▎ 摘　　要

NOVELTY - Initiator, which is obtained through initiator precursor, is claimed. The initiator precursor comprises 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. The initiator is prepared by the following method soaking the soluble salt of the iron element on the carrier according to the mass percentage composition of the iron element and the carrier, filtering to obtain the initiator precursor, then drying the initiator precursor, calcining and activating to obtain the initiator. USE - The initiator is used for preparing hydrochlorofluorocarbons by halogenated olefins and halogenated alkanes (claimed). DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: fluorination catalyst for preparation of hydrofluoroolefins by hydrochlorofluorocarbons obtained by fluorination catalyst precursor comprising trivalent chromium compound and tungstate in a mass ratio of (70-99%):(1-30%), the catalyst is obtained by the following preparation method: uniformly mixing the trivalent chromium compound and tungstate, pressing into shape to obtain a fluorination catalyst precursor, then drying the fluorination catalyst precursor, calcining and activating to obtain the fluorination catalyst; and preparing E-1,1,1,4,4,4-hexafluoro-2-butene and Z-1,1,1,4,4,4-hexafluoro-2-butene, comprising reacting halogenated hydrocarbons and hydrogen fluoride in the presence of a fluorination catalyst to generate fluorine-containing olefins, where the fluorine-containing olefin reacts with the haloalkane to generate hydrochlorofluorocarbons in the presence of an initiator, the hydrochlorofluorocarbon reacts with hydrogen fluoride in the presence of a fluorination catalyst to generate E-1,1,1,4,4,4-hexafluoro-2-butene and Z-1,1,1,4,4,4-hexafluoro-2-butene.