METHOD FOR PREPARING 1, 1-DIFLUOROETHYLENE

A method for preparing 1, 1-difluoroethylene, comprising the following steps : i) preparing an inorganic alkali alcohol saturated solution; and ii) placing the inorganic alkali alcohol saturated solution and a fluorinated rare earth catalyst into a reaction vessel provided with a condensing reflux device and a gas collection conduit, introducing 1, 1-difluoro-1-chloroethane, and collecting the vinylidene fluoride product from the gas collection conduit. The fluorinated rare earth catalyst comprises an active ingredient and an auxiliary ingredient, wherein the active ingredient comprises a fluorinated rare earth, an acetoacetonate, and ferric chloride; and the auxiliary ingredient comprises a C1-6 alkylamine, a C1-6 alkyl alcohol salt, a C1-6 alkyl alkanolamine, an alkali metal hydride, or a mixture thereof.