Synthesis and catalytic properties of alkanethiolate-capped Pd nanoparticles generated from sodium S-dodecylthiosulfate

This article presents a synthetic method for alkanethiolate-functionalized Pd nanoparticles that are efficient catalysts for the isomerization of allyl alcohol to propanal. Pd nanoparticles are produced by the borohydride reduction of K2PdCl4 in toluene/H2O using sodium S-dodecylthiosulfate as a source for the stabilizing ligands. The nanoparticles are characterized by H-1 NMR, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), UV-vis absorption spectroscopy, and thermogravimetric analysis (TGA). These analyses suggest that the monolayer capped Pd nanoparticles from sodium S-dodecylthiosulfate are quite comparable in composition (dodecylthiolate) and core size from those previously prepared from dodecanethiol. However, the catalytic activity of Pd nanoparticles generated from S-dodecylthiosulfate is found to be much greater than that of Pd nanoparticles prepared from dodecanethiol. The increased catalytic activity of Pd nanoparticles is likely to be due to the lower ligand density (organic weight fraction) of Pd nanoparticles generated from S-dodecylthiosulfate. The catalytic activity of PdAu nanoparticles on the isomerization of allyl alcohol is also demonstrated.