Oxygen reduction reaction, scanning

Fig. 12.5 (a) Illustration of charge transfer process and oxygen reduction reaction on PDDA-CNT (b) LSV curves of ORR in an 02-saturated 0.1 MKOH solution at a scan rate of 10 mV s . The rotation rate is 1,600 rpm (reproduced with permission [51])... 

Fig. 15.6 RRDE measurements of oxygen reduction reactions on four Ag/C catalysts with different metal loadings, Vulcan XC-72, and 20 wt.% Pt/C (BASF) with a rotation rate of2,500rpm in oxygen-purged 0.1 M NaOH. Collection efficiency N = 0.23 ring potential , = 0.3 V versus Hg/HgO scan rate 20 mV s [37]...

Fig. 18.9 Cyclic voltairanograms corresponding to the oxygen reduction reaction using a glassy carbon in a N2 (dotted line) and 02-saturated (solid line) [P666i4][Cl] in the presence of 1.5 wt% of water (a) scanned up to —1 V and (b) scanned up to —1.9 V. Scan rate 10 mV s ...

Sanchez-Sanchez CM, Bard AJ (2009) Hydrogen peroxide production in the oxygen reduction reaction at different electrocatalysts as quantified by scanning electrochemical microscopy. Anal Chem 81(19) 8094—8100... 

Figure 15.17. ORR polarization curves for W-Co-Se and Pt/C in 0.5 M H2SO4 at 25 C. Potential scan rate 5 mV/s. Pt/C loading is 122 pg/cm [HO]. (Reprinted from Electrochemistry Communications, 9(7), Lee Kunehan, Zhang Lei and Zhang Jiujun, Ternary non-nohle metal chalcogenide (W-Co-Se) as eleetrocatalyst for oxygen reduction reaction, 1704—8, 2007, with permission from Elsevier.)...

Lin, C.-L., Sanchez-Sanchez, C.M., Bard, A.J. Methanol tolerance of Pd-Co oxygen reduction reaction electrocatalysts using scanning electrochemical microscopy. Electrochem. Solid State Lett. 2008, 11, B136-B139. 

The rate of oxygen reduction on the oxide-free Pt surface is limited by the mass transport of dissolved oxygen to the electrode surface. The dependence of the oxygen reduction on the scan rate, v, was examined. Figure 31 shows the linear potential sweep voltammetric i-E curves for a Pt/diamond composite electrode in 02-saturated 0.1 M HCIO4 [125]. The peak current, ip, increases linearly with when the scan rate is varied from 50 to 400 v/s, indicative of a semi-infinite linear diffusion-controlled process. However, ip rather approaches a proportionality with v at scan rates higher than 400 v/s. This is expected as the reaction shifts from being mass transport limited to control by the surface adsorption process. 

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