ON THE STUDY OF ADSORBED SPECIES AT PLATINUM FROM METHANOL, FORMIC AGID AND REDUCED CARBÓN DIOXIDE VIA IN SITU FT-ir SPECTROSCOPY

T. IWASITA W. VIELSTICH; F. C. NART; B. LÓPEZ,; W. VIELSTICH

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 1992 vol. 37 p. 2361 - 2367

0013-4686

Three diñerent coordinated forms of CO adsorbed to the platinum surface were observed formethanol, formic acid and reduced carbon dioxide: linear-, bridge- and multi-bonded CO. Using a new experimental approach absolute absorption bands are observed for the adsorption of methanol and reduced carbon dioxide. Sample spectra are computed with respect to a reference spectrum which is taken before adsorption. In this way the presence of a COH adsórbate is demonstrated. The absolute band procedure must be applied to observe features exhibiting only a small dependence on potential, because in this case using the usual SNIFT-irS procedure (first adsorption and then collection of spectra at two potentials) the signals may cancel out when computing the difierence spectra. Using Pt/Ru as a bifunctional catalyst for water splitting and CO/COH oxidation, surface poisoning during the oxidation of methanol is strongly diminished: current-potential relationships of technical interest are obtained.