Influence of catalyst synthesis method on selective catalytic reduction (SCR) of NO by NH3 with V2O5-WO3/TiO2 catalysts
We compared the molecular structures, surface acidity and catalytic activity for NO/NH3/O2 SCR of V2O5-WO3/TiO2 catalysts for two different synthesis methods: co-precipitation of aqueous vanadium and tungsten oxide precursors with TiO(OH)2 and by incipient wetness impregnation of the aqueous precursors on a reference crystalline TiO2 support (P25; primarily anatase phase). Bulk analysis by XRD showed that co-precipitation results in small and/or poorly ordered TiO2(anatase) particles and that VOx and WOx do not form solid solutions with the bulk titania lattice. Surface analysis of the co-precipitated catalyst by High Sensitivity-Low Energy Ion Scattering (HS-LEIS) confirms that the VOx and WOx are surface segregated for the co-precipitated catalysts. In situ Raman and IR spectroscopy revealed that the vanadium and tungsten oxide components are present as surface mono-oxo O = VO3 and O = WO4 sites on the TiO2 supports. Co-precipitation was shown for the first time to also form new mono-oxo surface VO4 and WO4 sites that appear to be anchored at surface defects of the TiO2 support. IR analysis of chemisorbed ammonia showed the presence of both surface NH3* on Lewis acid sites and surface NH4+* on Brønsted acid sites. TPSR spectroscopy demonstrated that the specific SCR kinetics was controlled bymore »
- Chongqing Univ., Chongqing (China). College of Materials Science and Engineering; Lehigh Univ., Bethlehem, PA (United States). Operando Molecular Spectroscopy & Catalysis Lab.
- Lehigh Univ., Bethlehem, PA (United States). Operando Molecular Spectroscopy & Catalysis Lab.
- Chongqing Univ., Chongqing (China). College of Materials Science and Engineering
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Science Division and Center for Nanophase Materials Sciences
- Publication Date:
- OSTI Identifier:
- Grant/Contract Number:
- AC05-00OR22725; SC0012577; 51274263; 51204220; UNCAGE-ME
- Accepted Manuscript
- Journal Name:
- Applied Catalysis. B, Environmental
- Additional Journal Information:
- Journal Volume: 193; Journal Issue: C; Journal ID: ISSN 0926-3373
- Research Org:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
- Sponsoring Org:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Country of Publication:
- United States
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE Catalysts; Supported; TiO2; V2O5; WO3; Synthesis; Co-precipitation; Incipient-wetness impregnation; Selective catalytic reduction (SCR); NO; NH3; O2; Spectroscopy; Raman; Infrared; TPSR; HS-LEIS; XRD
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