Conversion of methanol on rutile TiO2 (110) and tungsten oxide clusters: 1. population of defect-dependent thermal reaction pathways
Open Access
- 17 May 2021
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Physical Chemistry Chemical Physics
- Vol. 23 (21), 12137-12147
- https://doi.org/10.1039/d1cp01175h
Abstract
Tungsten oxide clusters deposited on rutile TiO2 (110) single crystals were used as a model system for heterogenous oxide-oxide bifunctional catalysts. The population of different thermal reaction routes in methanol conversion in the presence of preadsorbed oxygen was probed under UHV conditions. By temperature programmed reaction spectroscopy, we have identified three thermal reaction channels, namely the deoxygenation under formation of methane, the partial oxidation forming formaldehyde and the condensation route under desorption of ethane and dimethyl ether. The specific local reaction environment at the oxidic surface was found to be key for the population of the different reaction channels as exhibited by the introduction of Lewis acidic and basic sites (especially (WO3)n clusters) and available charge carriers such as Ti3+. Especially the amount of bulk Ti3+ interstitials, that can partially transfer charge towards the tungsten oxide clusters at the TiO2 surface, was found to be a key parameter that enables a relatively high methanol conversion in thermal reactions. It turned out that the deoxygenation is by far the most dominant reaction followed by the partial oxidation. The condensation is observed only in low amounts under special conditions, but is an interesting example for reactivity at defect sites.Funding Information
- Studienstiftung des Deutschen Volkes
- Deutsche Forschungsgemeinschaft (GRK 2226)
This publication has 50 references indexed in Scilit:
- Adsorption and Decomposition of DMMP on Size‐Selected (WO3)3 ClustersChemistrySelect, 2018
- Oxidation, Reduction, and Condensation of Alcohols over (MO3)3 (M = Mo, W) NanoclustersThe Journal of Physical Chemistry C, 2014
- Catalytic Dehydration of 2-Propanol by Size-Selected (WO3)n and (MoO3)n Metal Oxide ClustersThe Journal of Physical Chemistry C, 2014
- Ethanol Conversion on Cyclic (MO3)3 (M = Mo, W) ClustersThe Journal of Physical Chemistry C, 2014
- Dehydration, dehydrogenation, and condensation of alcohols on supported oxide catalysts based on cyclic (WO3)3 and (MoO3)3 clustersChemical Society Reviews, 2014
- Tungsten Oxide in Catalysis and Photocatalysis: Hints from DFTTopics in Catalysis, 2013
- Radical versus Nucleophilic Mechanism of Formaldehyde Polymerization Catalyzed by (WO3)3 Clusters on Reduced or Stoichiometric TiO2(110)Journal of the American Chemical Society, 2012
- Polymerization of Formaldehyde and Acetaldehyde on Ordered (WO3)3 Films on Pt(111)The Journal of Physical Chemistry C, 2011
- Formaldehyde Polymerization on (WO3)3/TiO2(110) Model CatalystThe Journal of Physical Chemistry C, 2010
- Catalytic Dehydration of 2-Propanol on (WO3)3 Clusters on TiO2(110)Journal of the American Chemical Society, 2008