Recent advances in the kinetics of oxygen reduction

Abstract

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or proctss disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise dots not necessarily constitute or imply its endorsement, mommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. 11 Reaction Pathways and MechanismsReaction pathways, rather than reaction mechanisms, were often analyzed since in many cases, particularly for a four-electron O2 reduction, formulation of the latter proved too complex. These analyses are based on the data obtained by a rotating disk-ring technique which enables the quantitative determination of some of the reaction intermediates. Since the first proposition by Damjanovic et al. (42), there were several reaction schemes proposed for analyzing the diskring data and calculating the rates of various reaction steps (43, 44, 45). The merits of various schemes were considered by Hsueh et al. (46) and Tarasevich et .al. (1). The formulation of the

A new spectroelectrochemical cell for in situ measurement of Pt and Au K-edge X-ray absorption fine structure

“…The structure and reaction mechanism of platinum (Pt) electrocatalysts in the ORR have been studied to reveal ORR catalysis on an atomic level. [1][2][3][4][5] In recent years, core-shell electrocatalysts have drawn wide attention to improve the mass-specific activity of Pt. 6 A typical effective core-shell electrocatalyst is a gold (Au) core with a Pt shell.…”

Density Functional Theory Study of Transitional Metal Macrocyclic Complexes' Dioxygen-Binding Abilities and Their Catalytic Activities toward Oxygen Reduction Reaction

“…The activity should be associated with dioxygen binding, and the heat of O 2 adsorption on the metal center appears to be the origin of the correlation of the activity for O 2 reduction with the redox potential. 11 Theoretical studies of dioxygen binding of heme and some metalloporphyrins (MP, M ) Fe, Co, Mn, Ni) have been reported in the literature. [12][13][14][15][16][17] However, systematic investigation of dioxygen binding for cobalt, iron phthalocyanine, and porphyrin derivatives is not available.…”

Theoretical Study of Possible Active Site Structures in Cobalt- Polypyrrole Catalysts for Oxygen Reduction Reaction

“…The latter process may be followed by several electrochemical and/or chemical steps, eventually resulting in an indirect 4e reduction of oxygen to water. 62 In this work, we adopted Yeager's concept and used oxygen adsorption configuration as a base for deducing the reaction pathway, i.e., the side-on adsorption indicating a 4e pathway and the end-on adsorption attesting to either 2e or 4e pathways. On the basis of our current knowledge of Co-catalyzed oxygen reduction reaction, we further postulate that the end-on adsorption on Co leads to 2e products.…”