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Enhanced Activity for Methanol Oxidation of Platinum Particles Supported on Iridium Oxide Modified Boron‐Doped Diamond Powder
Author(s) -
Preda Loredana,
Kondo Takeshi,
Spataru Tanta,
Marin Mariana,
Radu Mihai,
Osiceanu Petre,
Fujishima Akira,
Spataru Nicolae
Publication year - 2017
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201700155
Subject(s) - iridium , platinum , methanol , inorganic chemistry , chemistry , diamond , oxide , tafel equation , electrocatalyst , cyclic voltammetry , x ray photoelectron spectroscopy , platinum nanoparticles , electrochemistry , catalysis , electrode , chemical engineering , organic chemistry , engineering
Electrocatalytic activity toward methanol oxidation in alkaline media of platinum nanoparticles supported on iridium oxide modified boron‐doped diamond powder (Pt/IrO 2 /BDDP) was assessed, and was compared with that of Pt deposited on bare diamond particles (Pt/BDDP). Cyclic voltammetry attests that the presence of the iridium oxide intermediary layer promotes methanol oxidation and provides a more efficient reactivation of Pt particles. Linear sweep voltammetric experiments performed in methanol‐free solution indicated that, at Pt/IrO 2 /BDDP, oxygen evolution is preceded by the formation, within the potential range of CH 3 OH oxidation, of adsorbed oxygenated species. As expected, the presence in close proximity of Pt particles of such species and of an important amount of IrO x (OH) y (evidenced by XPS) assists in the oxidative desorption of CO species adsorbed on Pt active sites. Steady‐state polarization measurements carried out in a floating configuration with Pt/IrO 2 /BDDP gas‐diffusion‐type electrodes yielded for methanol oxidation overall process Tafel slope values of ca. 120 mV decade −1 , which compare well with those reported for traditional electrocatalysts.