Pd Size Effect in Liquid Phase Semihydrogenation of Substituted Alkynes on Supported Pd Catalysts
Alkynes are versatile reagents in organic synthesis since C≡C group can be easily
transformed to a cis-alkene through stereoselective addition of hydrogen molecule on Pd
catalyst. This so called semihydrogenation is often an important step in industrial processes as
well as in laboratory-scale reactions. However, careful selectivity control and minimization of
over-hydrogenation is required. In this work we studied a relationship between the size of Pd nanoparticles (ranging from 1.5 to 22 nm) in 1%Pd/Al2O3 catalyst and the activity/selectivity in liquid-phase
diphenylacetylene (DPA) hydrogenation.