Selective Hydrogenation of Phenylacetylene Using Block Copolymer Additional Poisoning Agent

A block copolymer, poly (styrenc-block-4-vinylpyridine) is used as an additional poisoning agent in combination with Lindlar's catalyst to drastically afreet the selectivity in the semi-hydrogenation of phenylacetylene. Selectivity is demonstrated from gas chromatography data. The extra advantage in terms of preparing poisoning agent free, very pure and dry monomer are illustrated.