Abstract
Pt, 50Pt-50RuO2 and 50Pt-50IrO2 electrodes were prepared on titanium (Ti) substrate by thermal decomposition techniques. The micrographs of 50Pt-50RuO2 and 50Pt-50IrO2 have revealed that their surfaces are rough with cracked structures. That of platinum was smooth, compact and homogeneous. The richer the electrode ‘surface in platinum, thinner is the crack size and also more compact is the electrode’surface. The electrodes have also been characterized electrochemically by cyclic voltammetry in acid (HClO4) and in alkaline (KOH) electrolytes. These characterizations showed that the surface of the 50Pt-50RuO2 and 50Pt-50IrO2 electrodes were composed by platinum and metal dioxide active sites. The Tafel slope obtained on Pt, 50Pt-50RuO2 and 50Pt-50IrO2 for the oxygen evolution reaction (OER) were respectively 120, 90 and 44 mV/dec in acid electrolyte. In the alkaline electrolyte, they were 119, 87 and 42 mV/dec respectively on Pt, 50Pt-50RuO2 and 50Pt-50IrO2 electrodes indicating that for the prepared electrodes, Tafel slopes are the same in acid and in alkaline media. Moreover, in acid and in alkaline media, the kinetic of the oxygen evolution reaction was rapid on 50Pt-50RuO2 and 50Pt-50IrO2 than Pt owing to a synergetic effect of Pt and the oxides. That additional effect of the surface component 50Pt-50RuO2 and 50Pt-50IrO2 electrodes let them possess high electrocatalytic activity towards OER than Pt in the two media. Though the kinetic of the oxygen evolution reaction is practically the same in acidic and alkaline media for all the electrodes, OER occurred at lower overpotential in alkaline electrolyte than in acidic electrolyte on the prepared electrodes.
Highlights
Oxygen evolution reaction (OER) has been extensively studied in electrochemistry because of its importance in many fields such as fuel cells, wastewater treatment, chlorine evolution, corrosion, water electrolysis [1,2,3,4,5,6,7]
The surface of 50Pt-50RuO2 (Figure 1b) is rough and seems to be compact as that of platinum but cracks were observed like those of Dimensionnally stable anodes (DSAs)’s [16,17]. Such finding indicated that the electrode surface of the 50Pt-50RuO2 electrode is composed by platinum and ruthenium dioxide
The size of the cracks are thinner as generally observed at such magnification for pure DSAs possibly due to the presence of platinum which contributes to render the combined electrode surface to have compact structures. doi:10.5599/jese
Summary
Oxygen evolution reaction (OER) has been extensively studied in electrochemistry because of its importance in many fields such as fuel cells, wastewater treatment, chlorine evolution, corrosion, water electrolysis [1,2,3,4,5,6,7]. Used for the oxidation of organics such as methanol and ethanol, platinum undergoes electrode fouling reducing its electrooxidation activities. Since it is known that OER depends mainly on chemical and structural properties of electrode materials surface, our interest was focused on platinum and transition metal oxide modified platinum electrodes. The aim of the present study was to investigate the electrocatalytic activity and the kinetics of the OER on the same kind of electrode i.e. platinum modified with various transition metal oxides
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
