X-ray photoelectron spectroscopy and electrochemical studies of ruthenium electrodeposition at 6-mercaptohexanol modified platinum electrodes

Ruthenium electrodeposition on a self-assembled monolayer on Pt electrodes has been studied by X-ray photoelectron spectroscopy. A self-assembled monolayer route to disperse Ru on Pt electrodes has been explored. The Pt substrates were immersed for 1 min in a 1 mM 6-mercaptohexanol (6-MCH) solution prior to the Ru electrodeposition. This was done in a freshly prepared solution of 5 mM RuCl3 in 0.5 M H2SO4. An applied potential of 100 mV vs. Ag/AgCl and a charge of 0.2 mC was used. Then, electrochemical desorption of the organic molecules was done in 0.1 M KOH at an applied potential of −1.6 V vs. Ag/AgCl. The modified and unmodified surface structures were examined by X-ray photoelectron spectroscopy and electrochemical techniques. The Pt/Ru catalyst electrodes were used in methanol oxidation measurements. They were compared to bare Pt electrodes.