| abstract |
A method for activating a catalyst comprising: optionally drying the catalyst at a temperature of from 100 °C to 400 °C; treating the catalyst with a composition comprising HF at a temperature of from 100 °C to about 500 °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. The oxidant may be air, oxygen, chlorine, chlorine monofluoride or nitrogen trifluoride. The catalyst may be chromia and may also comprise zinc or zinc oxide. A method for activating a catalyst comprising: optionally drying the catalyst at a temperature of from 100 °C to 400 °C; treating the catalyst with a composition comprising HF at a temperature of from 500 °C to about 700 °C. The use of said activated catalyst in a fluorination or hydrofluorination reaction which may be performed on a halogenated hydrocarbon. The halogenated hydrocarbon may be 2-chloro-3,3,3-trifluoropropene (1233xf). A process for preparing a fluorinated hydrocarbon (e.g., 1234yf) comprising reacting an optionally halogenated hydrocarbon with hydrogen fluoride in the presence of said catalyst, wherein the process is carried out in vapour phase. |