Articolo in rivista, 2006, ENG, 10.1021/la060032l
L. Bedra, M. Rutigliano, M. Balat-Pichelin, M. Cacciatore
Laboratoire Proce´de´s, Mate´riaux et Energie Solaire, PROMES-CNRS, Font-Romeu, France Istituto Metodologie Inorganiche e Plasmi, IMIP-CNR c/o Dipartimento di Chimica, Via Orabona N.4, 70126 Bari, Italy
A joint experimental and theoretical approach has been developed to study oxygen atom recombination on a beta-quartz surface. The experimental MESOX setup has been applied for the direct measurement of the atomic oxygen recombination coefficient gamma at T-S = 1000 K. The time evolution of the relative atomic oxygen concentration in the cell is described by the diffusion equation because the mean free path of the atoms is less than the characteristic dimension of the reactor. The recombination coefficient gamma is then calculated from the concentration profile obtained by visible spectroscopy. We get an experimental value of gamma = 0.008, which is a factor of about 3 less than the gamma value reported for O recombination over beta-cristobalite. The experimental results are discussed and compared with the semiclassical collision dynamics calculations performed on the same catalytic system aimed at determining the basic features of the surface catalytic activity. Agreement, both qualitative and quantitative, between the experimental and the theoretical recombination coefficients has been found that supports the Eley-Rideal recombination mechanism and gives more evidence of the impact that surface crystallographic variation has on catalytic activity. Also, several interesting aspects concerning the energetics and the mechanism of the surface processes involving the oxygen atoms are pointed out and discussed.
Langmuir 22 (17), pp. 7208–7216
Cacciatore Mario Antonio, Rutigliano Maria
ID: 33884
Year: 2006
Type: Articolo in rivista
Creation: 2009-06-16 00:00:00.000
Last update: 2012-04-17 16:19:39.000
CNR authors
CNR institutes
External IDs
CNR OAI-PMH: oai:it.cnr:prodotti:33884
DOI: 10.1021/la060032l
ISI Web of Science (WOS): 000239596300023
Scopus: 2-s2.0-33748567429