Accession Number:

ADA027525

Title:

Mechanisms of Electrochemical Reactions on Non-Metallic Surfaces.

Descriptive Note:

Technical rept.,

Corporate Author:

CASE WESTERN RESERVE UNIV CLEVELAND OHIO ELECTROCHEMISTRY RESEARCH LAB

Personal Author(s):

• Yeager,Ernest

Report Date:

1976-02-01

Pagination or Media Count:

28.0

Abstract:

Oxygen electrocatalysis has assumed new importance because of the involvement of the O2 electrode in various fuel cells and electrolyzer systems. For O2 electroreduction to proceed at reasonable current densities requires the adsorption of the O2 molecule or ion on the electrode surface. Various models for the interaction of such O2 species with surfaces and the corresponding pathways for the electro-reduction are considered. Generally peroxide mechanisms are predominant in aqueous solutions on non-metallic as well as metal surfaces but this leads to less favorable operating potentials for O2 cathodes. A number of reasonably effective O2 electroreduction catalysts have been identified for alkaline solutions but so far only high area platinum appears to combine reasonable activity and stability in acid electrolytes. Various electrocatalysts for which results have been reported in the literature are summarized. The electrochemical behavior of various carbons and graphites, lithiated NiO and various defect metal oxides including RuO2Ti is considered in some detail relative to O2 generation as well as reduction kinetics.

Descriptors:

• *SEMICONDUCTOR DEVICES
• *OXYGEN
• *ELECTRODES
• *SURFACE CHEMISTRY
• ELECTROCHEMISTRY
• GRAPHITE
• CARBON
• OXIDES
• CHEMICAL REACTIONS
• CATALYSTS
• ELECTROLYTES
• FUEL CELLS
• NICKEL COMPOUNDS

Subject Categories:

• Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE