Redox catalysts based on Au and Pd/PdO bimetallic nanoparticles confined in mesoporous silica SBA-15

B.F. Dias, E. Teixeira-Neto, A.A. Teixeira-Neto
Universidade Federal do ABC, BR

Keywords: gold nanoparticles, palladium nanoparticles, oxidation catalysts

Summary:

Since the catalytic activity of nanoscale gold was discovered many studies in this subject have been done. A very interesting system, based on Au and Pd bimetallic nanoparticles (NPs), has emerged from those studies, and it was discovered that there is a synergistic effect between both metals, since Pd is able to promote, for certain reactions, the activity of Au, and vice versa. In this work, Au-Pd/PdO NPs with varying molar ratios were supported on mesoporous molecular sieve SBA-15. X-ray Diffraction results indicate the presence of Au-Pd alloy in all bimetallic samples. In Pd-rich samples the presence of PdO is evident from the diffractograms. Transmission Electronic Microscopy images show the ordered structure of the mesoporous sieve and the formation of small bimetallic NPs confined in its channels. For Pd-rich samples it is also possible to observe PdO NPs conjugated with the alloy NPs. The investigation described in this work, on the morphology and the composition of bimetallic Au-Pd nanoparticles confined in SBA-15 channels, is crucial for understanding the catalytic activity of these materials in redox reactions such as alcohol oxidations.