▎ 摘　　要

NOVELTY - Initiator claimed. The initiator is obtained by initiator precursor, and the initiator precursor is composed of iron element and carrier in a mass ratio of 5-30%:70-95%; the carrier is activated carbon, molecular sieve, silicon dioxide, silicon carbide, graphite and/or graphene; and the initiator is prepared by immersing soluble salt of iron element on carrier, and filtering to obtain initiator precursor, drying obtained initiator precursor, calcining and activating to obtain initiator. USE - The initiator useful for preparation of hydro-chlorofluorocarbon by halogenated alkenes and halogenated alkanes to prepare fluorination catalyst for hydro-fluoroolefin (all claimed). ADVANTAGE - The preparation method of perfluoro-3-methyl-2-butanone: utilizes simple and easily available raw materials; has high conversion rate, high selectivity and easy reaction control condition; and is suitable for industrial production. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: 1. fluorination catalyst for preparation of hydro-fluoroolefin from hydro-chlorofluorocarbon, comprising preparing fluorination catalyst by fluorination catalyst precursor, where the fluorination catalyst precursor composed of trivalent chromium compound and tungstate in a mass ratio of 70-99%:1-30%, and catalyst obtained by uniformly mixing trivalent chromium compound and tungstate, pressing and forming to obtain fluorination catalyst precursor, drying obtained catalyst precursor, calcining and activating to obtain fluorination catalyst; and 2. preparing perfluoro-3-methyl-2-butanone, comprising subjecting 2-fluoro-2,3,3-tris(trifluoromethyl)oxirane to isomerization reaction in presence of isomerization catalyst under gas phase condition to obtain perfluoro-3-methyl-2-butanone.