jz7b00273_si_001.pdf (2.68 MB)
Dissociative Water Adsorption by Al3O4+ in the Gas Phase
journal contribution
posted on 2017-03-06, 12:50 authored by Matias
R. Fagiani, Xiaowei Song, Sreekanta Debnath, Sandy Gewinner, Wieland Schöllkopf, Knut R. Asmis, Florian A. Bischoff, Fabian Müller, Joachim SauerWe
use cryogenic ion trap vibrational spectroscopy in combination
with density functional theory (DFT) to study the adsorption of up
to four water molecules on Al3O4+. The infrared photodissociation spectra of [Al3O4(D2O)1–4]+ are measured
in the O–D stretching (3000–2000 cm–1) as well as the fingerprint spectral region (1300–400 cm–1) and are assigned based on a comparison with simulated
harmonic infrared spectra for global minimum-energy structures obtained
with DFT. We find that dissociative water adsorption is favored in
all cases. The unambiguous assignment of the vibrational spectra of
these gas phase model systems allows identifying characteristic spectral
regions for O–D and O–H stretching modes of terminal
(μ1) and bridging (μ2) hydroxyl
groups in aluminum oxide/water systems, which sheds new light on controversial
assignments for solid Al2O3 phases.