Agglomeration and Cleaning of Carbon Supported Palladium Nanoparticles in Electrochemical Environment

作者：Martins Caue A^*; Fernandez Pablo S; Troiani Horacio E; Martins Maria E; Arenillas Ana; Camara Giuseppe A

来源：Electrocatalysis, 2014, 5(2): 204-212.

DOI：10.1007/s12678-014-0184-3

• Palladium nanoparticles
• PVP
• Cleaning process
• Agglomeration of nanoparticles
• Active surface area
• CO probe

Here we investigate the electrochemical behavior of Pd/C synthesized by reduction with ethylene glycol in the presence of polyvinylpyrrolidone (EG-PVP). EG-PVP produces nanoparticles (NPs) with a narrow size distribution, but some of them remain covered by impurities after the synthesis. After successive voltammetric cycles, NPs become cleaner, but some agglomeration and structural modification occur; these effects affect the electrochemical behavior of Pd/C in different ways, so we used CO as a probe to better understand the processes taking place. CO stripping shows that the general features of the multiple oxidation peaks change with the number of cycles. Possibly, CO and OH from different NPs react when the particles agglomerate, contributing to CO stripping changes. Finally, different active areas are found when the charges involved in CO oxidation and PdO reduction are compared. Such differences are rationalized in terms of a balance between the increase of sites which promote the oxidation of CO and the loss of area provoked by the growing of the particles.

• 出版日期2014-4