Pd-P nanoparticles as active catalyst for the hydrogenation of acetylenic compounds

Pd-P nanoparticles were obtained by low-temperature reduction of Pd(acac)2 with hydrogen in the presence of elemental phosphorus. Using the EDX analysis, XRD, and HRTEM, the composition, size, and morphology of the particles were determined for different P:Pd ratios. The results of testing Pd-P nanoparticles showed that they are 8–9 times higher in activity in the hydrogenation of mono- and di-substituted acetylenic compounds than Pd-black and phase-pure Pd3P phosphide, while maintaining high selectivity to alkenes at 95–98% conversion of alkynes. Colloidal solutions of Pd-P nanoparticles can act as long-lived supported catalysts (TON = 27,444 mol PA·(mol Pd total)−1). The effect of the P:Pd ratio on the change in the rates of hydrogenation of alkyne (r1) and the resulting alkene (r2) under the action of Pd-P nanoparticles has been found and experimentally substantiated. Electron-deficient small clusters of palladium contained along with palladium phosphides in the Pd-P nanoparticles are responsible for the decrease in the ratio r1:r2 in the ratio range P:Pd = 1–1.5.