Decoration of Ni/C with Small Amounts of Pd and Au for Allyl Alcohol Oxidation

The decoration of the surface of Ni nanoparticles supported on carbon black with Pd and Au and the electrooxidation of allyl alcohol on the Au/Pd/Ni/C catalysts in alkaline solution have been investigated. The decoration of Ni/C is performed by the electrochemical deposition of a small amount of Pd and then Au on Ni/C, and the Au-x/Pd-y/Ni-100/C catalysts with the (x+y):100 atomic ratios of less then 4.5 (0.2 y < 3.1) are prepared. Characterizations of Au/Pd/Ni/C reveal a uniform dispersion of the metal nanoparticles on carbon black and a low coverage of Au and Pd on the Ni nanoparticle surface. Au/Pd/Ni/C behaves more similar to Pd/C than Au/C in allyl alcohol oxidation, and the catalytic activity of Au/Pd/Ni/C depends on the amounts of Pd and Au, with Au-0.9/Pd-2.2/Ni-100/C exhibiting the highest activity. Besides Pd and Au, the Ni nanoparticles also play important roles in the activity of Au/Pd/Ni/C, although Ni itself has no catalytic activity. The lack of any one of Pd, Au and Ni leads to low catalytic activity, indicating the synergy among the three metals. The result is helpful for preparing ternary electrocatalysts by the surface decoration.