Oxygen reduction on platinum electrode coated with Nafion®

Negative resistance for methanol electro-oxidation on platinum/carbon (Pt/C) catalyst investigated by an electrochemical impedance spectroscopy

“…The CV curve in Fig. 1a is inconsistent with classical studies [18,19]. During the positive scan, two peaks relating to the hydrogen oxidation on Pt (110) and (111) facets are exhibited in the range of À0.25 V to 0.2 V (vs. SCE) [20].…”

Influence of Nafion® film on oxygen reduction reaction and hydrogen peroxide formation on Pt electrode for proton exchange membrane fuel cell

“…A lot of studies about ORR on Nafion ® -coated Pt electrodes have been conducted so far [28][29][30][31][32]. Gottesfeld et al [33], Lawson et al [34], and Floriano et al [35] concluded that the kinetic currents for ORR on Nafion ® -coated Pt electrodes were larger than those on bare Pt electrodes in aqueous solutions.…”

Application of Butler–Volmer equations in the modelling of activation polarization for PEM fuel cells

“…Such a 'rough' or 'porous' electrode surface could perhaps be expected to have an 'r' value in the range 1 < r < 10. For example, Ayad et al [33] reported roughness factors on smooth Pt of ∼3 while Ho and Piron [34], in their study of surface area determination of Pt in KOH, summarized roughness factors for 'bright Pt wire' determined by three different methods, in both 5 M KOH and 0.5 M H 2 SO 4 , and showing good agreement, 'r' values ranging from 1.7 ± 0.0 to 1.8 ± 0.1. Mitsushima et al [35], from their work with a Pt disk microelectrode on Nafion, reported roughness factors from 1.5 to 1.8.…”

“…In a 'real' fuel cell MEA, the ratio of the actual active Pt area to the 'plane' cell area, r MEA , could probably range from several 'tens' to several hundred. For example, Ayad et al [33] reported A act /A geo for Pt/Nafion PEM electrodes of ∼160. (These values were determined by hydrogen ads/des voltametry which also revealed that these ratios were greater for the HOR on the anode than for the ORR on the cathode.)…”