The present invention relates to the field of catalysts, and provides a porous layered transition metal dichalcogenide (TMD) and a preparation method and use thereof. The preparation method includes the following steps: (1) mixing silica microspheres, a transition metal salt and an elemental chalcogen, and pressing to obtain a tablet, the silica microspheres having a same or different particle diameters; and (2) sintering the tablet under hydrogen, and removing the silica microspheres to obtain the porous layered TMD. The porous layered TMD prepared by the method of the present invention has a high lattice edge exposure, which provides more active sites and higher catalytic activity, so the porous layered TMD can effectively catalyze the oxidation of alcohols to aldehydes or sulfides to sulfoxides under visible light irradiation.

The present invention relates to the field of catalysts, and provides a porous layered transition metal dichalcogenide (TMD) and a preparation method and use thereof. The preparation method includes the following steps: (1) mixing silica microspheres, a transition metal salt and an elemental chalcogen, and pressing to obtain a tablet, the silica microspheres having a same or different particle diameters; and (2) sintering the tablet under hydrogen, and removing the silica microspheres to obtain the porous layered TMD. The porous layered TMD prepared by the method of the present invention has a high lattice edge exposure, which provides more active sites and higher catalytic activity, so the porous layered TMD can effectively catalyze the oxidation of alcohols to aldehydes or sulfides to sulfoxides under visible light irradiation.

The present invention relates to the field of catalysts, and provides a porous layered transition metal dichalcogenide (TMD) and a preparation method and use thereof. The preparation method includes the following steps: (1) mixing silica microspheres, a transition metal salt and an elemental chalcogen, and pressing to obtain a tablet, the silica microspheres having a same or different particle diameters; and (2) sintering the tablet under hydrogen, and removing the silica microspheres to obtain the porous layered TMD. The porous layered TMD prepared by the method of the present invention has a high lattice edge exposure, which provides more active sites and higher catalytic activity, so the porous layered TMD can effectively catalyze the oxidation of alcohols to aldehydes or sulfides to sulfoxides under visible light irradiation.

A catalyst may suppress pressure loss and coaking and produce a target substance in high yield when a gas-phase catalytic oxidation reaction of a material substance is conducted using the catalyst to produce the target substance. A ring-shaped catalyst may have a straight body part and a hollow body part, which is used when a gas-phase catalytic oxidation reaction of a material substance is conducted to produce a target substance, wherein a length of the straight body part is shorter than a length of the hollow body part and at least at one end part, a region from an end part of the straight body part to an end part of the hollow body part is concavely curved.

There is provided a catalyst having an average electronegativity of 2.1 or more and 2.8 or less.

There is provided a catalyst having an average electronegativity of 2.1 or more and 2.8 or less.

The present invention provides a process for preparing a (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3), wherein R represents a linear or branched alkyl group having 1 to 4 carbon atoms, the process comprising subjecting a haloacetaldehyde alkyl 2,3-dimethyl-2-cyclopentenyl acetal compound of the following general formula (1), wherein R is as defined above, and Y represents a halogen atom, to a dehydrohalogenation reaction in the presence of a base, followed by a rearrangement reaction to obtain a (1,2-dimethyl-2-cyclopentenyl)acetate compound of the following general formula (2), wherein R is as defined above, and subjecting the (1,2-dimethyl-2-cyclopentenyl)acetate compound (2) to an epoxidation reaction, followed by an isomerization reaction and then a methylenation reaction to obtain the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3). The present invention also provides a process for preparing (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde of the following formula (4), the process comprising the aforesaid process for preparing the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3), and converting an alkoxycarbonylmethyl group (i.e., —CH.sub.2C(═O)OR) of the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3) to a formylmethyl group (i.e., —CH.sub.2CHO) to obtain (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde (4).

##STR00001##

The present invention provides a process for preparing a (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3), wherein R represents a linear or branched alkyl group having 1 to 4 carbon atoms, the process comprising subjecting a haloacetaldehyde alkyl 2,3-dimethyl-2-cyclopentenyl acetal compound of the following general formula (1), wherein R is as defined above, and Y represents a halogen atom, to a dehydrohalogenation reaction in the presence of a base, followed by a rearrangement reaction to obtain a (1,2-dimethyl-2-cyclopentenyl)acetate compound of the following general formula (2), wherein R is as defined above, and subjecting the (1,2-dimethyl-2-cyclopentenyl)acetate compound (2) to an epoxidation reaction, followed by an isomerization reaction and then a methylenation reaction to obtain the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3). The present invention also provides a process for preparing (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde of the following formula (4), the process comprising the aforesaid process for preparing the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3), and converting an alkoxycarbonylmethyl group (i.e., —CH.sub.2C(═O)OR) of the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3) to a formylmethyl group (i.e., —CH.sub.2CHO) to obtain (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde (4).

##STR00001##

Disclosed herein are embodiments of a method and system for converting ethanol to para-xylene. The method also provides a pathway to produce terephthalic acid from biomass-based feedstocks. In some embodiments, the disclosed method produces p-xylene with high selectivity over other aromatics typically produced in the conversion of ethanol to xylenes, such as m-xylene, ethyl benzene, benzene, toluene, and the like. And, in some embodiments, the method facilitates the ability to use ortho/para mixtures of methylbenzyaldehyde for preparing ortho/para xylene product mixtures that are amendable to fractionation to separate the para- and ortho-xylene products thereby providing a pure feedstock of para-xylene that can be used to form terephthalic anhydride and a pure feedstock of ortho-xylene that can be used for other purposes, such as phthalic anhydride.

Disclosed herein are embodiments of a method and system for converting ethanol to para-xylene. The method also provides a pathway to produce terephthalic acid from biomass-based feedstocks. In some embodiments, the disclosed method produces p-xylene with high selectivity over other aromatics typically produced in the conversion of ethanol to xylenes, such as m-xylene, ethyl benzene, benzene, toluene, and the like. And, in some embodiments, the method facilitates the ability to use ortho/para mixtures of methylbenzyaldehyde for preparing ortho/para xylene product mixtures that are amendable to fractionation to separate the para- and ortho-xylene products thereby providing a pure feedstock of para-xylene that can be used to form terephthalic anhydride and a pure feedstock of ortho-xylene that can be used for other purposes, such as phthalic anhydride.