Electrochemical oxidation of carbon monoxide: From platinum single crystals to low temperature fuel cells catalysts, Part I: Carbon monoxide oxidation onto low index platinum single crystals

Abstract

The electrochemical oxidation of carbon monoxide and the interfacial structure of the CO adlayer (COads) on platinum low index single crystals, Pt(111), Pt(100) and two reconstruction of Pt(110), were examined using the rotation disk electrode method in combination with the in situ surface X-ray diffraction scattering technique. The mechanism of CO oxidation is discussed on the basis of the findings that, depending on the potential, two energetic states of COads exist on the platinum surfaces. Thus, at lower potentials, weakly bonded states (COads,w) and at higher potentials strongly bonded states (COads,s) are formed. The mechanism of the oxidation of hydrogen-carbon monoxide mixtures is also proposed.

Korišćenjem tehnike rotirajuće disk elektrode i in-situ tehnike površinske difrakcije X-zraka, ispitivana je reakcija elektrohemijske oksidacije ugljen-monoksida i priroda adsorbovanog CO na monokristalima platine niskih indeksa orijentacije, Pt(111), Pt(100) i dve rekonstrukcije Pt(110). Diskutovan je mehanizam oksidacije CO na osnovu ustanovljenog postojanja dva energetska stanja adsorbovanog ugljen-monoksida, slabo vezanog stanja pri nižim potencijalima i čvrsto vezanog stanja pri višim potencijalima. Takođe je diskutovan mehanizam oksidacije smeša vodonika sa ugljen-monoksidom.