This invention relates to a method for preparing 1,2-difluoroethylene and/or 1,1,2-trifluoroethane, comprising a step of performing at least one fluorination reaction by bringing at least one halide selected from the group consisting of haloethanes represented by general formula (1) CHX.sup.1X.sup.2CH.sub.2X.sup.3 (wherein X.sup.1, X.sup.2, and X.sup.3 are the same or different, and represent Cl, Br, or F) and haloethylenes represented by general formula (2) CHX.sup.4═CHX.sup.5 (wherein X.sup.4 and X.sup.5 are the same or different, and represent Cl, Br or F, with the proviso that the case in which X.sup.4 and X.sup.5 are both F is excluded).

A method of separating 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a) includes providing an untreated composition including 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a). The untreated composition is treated with an adsorbent to form a treated composition in which the concentration of 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a) is less than 93 percent of the concentration of the 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a) in the untreated composition based on a treatment time of 24 hours.

A method of separating 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a) includes providing an untreated composition including 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a). The untreated composition is treated with an adsorbent to form a treated composition in which the concentration of 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a) is less than 93 percent of the concentration of the 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a) in the untreated composition based on a treatment time of 24 hours.

A new chromium-containing fluorination catalyst is described. The catalyst comprises an amount of zinc that promotes activity. The zinc is contained in aggregates which have a size across their largest dimension of up to 1 micron. The aggregates are distributed throughout at least the surface region of the catalyst and greater than 40 weight % of the aggregates contain a concentration of zinc that is within ±1 weight % of the modal concentration of zinc in those aggregates.

A new chromium-containing fluorination catalyst is described. The catalyst comprises an amount of zinc that promotes activity. The zinc is contained in aggregates which have a size across their largest dimension of up to 1 micron. The aggregates are distributed throughout at least the surface region of the catalyst and greater than 40 weight % of the aggregates contain a concentration of zinc that is within ±1 weight % of the modal concentration of zinc in those aggregates.

A new chromium-containing fluorination catalyst is described. The catalyst comprises an amount of zinc that promotes activity and from 0.1 to 8.0% by weight of the chromium in the catalyst based on the total weight of the chromium is present as chromium (VI). The use of the zinc-promoted, chromium-containing catalyst in a fluorination process in which a hydrocarbon or halogenated hydrocarbon is reacted with hydrogen fluoride in the vapour-phase at elevated temperatures is also described.

A new chromium-containing fluorination catalyst is described. The catalyst comprises an amount of zinc that promotes activity and from 0.1 to 8.0% by weight of the chromium in the catalyst based on the total weight of the chromium is present as chromium (VI). The use of the zinc-promoted, chromium-containing catalyst in a fluorination process in which a hydrocarbon or halogenated hydrocarbon is reacted with hydrogen fluoride in the vapour-phase at elevated temperatures is also described.

The present invention relates to a process for modifying the fluorine distribution in a hydrocarbon compound in the presence of a catalyst, characterized by the use, as catalyst, of a solid composition comprising at least one component containing chromium oxyfluoride or fluoride of empirical formula Cr.sub.xM.sub.(1-x)O.sub.rF.sub.s, where 2r+s is greater than or equal to 2.9 and less than 6, M is a metal chosen from columns 2 to 12 of the Periodic Table of the Elements, x has a value from 0.9 to 1, s is greater than 0 and less than or equal to 6 and r is greater than or equal to 0 and less than 3, the said solid composition having a crystallinity of less than 20% by weight. The present invention also relates to the solid composition per se.

The present invention relates to a process for modifying the fluorine distribution in a hydrocarbon compound in the presence of a catalyst, characterized by the use, as catalyst, of a solid composition comprising at least one component containing chromium oxyfluoride or fluoride of empirical formula Cr.sub.xM.sub.(1-x)O.sub.rF.sub.s, where 2r+s is greater than or equal to 2.9 and less than 6, M is a metal chosen from columns 2 to 12 of the Periodic Table of the Elements, x has a value from 0.9 to 1, s is greater than 0 and less than or equal to 6 and r is greater than or equal to 0 and less than 3, the said solid composition having a crystallinity of less than 20% by weight. The present invention also relates to the solid composition per se.

The present application discloses compositions comprising hydrogen fluoride and fluorinated compounds (e.g., hydrochlorofluorocarbons), wherein the fluorinated compound is present in the composition in an amount effective to form an azeotrope composition or azeotrope-like composition with the hydrogen fluoride.