Preparation method for ultralow-mercury catalyst for vinyl chloride synthesis

A provided preparation method for an ultralow-mercury catalyst for vinyl chloride synthesis comprises preparation of active carbon and adsorption, and the adsorption step comprises a gas phase adsorbs mercuric chloride and a liquid phase adsorbs a synergic promoter. The prepared ultralow-mercury catalyst comprises, in percent by weight, 0.93-1.0% of mercuric chloride, 2.4-2.5% of zinc chloride, 1.2-2.5% of barium chloride, 1.2-3.75% of tetrabutyl ammonium chloride, 1.25-2.4% of tetraamminepalladium dichloride, and 0.2% of water. The catalyst possesses the mechanical strength of 96.6-96.9%, the granularity of 3-6 mm (97-97.5%) and the bulk density of 500-505 g/L. The prepared ultralow-mercury catalyst is applied to vinyl chloride synthesis reaction, the acetylene conversion rate is 99.90-99.91%, the vinyl chloride selectivity is 99.9-100%, and the vinyl chloride yield is 94.2-94.5%.