Accession Number:

AD0605708

Title:

A STUDY OF ADSORPTION AND OXIDATION OF CARBON MONOXIDE ON PLATINUM USING CONSTANT-CURRENT PULSES,

Descriptive Note:

Interim rept.,

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s):

Report Date:

1964-04-24

Pagination or Media Count:

11.0

Abstract:

Using single anodic constant-current pulses, the steadystate concentration of both the carbon monoxide already adsorbed on the surface of a bright platinum electrode immersed in 1M H2SO4 and the additional amount of CO adsorbed during the application of the pulse was determined. At potentials of 0.3 to 0.4 v relative to the normal hydrogen electrode, a surface coverage of one CO molecule per surface Pt atom was observed at very low CO partial pressures for CO partial pressures up to 1 atm, the coverage increased to about 1.06 CO molecules per Pt atom, indicating that additional CO physically adsorbs on the base chemisorbed layer. At 1.0 to 1.3 v the rate of adsorption of CO was slower than the rate of diffusion at 25C, and indirect evidence suggests that CO is not adsorbed at potentials above 1.3 v. The mechanism of oxidation of CO appears to be an electrochemical oxidation of water to form chemisorbed oxygen atoms, which then rapidly react with chemisorbed CO to form CO2. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE