Effect of temperature on electrode kinetic parameters for hydrogen and oxygen evolution reactions on nickel electrodes in alkaline solutions

Journal Article · Mon Mar 01 04:00:00 EST 1976 · J. Electrochem. Soc.; (United States)

DOI:https://doi.org/10.1149/1.2132820· OSTI ID:7363826

Miles, M H; Kissel, G; Lu, P W.T.; Srinivasan, S

The electrode kinetic parameters for hydrogen and oxygen evolution were determined at temperatures of 80, 150, 208, and 264/sup 0/C on nickel electrodes in 50 percent KOH solutions. Improvements in the exchange current density with increasing temperature were more significant for the oxygen evolution reaction than for the hydrogen evolution reaction. A favorable change in the Tafel slope for the oxygen evolution reaction occurs between 150 and 264/sup 0/C which corresponds to an increase in the transfer coefficient from 0.67 to 3.3. This result supports the concept that a change in the reaction mechanism occurs for the oxygen electrode reaction near the Neel temperature of nickel oxide. At the higher experimental temperatures, the Tafel slope for the hydrogen evolution reaction changes from 2RT/3F at low overpotentials to about 2RT/F at high overpotentials suggesting a slow electrochemical desorption mechanism. The present study indicates that significant reductions in cell voltage for water electrolysis can be obtained by higher operating temperatures. At temperatures of about 150/sup 0/C, it should be possible to approach a 100 percent energy efficiency (based on ..delta..H) at current densities commonly used in commercial water electrolyzers. (auth)

• Research Organization: Brookhaven National Lab., Upton, NY
• OSTI ID: 7363826
• Journal Information: J. Electrochem. Soc.; (United States), Journal Name: J. Electrochem. Soc.; (United States) Vol. 123:3; ISSN JESOA
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
080101* -- Hydrogen-- Production-- Electrolysis
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
AQUEOUS SOLUTIONS
CHEMICAL REACTION KINETICS
CRYOGENIC FLUIDS
DISPERSIONS
EFFICIENCY
ELECTRODES
ELECTROLYSIS
ELEMENTS
FLUIDS
HIGH TEMPERATURE
HYDROGEN COMPOUNDS
HYDROGEN PRODUCTION
HYDROXIDES
KINETICS
LYSIS
MEDIUM TEMPERATURE
METALS
MIXTURES
NICKEL
NONMETALS
OXYGEN
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
POTASSIUM HYDROXIDES
PRODUCTION
REACTION KINETICS
SOLUTIONS
TEMPERATURE DEPENDENCE
TRANSITION ELEMENTS
WATER