Ternary metal catalyst for synthesizing low-carbon carboxylic acid alkenyl ester as well as preparation method and application of ternary metal catalyst

The invention provides a ternary metal catalyst for synthesizing low-carbon carboxylic acid alkenyl ester and a preparation method and application thereof, the ternary metal catalyst comprises an active component, a carrier, an auxiliary active component and a modified component, the active component comprises metal Pd, Cu and Zn; the preparation method comprises the following steps: (a) impregnating the carrier in a mixed impregnation liquid containing salts of Pd, Cu and Zn and a modified metal compound to obtain a catalyst precursor I; (b) converting salt containing Pd, Cu and Zn into a precipitation type from a solution type by using an alkaline solution to obtain a catalyst precursor II; (c) washing the catalyst precursor II in the step (b) to be neutral; (d) reducing the combined Pd, Cu, Zn and the modified metal in the precipitation form into a metal state to obtain a catalyst precursor III; (e) dipping in an auxiliary active component solution; and (f) drying to obtain the catalyst. The ternary metal