Nickel based alloys as electrocatalysts for oxygen evolution from alkaline solutions. [Metal--air batteries]

Technical Report · Sat Jan 01 00:00:00 EST 1977

DOI:https://doi.org/10.2172/7215746· OSTI ID:7215746

Lu, P. W.T.; Srinivasan, S.

The slowness of the oxygen evolution reaction is one of the main reasons for significant energy losses in water electrolysis cells and secondary air--metal batteries. To date, data on the kinetics of this reaction on alloys and intermetallic compounds are sparse. In this work, mechanically polished alloys of nickel with Ir, Ru or W and Ni--Ti intermetallic compounds were studied as oxygen electrodes. Since the oxygen evolution reaction always takes place on oxide-film covered surfaces, the nature of oxide films formed on these alloys were investigated using cyclic voltametric techniques. Steady-state potentiostatic and slow potentiodynamic (at 0.1 mV/s) methods were employed to obtain the electrode kinetic parameters for the oxygen evolution reaction in 30 wt. percent KOH at 80/sup 0/C, the conditions normally used in water electrolysis cells. The peaks for the formation or reduction of oxygen-containing layers appearing on the pure metals are not always found on the alloys. The maximum decreases in oxygen overpotential at an apparent current density of 20 mA cm/sup -2/ (as compared with that on Ni) were found for the alloys of 50Ni--50Ir and 75Ni--25Ru and the intermetallic compound Ni/sub 3/Ti, these decreases being about 40, 30, and 20 mV, respectively. On the long-term polarization in the potential region of oxygen evolution, the oxygen-containing layers on Ni--Ir or Ni--Ru alloys are essentially composed of nickel oxides instead of true mixed oxide films of two components. The present work confirms that, possibly because of coverage by oxide films, there is no direct dependence of the electrocatalytic activities of the alloys on their electronic properties. 11 figures, 1 table.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• DOE Contract Number: EY-76-C-02-0016
• OSTI ID: 7215746
• Report Number(s): BNL-22275
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
25 ENERGY STORAGE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ELECTROLYTIC CELLS
ELECTRODES
IRIDIUM ALLOYS
CHEMICAL REACTION KINETICS
METAL-GAS BATTERIES
CATHODES
NICKEL BASE ALLOYS
RUTHENIUM ALLOYS
TITANIUM ALLOYS
TUNGSTEN ALLOYS
AIR
BINARY ALLOY SYSTEMS
CATALYSTS
ELECTROCHEMISTRY
ELECTROLYSIS
INTERMETALLIC COMPOUNDS
MEDIUM TEMPERATURE
OXIDATION
OXIDES
POLARIZATION
POTASSIUM HYDROXIDES
ALKALI METAL COMPOUNDS
ALLOY SYSTEMS
ALLOYS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
ELECTRIC BATTERIES
ELECTROCHEMICAL CELLS
ENERGY STORAGE SYSTEMS
FLUIDS
GASES
HYDROGEN COMPOUNDS
HYDROXIDES
KINETICS
LYSIS
NICKEL ALLOYS
OXYGEN COMPOUNDS
PLATINUM METAL ALLOYS
POTASSIUM COMPOUNDS
REACTION KINETICS
360105* - Metals & Alloys- Corrosion & Erosion
250903 - Energy Storage- Batteries- Materials
Components
& Auxiliaries
400201 - Chemical & Physicochemical Properties