Highly selective catalysts for liquid-phase hydrogenation of substituted alkynes based on Pd-Cu bimetallic nanoparticles

Catalytic properties of Pd-Cu bimetallic catalysts supported on SiO2 and Al2O3 were studied in a model reaction of selective hydrogenation of diphenylacetylene. Application of PdCu2(AcO)(6) heterobimetallic acetate complex as a precursor made it possible to obtain homogeneous Pd-Cu bimetallic nanoparticles. This result was supported by the data of IR spectroscopy of adsorbed CO. The Pd-Cu catalysts showed considerably higher selectivity than monometallic samples. Moreover, the introduction of copper decreases the hydrogenation rate of diphenylethylene (DPE) to diphenylethane. As a result, the maximum yield of the target product, DPE, increased from 78 to 93% in the presence of Pd-Cu catalysts.