Vibrational Analysis of H2 and D2 Adsorption on Pt/SiO2
Artikel i vetenskaplig tidskrift, 2005

Vibrational properties of surface species formed upon H2 and D2 exposure of silica supported platinum particles have been investigated with in situ diffuse reflection infrared Fourier transform spectroscopy. Experiments have been performed at 50-250 degrees C, using different platinum loading of the samples in the absence and presence of oxygen. In addition, electronic structure calculations and vibrational analysis have been performed within the density functional theory for H adsorption on a silica cluster, (HO)(3)SiOSi(OH)(3). The spectroscopy experiments showed reversible formation of isolated OH and OD groups on the silica surface when the samples were exposed to H2 and D2, respectively. In addition to the absorption peak corresponding to isolated OH and OD groups, an intense broad band was observed around 3270 cm(-1) (2500 cm(-1)) during H2 (D2) exposure. Supported by the calculations, this band was assigned to perturbed OH groups on the silica surface. The surface coverage of new OH groups was found to correlate to the platinum loading in the samples, indicating that the new silanol groups were formed in the vicinity of the Pt particles. In the investigated temperature interval, the formation rate of CH groups was not found to be temperature dependent.

SILICA

1ST-PRINCIPLES CALCULATIONS

HYDROXYL-GROUPS

SURFACE

MOLECULES

AEROSIL

CHEMICAL SENSORS

SPILT-OVER HYDROGEN

FIELD-EFFECT DEVICES

SIO2

Författare

Mikaela Wallin

Kompetenscentrum katalys (KCK)

Chalmers, Kemi- och bioteknik

Henrik Grönbeck

Chalmers, Teknisk fysik, Kemisk fysik

Kompetenscentrum katalys (KCK)

A. Lloyd Spetz

Linköpings universitet

Mats Eriksson

Linköpings universitet

Magnus Skoglundh

Chalmers, Kemi- och bioteknik

Kompetenscentrum katalys (KCK)

Journal of Physical Chemistry B

1520-6106 (ISSN) 1520-5207 (eISSN)

Vol. 109 19 9581-9588

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Transport

Energi

Materialvetenskap

Ämneskategorier

Fysik

Kemiteknik

DOI

10.1021/jp044759z

Mer information

Senast uppdaterat

2018-02-28