Hydrogen peroxide and oxygen reduction studies on Pt stepped surfaces: Surface charge effects and mechanistic consequences

Abstract

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Mixed Diffusion‐Kinetic Control of H2O2 Oxidation at an Oxide‐Covered Platinum Electrode in Alkaline Electrolyte: Implications for Oxygen Electroreduction Studies with a Rotating Ring Disk Electrode

“…Diffusion‐controlled H 2 O 2 oxidation at bare Pt ring electrode is also confirmed by the agreement in the magnitude of anodic (H 2 O 2 oxidation) and cathodic (H 2 O 2 reduction) currents in Figure S3. Besides, the recorded current value of 0.647 mA for bare platinum ring electrode is consistent with previous H 2 O 2 oxidation experiments at polycrystalline [14] and single crystal [15] platinum electrodes (details in Supporting Information).…”

“…Herein, we demonstrate that deviation from pure diffusion control of H 2 O 2 oxidation in the alkaline electrolyte is observed only when the platinum electrode is covered with a surface oxide layer. We confirm that bare platinum ring provides diffusion‐controlled H 2 O 2 oxidation, as it has been pointed out before for both polycrystalline [14] and single crystal [15] platinum electrodes. Unfortunately, during the ORR studies H 2 O 2 oxidation at Pt ring occurs in parallel with platinum surface oxide formation [16] .…”

Design Engineering, Synthesis Protocols, and Energy Applications of MOF-Derived Electrocatalysts

“…Besides the design of structures and morphologies, how to control them is still an additional critical key in constructing high-efficiency catalysts derived from MOFs, as it directly links with exposed facets and active sites. The activity of each facet differs extensively because of their diverse electronic structures, as it is shown through the ORR catalytic performance for the Pt low index surfaces diminishes by the following direction: (110) > (111) > (100) [ 74 , 75 ]. Therefore, controlling the objective morphological structure is a significant approach for rising the inherent activity throughout exposing active facets in addition to sites.…”

Structure effects on electrocatalysts. Oxygen reduction on Te-modified Pt(111) surfaces: Site-blocking vs electronic effects

“…54 A gradual diminution in j lim during the ORR, without an increase in H 2 O 2 formation, has also been found in clean surfaces as the pH of the solution is increased, and it has been attributed to a kinetic effect on the reduction of OOH * . 52,55 It is expected that, since the reduction of this species would require the addition of a proton, its kinetics would be affected by the structure of water close to the surface and more difficult to achieve in neutral pH values, relative to acid solutions. 52,55 This topic will be discussed in more detail in a forthcoming paper.…”

“…52,55 It is expected that, since the reduction of this species would require the addition of a proton, its kinetics would be affected by the structure of water close to the surface and more difficult to achieve in neutral pH values, relative to acid solutions. 52,55 This topic will be discussed in more detail in a forthcoming paper.…”