▎ 摘　　要

NOVELTY - Initiator is claimed. The initiator is obtained through the initiator precursor composed of iron element and carrier, and the mass ratio of iron element and carrier is 5-30%:70-95%; carrier is activated carbon, molecular sieve, silicon dioxide, silicon carbide, graphite, and graphene; initiator is prepared by iron element and carrier, impregnating the soluble salt of iron element on the carrier, filtering to obtain the initiator precursor, then drying initiator precursor, calcining and activating to obtain initiator. USE - The initiator is useful for preparing hydrochlorofluorocarbons from halogenated alkenes and halogenated alkanes, and in preparing hydrofluoroolefins by gas-phase continuous reaction (all claimed). ADVANTAGE - The method not only has high single-pass yield and high selectivity, but also has shorter reaction time; is easy to realize continuous reaction in gas phase independent circulation, and has the characteristics of high synthesis efficiency. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: Fluorination catalysts for preparation of hydrofluoroolefins from hydrochlorofluorocarbons, comprising obtained by fluorination catalyst precursor, where precursor of the fluorination catalyst is composed of trivalent chromium compound and tungstate, the mass ratio of trivalent chromium compound and tungstate is 70-99%:1-30%, catalyst obtains by mixing trivalent chromium compound and the tungstate uniformly according to the mass ratio, and pressing into shape to obtain fluorination catalyst precursor, then drying fluorination catalyst precursor, calcining and activating to obtain the fluorination catalyst; and Preparing hydrofluoroolefins by gas-phase continuous reaction, comprising hydrochlorofluorocarbons of formula (R-CHClCHCCl(R)CF) (I) and hydrogen fluoride under the catalyst, performing gas-phase fluorine-chlorine exchange reaction to obtain hydrofluoroalkene of formula (R-CH=CH-CF(R)CF)(II).h12h23f1f23 Rh1= chlorine atom, fluorine atom, trifluoromethyl group or trichloromethyl group; Rh2= chlorine atom or trifluoromethyl group; and Rf1and Rf2= fluorine atoms or trifluoromethyl groups.