Synthesis of dicyandiamide modified palladium nano-catalyst and application of dicyandiamide modified palladium nano-catalyst in catalyzing semi-hydrogenation of phenylacetylene

The invention provides synthesis of a dicyandiamide modified palladium nano-catalyst and application of the dicyandiamide modified palladium nano-catalyst in catalyzing semi-hydrogenation of phenylacetylene. The synthesis comprises the following steps: firstly, dissolving polyvinylpyrrolidone, sodium formate and a sodium tetrachloropalladate solution into a thick-wall pressure-resistant bottle containing N, N-dimethylformamide or formamide together, then putting the thick-wall pressure-resistant bottle into an oil bath pan, reducing palladium through high temperature, then centrifugally separating out palladium nanoparticles, and dissolving to form a palladium nanoparticle solution; mixing the palladium nanoparticle solution with dicyandiamide and N, N-dimethylformamide, putting the mixture into the oil bath pan, keeping the temperature for a certain time at a high temperature to obtain a dicyandiamide-modified palladium nanoparticle solution, centrifugally separating out dicyandiamide-modified palladium nano