilibrium capacity of ortho-xylene at 120? C. and an ortho-xylene partial pressure of 4.5?0.8 mm of mercury. The second catalyst bed comprises a second zeolite and a rhenium hydrogenation component. The second zeolite has a constraint index ranging from 1 to 12 and an average crystal size of less than 0.1 micron.