Voltammetric characterization of ruthenium oxide-based aerogels and other RuO{sub 2} solids: The nature of capacitance in nanostructured materials

Journal Article · Tue Feb 02 04:00:00 EST 1999 · Langmuir

DOI:https://doi.org/10.1021/la980785a· OSTI ID:680008

Long, J W; Swider, K E; Merzbacher, C I; Rolison, D R ^[1]

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1. Naval Research Lab., Washington, DC (United States)

Ruthenium dioxide is an important electrode material for applications in electrocatalysis and power sources. High surface areas are achieved in hydrous RuO{sub 2} precipitates and in mixed ruthenium oxide-titanium oxide, (Ru-Ti)O{sub x}, aerogels ( in which nanoscale domains are networked to form a highly porous structure). The electrochemical properties of (Ru-Ti)O{sub x} aerogels, RuO{sub 2}, and hydrous RuO{sub 2} are examined by direct pressing of sub-milligram quantities of the solid onto the surface of a conductive carbon/wax composite. Voltammetric measurements in acidic electrolyte confirm a pseudocapacitive response for all the RuO{sub x}-based materials. Despite an improvement in BET surface area, as compared with other RuO{sub 2} materials, the (Ru-Ti)O{sub x} aerogel displays a low specific capacitance, which correlated to the high degree of crystallinity of the aerogel. Nanocrystallites of rutile RuO{sub 2}, formed during thermal treatment of the sol-gel Ru/Ti precursors, deleteriously affect the specific capacitance of the material; however, all RuO{sub x} domains in the aerogel are voltammetrically addressable. The influence of proton-donating species on the observed capacitance for the (Ru-Ti)O{sub x} aerogel is evident from the dependence of the voltammetric charge in acidic electrolyte on the potential scan rate.

• OSTI ID: 680008
• Report Number(s): CONF-980314--
• Journal Information: Langmuir, Journal Name: Langmuir Journal Issue: 3 Vol. 15; ISSN LANGD5; ISSN 0743-7463
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
ALCOHOL FUEL CELLS
CAPACITANCE
ELECTRIC CONDUCTIVITY
ELECTROCATALYSTS
RUTHENIUM OXIDES
SURFACE AREA
TITANIUM OXIDES