Accession Number : ADA183485

Title :   In-Situ Surface EXAFS at Chemically Modified Electrodes.

Descriptive Note : Technical rept. no. 7, Oct 86-Jul 87,

Corporate Author : CORNELL UNIV ITHACA NY BAKER LAB

Personal Author(s) : Albarelli,M J ; White,J H ; McMillan,M ; Abruna,H D

PDF Url : ADA183485

Report Date : 28 Jul 1987

Pagination or Media Count : 25

Abstract : The surface EXAFS and near edge structure of electropolymerized films of Ru(v-bpy)32+ on platinum electrodes have been studied as a function of surface coverage and applied potential by measuring the characteristic RuKa fluorescence intensity. Spectra for electrodes modified with 1, 5 and 50 monolayers were obtained. Analysis and comparison of EXAFS and XANES features for these films with those of bulk Ru(bpy)32+ showed similar morphological and electronic characteristics in agreement with previous electrochemical studies showing that solution redox properties of monomer complexes can be transferred to electrode surfaces by electrodeposition as polymer films of varying thickness. Electrochemical oxidation of the films resulted in a shift of 2 eV in the edge position towards higher energy, consistent with the higher charge on the ruthenium centers. Other spectral features, however, remained essentially unchanged. The applicability of these studies to the in-situ investigation of electrocatalytic systems is discussed. Keywords: Modified electrodes, Synchrotron radiation.

Descriptors :   *ELECTRODES, *ELECTROCATALYSTS, *ELECTROCHEMISTRY, *ELECTRODEPOSITION, *PLATINUM, EDGES, POSITION(LOCATION), FLUORESCENCE, INTENSITY, SURFACES, MORPHOLOGY, ELECTRONICS, ENERGY, MONOMERS, RUTHENIUM, THICKNESS, POLYMERIC FILMS, OXIDATION REDUCTION REACTIONS, SOLUTIONS(GENERAL), RADIATION, SYNCHROTRONS

Subject Categories : Inorganic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE