KINETICS OF REDUCTIVE ABSORPTION OF CO2 ON SMOOTH Pt ELECTRODES.
Interim technical rept. no. 4,
TYCO LABS INC WALTHAM MASS
Pagination or Media Count:
The formation kinetics of the adsorbed species reduced CO2 CO2 have been studied with Pt electrodes in 1 M H2SO4 at 40C. Electrochemical transient techniques have been used for characterization of the adsorbate both during its formation and at steady state. Steady state coverage is high and potential independent between 0.00 and 0.25 vs. RHE. The implication of these results for the role of CO2 in the overall fuel to CO2 reaction is discussed. The steady state CO2 adsorbate has the same composition over the whole potential range investigated and comprises two parts. During the approach to the steady state at any potential, the relative amounts of the two components of the adsorbate change. The major component is found at all coverages and comprises the total adsorbate for organic coverage. This species has been suggested to have the composition either C 0 or C-OH. Initial adsorption rates are first order in CO2 and adsorbed hydrogen and zero order in free surface. The reaction at low coverage is suggested to occur via a pre-adsorbed CO2 layer similar to the type C adsorbed hydrogen postulated in gas phase adsorption studies.
- Physical Chemistry