Catalysis science of supported vanadium oxide catalysts
1Operando Molecular Spectroscopy and Catalysis Laboratory, Department of Chemical Engineering, Lehigh University, Bethlehem, PA 18015, USA. iew0@lehigh.edu
Dalton Transactions (Cambridge, England : 2003)
|April 26, 2013
Summary
Supported vanadium oxide catalysts are crucial for oxidation reactions. This review details their structures, surface chemistry, and how oxide supports tune catalytic activity, revealing surface vanadia sites as key active components.
Area of Science:
- Catalysis
- Materials Science
- Surface Chemistry
Background:
- Supported vanadium oxide catalysts are widely used in chemical, petroleum, and environmental oxidation processes.
- These catalysts feature a vanadium oxide phase on high surface area oxide supports like Al2O3, SiO2, and TiO2.
Purpose of the Study:
- To review the fundamental aspects of supported vanadium oxide catalysts.
- To explore their molecular and electronic structures, surface chemistry, and structure-reactivity relationships.
Main Methods:
- Utilized advanced in situ characterization techniques including Raman, IR, UV-vis, XANES, EXAFS, solid-state (51)V NMR, and isotopic oxygen exchange.
- Conducted surface chemistry and reactivity studies.
Main Results:
- Characterization revealed that supported vanadium oxide phases exist as two-dimensional surface vanadia sites on oxide supports.
- Surface vanadia sites were identified as the primary active sites for oxidation reactions.
- The oxide support significantly influences the redox properties of surface vanadia sites, with variations up to ~10^3.
Conclusions:
- Supported vanadium oxide catalysts' activity is governed by surface vanadia sites.
- The choice of oxide support critically controls the catalytic performance by modulating the redox properties of these active sites.
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