A method for producing a tetrafluoroolefin, such as 2,3,3,3-tetrafluoropropene (HFO-1234yf), comprises dehydrofluorinating a pentafluoroalkane in a gas phase in the presence of a catalyst comprising chromium oxyfluoride. In a preferred embodiment, 2,3,3,3-tetrafluoropropene (HFO-1234yf) is produced by forming a catalyst comprising chromium oxyfluoride by calcining CrF.sub.3.xH.sub.2O, where x is 1-10, in the presence of a flowing gas comprising nitrogen to form a calcined chromium oxyfluoride, and dehydrofluorinating 1,1,1,2,2-pentafluoropropane (HFC-245cb) in a gas phase in the presence of the catalyst to form the 2,3,3,3-tetrafluoropropene (HFO-1234yf).

A method for producing a tetrafluoroolefin, such as 2,3,3,3-tetrafluoropropene (HFO-1234yf), comprises dehydrofluorinating a pentafluoroalkane in a gas phase in the presence of a catalyst comprising chromium oxyfluoride. In a preferred embodiment, 2,3,3,3-tetrafluoropropene (HFO-1234yf) is produced by forming a catalyst comprising chromium oxyfluoride by calcining CrF.sub.3.xH.sub.2O, where x is 1-10, in the presence of a flowing gas comprising nitrogen to form a calcined chromium oxyfluoride, and dehydrofluorinating 1,1,1,2,2-pentafluoropropane (HFC-245cb) in a gas phase in the presence of the catalyst to form the 2,3,3,3-tetrafluoropropene (HFO-1234yf).

The present disclosure provides a method for conversion of a mixture of high-boiling fluorinated components comprising 1,1,3,3-tetrachloro-1-fluoropropane (HCFC-241fa), 1,3,3-trichloro-1,1-difluoropropane (HCFC-242sfa), 1,1,3-trichloro-1,3-difluoropropane (HCFC-242fb), 3,3-dichloro-1,1,1-trifluoropropane (HCFC-243fa), 1,3-dichloro-1,1,3-trifluoropropane (HCFC-243fb), 3-chloro-1,1,1,3-tetrafluoropropane (HCFC-244fa), their isomers, and combinations thereof, to 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd). Heavy impurities, such as oligomers and other high boiling impurities, that are present may be purged during the process to prevent yield loss and reduction of catalyst efficacy.

The present disclosure provides a method for conversion of a mixture of high-boiling fluorinated components comprising 1,1,3,3-tetrachloro-1-fluoropropane (HCFC-241fa), 1,3,3-trichloro-1,1-difluoropropane (HCFC-242sfa), 1,1,3-trichloro-1,3-difluoropropane (HCFC-242fb), 3,3-dichloro-1,1,1-trifluoropropane (HCFC-243fa), 1,3-dichloro-1,1,3-trifluoropropane (HCFC-243fb), 3-chloro-1,1,1,3-tetrafluoropropane (HCFC-244fa), their isomers, and combinations thereof, to 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd). Heavy impurities, such as oligomers and other high boiling impurities, that are present may be purged during the process to prevent yield loss and reduction of catalyst efficacy.

Aspects disclosed herein include a system for generating singlet oxygen in a gas, the system comprising: a substrate; and hexanuclear clusters operably immobilized on at least a portion of the substrate; wherein each hexanuclear cluster comprises a photosensitive octahedral core complex characterized by formula FX1a: M.sub.6X.sub.8 (FX1a); wherein each M is independently Mo, W, or Re; wherein each X is independently a halide anion ligand; wherein the clusters are exposed to the gas and the gas comprises O.sub.2 gas; wherein the clusters are exposed to a light; and wherein each hexanuclear cluster is a photosensitizer configured to generate the gaseous singlet oxygen when irradiated by the light in the presence of the O.sub.2 gas.

Aspects disclosed herein include a system for generating singlet oxygen in a gas, the system comprising: a substrate; and hexanuclear clusters operably immobilized on at least a portion of the substrate; wherein each hexanuclear cluster comprises a photosensitive octahedral core complex characterized by formula FX1a: M.sub.6X.sub.8 (FX1a); wherein each M is independently Mo, W, or Re; wherein each X is independently a halide anion ligand; wherein the clusters are exposed to the gas and the gas comprises O.sub.2 gas; wherein the clusters are exposed to a light; and wherein each hexanuclear cluster is a photosensitizer configured to generate the gaseous singlet oxygen when irradiated by the light in the presence of the O.sub.2 gas.

Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650 C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.

A method for activating a catalyst comprises the steps of: a) optionally drying the catalyst at a temperature of from 100 C. to 400 C.; b) treating the catalyst with a composition comprising HF at a temperature of from 0 C. to about 500 C.; c) treating the catalyst with a composition comprising an oxidant and optionally HF at a temperature of from about 100 C. to about 500 C.

An object of the present invention is to provide a novel method for producing 3-chloro-1,1,1,5,5,5-hexafluoro-2-pentene. Provided is a method for producing 3-chloro-1,1,1,5,5,5-hexafluoro-2-pentene, comprising a step of reacting 1,1,1,3,3,5,5,5-octachloropentane with hydrogen fluoride. Also provided are a method for producing 3-chloro-1,1,1,5,5,5-hexafluoro-2-pentene, comprising a step of reacting 1,1,3-trichloro-5,5,5-trifluoro-1,3-pentadiene with hydrogen fluoride, and a method for producing 3-chloro-1,1,1,5,5,5-hexafluoro-2-pentene, comprising a step of reacting 1,1,3,5,5,5-hexachloro-1,3-pentadiene with hydrogen fluoride.

Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650 C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.