Molecular beam scattering measurements on anatase TiO2(001) and
rutile TiO2(110)
EMSL Project ID
18900
Abstract
Heterogeneous catalysis is a key industry in our modern technological world. Despite the pertinent economic impact of heterogeneous catalysis, the mechanistic understanding of chemical reaction dynamics/kinetics is still surprisingly poor. Multi-component catalysts are necessarily optimized by intelligent trial-and-error approaches. Therefore, we propose studies on planar model catalysts with the aim of obtaining a more comprehensive mechanistic understanding, including the structure-activity relationship (SAR) on "simpler" but well-defined model systems by means of surface chemistry techniques. The ultimate goal is to tune structural properties for optimizing the electronic, mechanical, and catalytic performance. Proposed is a surface science study of the adsorption dynamics and kinetics of probe molecules (CO, NO, O2, CO2, H2O) on the catalytically more active anatase polymorph of TiO2(001). Supplementary rutile TiO2(110) will be considered. The probe molecules are important for the CO oxidation and NOx reduction reactions. Furthermore, reactive scattering measurements will be conducted to further characterize the CO oxidation reaction on Au nanoclusters supported on anatase TiO2(001). Thus, we will attempt to bridge the structure gap in catalysis. We will use molecular beam scattering techniques to map the gas-surface energy transfer mechanisms and surface reactions as well as thermal desorption spectroscopy (TDS), He atom TDS, and molecular beam relaxation spectroscopy (MBRS) to study the adsorption kinetics. The TiO2 samples will be characterized by a variety of techniques, including X-ray diffraction (XRD), low energy electron diffraction (LEED), auger electron spectroscopy (AES), and elastic He atom scattering. The results will be compared with prior measurements on rutile TiO2 from the PI?s group as well as published work from other groups to address the question of whether anatase samples are indeed more reactive than rutile surfaces for a given adsorption/reaction process, as proposed in a number of studies.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2006-08-24
End Date
2009-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Adsorption of iso-/n-butane on an anatase thin film: a molecular beam scattering and TDS study,
Catalysis Letters 116 (2007) 9-14,
by J. Goering,1 E. Kadossov,1 U. Burghaus,1- Z.Q. Yu,2,+ S. Thevuthasan,2
L.V. Saraf2, (1NDSU 2PNNL)
Goering J, U Burghaus, BW Arey, O Eidelman, and R Tenne. 2008. "Reactive and non-reactive interactions of thiophene with WS2 fullerene-like nanoparticles: an ultra-high vacuum surface chemistry study ." Catalysis Letters 125(3-4):236-242. doi:10.1007/s10562-008-9565-7
Reactivity screening of anatase TiO2 nanotube arrays and anatase thin films: a surface chemistry point of view, ACS Symposium Series book, "Nanoparticles: Synthesis, Stabilization, Passivation and Functionalization" by S. Funk,1 B. Hokkanen,1 T. Nurkic,1 J. Goering, 1 E. Kadossov, 1 U. Burghaus,1- A. Ghicov,2 P. Schmuki,2 Z.Q. Yu,3 S. Thevuthasan3, L.V. Saraf3
1NDSU; 2Erlangen-Nuernberg; 3PNNL
(The book chapters have been peer-reviewed.)