A kind of activation method of fluorination catalyst

Abstract

The invention relates to a fluorination catalyst activation method, which comprises: 1) drying, wherein a catalyst precursor is subjected to step-by-step drying at a temperature of 100-400 DEG C undera diluent gas flow; and 2) activating, wherein the activating is performed in three stages, the initial control stage a comprises that the temperature is adjusted to 100-300 DEG C after the drying, hydrogen fluoride is introduced under a diluent gas flow, and the reaction heat [delta]T does not exceed 40 DEG C during the introducing, the step-by-step activation stage b comprises that the mass flow of the hydrogen fluoride is adjusted after the reaction heat [delta]T is stable, a mass flow ratio of the diluent to the hydrogen fluoride is controlled within a certain rang, and step-by-step activation is performed, and the deep activation stage C is performed. According to the present invention, with the fluorination catalyst activation method, the damage of the sharp heat release on the structure of the catalyst can be avoided during the activating, the activated catalyst has the high fluorine content and the high specific surface area so as to provide the high catalytic activity, and the selectivity of R125 is up to more than 68% when the activated catalyst is used for the catalytic preparation of R125.

Description

technical field [0001] The invention relates to the technical field of preparation of fluorination catalysts, in particular to a method for activating the fluorination catalyst used in the gas-phase fluorination reaction of halogenated hydrocarbons and hydrogen fluoride. Background technique [0002] In the field of fluorine chemical industry, since the ozone depletion potential (ODP) of hydrofluorocarbons (HFCs) is 0, the global warming potential (GWP) is small, and the refrigeration performance is similar to that of chlorofluorocarbons (CFCs), it is an ideal choice for CFCs. Substitutes are widely used in large commercial refrigerants, blowing agents, fire extinguishing agents, etc. Gas-phase fluorine-chlorine exchange reaction is the key reaction for the selective synthesis of fluorine-containing compounds. It has been widely used in the industrial production process of hydrofluorocarbons because of its simplicity, economy and practicality, less pollution and easy operati...

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Problems solved by technology

[0004] However, the above-mentioned activation methods do not take into account the influence of reaction heat and temperature changes on the internal structure of the catalyst. Since the catalyst will undergo a violent heat release when it first contacts hydrogen fluoride, a sharp temperature rise may also occur during the activation process, and these mutations will be damaged to varying degrees. The internal structure of the catalyst affects the catalytic activity of the catalyst

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