Royal Society of Chemistry, New Journal of Chemistry, 7(38), p. 2865-2873, 2014
DOI: 10.1039/c4nj00041b
Full text: Download
In this study we report a friendly route to produce colloidal AuAg bimetallic nanoparticles (NPs) using glycerol as reducing chemical in alkaline medium. Ultraviolet spectroscopy (UV-Vis) and transmission electron microscopy (TEM) confirmed the formation of colloidal NPs. The nanoparticles were also directly produced onto carbon to yield Au/C, Ag/C and AuAg/C. Extended X-ray absorption fine-structure (EXAFS) spectroscopy at the Au L3 edge evidenced surface segregation of silver in the AuAg/C material. Also the X-ray absorption near edge structure (XANES) region indicated a slight reduction in the Au 5d band occupancy due the presence of silver. Since Fuel Cell is a potent source of energy for the future, the catalytic properties of the NPs were then investigated for anodic glycerol electro-oxidation reaction and results for AuAg NPs are compared with those for monometallic Au and Ag NPs. When compared with Au/C, the AuAg/C material displayed lower potential for glycerol electro-oxidation, reducing by 120 mV the onset potential for glycerol electro-oxidation. This means that the electro-oxidation of glycerol at the bimetallic catalyst is mainly affected by the ligand effect.