Electrochemical Activity of Carbon-Supported Pt-Nanoparticles: Effect of Pt-Precursor Ligand and/or Presence of Anions During Polyol Synthesis

This study revisits the impacts of the presence of OH⁻ and Cl⁻ anions and/or different forms of Pt precursors during polyol synthesis of carbon-supported electrocatalysts. Efficiency of the synthesis process in terms of the %conversion of a Pt complex to Pt metal has been quantified. It is observed that Pt precursors based on [PtCl₆]²⁻ are reduced easily compared to those based on [Pt(OH)₆]²⁻. Furthermore, presence of excess Cl⁻ during synthesis results in decreased %conversion and reduced ECSA, which is opposite from other reported work synthesized at higher temperature and pure solvents. For Pt/C synthesis under mild conditions, 100 °C and 30 vol% EG in water as solvent, presence of OH⁻ during synthesis decreases the ECSA and hence increases the Pt nanoparticle size and change of catalyst surface structure. Finally, a method to get insights into the surface structure of Pt-nanoparticles through analysis of the H-adsorption/H-desorption peaks has been proposed. Graphical Abstract: [Figure not available: see fulltext.].