Ce–Ti Amorphous Oxides for Selective Catalytic Reduction of NO with NH3: Confirmation of Ce–O–Ti Active Sites
- 21 August 2012
- journal article
- research article
- Published by American Chemical Society (ACS) in Environmental Science & Technology
- Vol. 46 (17), 9600-9605
- https://doi.org/10.1021/es301661r
Abstract
The amorphous Ce–Ti mixed oxides were reported to be catalysts for selective catalytic reduction of NOx with NH3, in which Ce and not Ti acts as their solvent in spite of the fact that Ce is low in content. The amorphous catalysts were characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) equipped with selective area electron diffraction (SAED). The Ce–Ti amorphous oxide shows higher activity than its crystalline counterpart at lower temperatures. Moreover, the presence of small CeO2 crystallites as for the impregnated sample is deleterious to activity. The Ce–O–Ti short-range order species with the interaction between Ce and Ti in atomic scale was confirmed for the first time to be the active site using temperature programmed reduction with H2 (H2–TPR), in situ FTIR spectra of NO adsorption, X-ray photoelectron spectroscopy (XPS), and X-ray absorption fine-structure (XAFS). Lastly, the Ce–O–Ti structure was directly observed by field-emission TEM (FETEM).Keywords
This publication has 40 references indexed in Scilit:
- Hydrothermal Method Prepared Ce‐P‐O Catalyst for the Selective Catalytic Reduction of NO with NH3 in a Broad Temperature RangeChemCatChem, 2010
- Preparation and characterization of CeO2/TiO2 catalysts for selective catalytic reduction of NO with NH3Catalysis Communications, 2010
- The activity and characterization of CeO2-TiO2 catalysts prepared by the sol–gel method for selective catalytic reduction of NO with NH3Journal of Hazardous Materials, 2009
- Selective catalytic reduction of NO by NH3 over a Ce/TiO2 catalystCatalysis Communications, 2008
- WO3/CeO2-ZrO2, a promising catalyst for selective catalytic reduction (SCR) of NOx with NH3 in diesel exhaustChemical Communications, 2008
- Characterization and FTIR Studies of MnOx−CeO2 Catalyst for Low-Temperature Selective Catalytic Reduction of NO with NH3The Journal of Physical Chemistry B, 2004
- MnOx-CeO2 mixed oxides prepared by co-precipitation for selective catalytic reduction of NO with NH3 at low temperaturesApplied Catalysis B: Environment and Energy, 2004
- Performance and kinetics study for low-temperature SCR of NO with NH3 over MnOx–CeO2 catalystJournal of Catalysis, 2003
- A superior catalyst for low-temperature NO reduction with NH3Chemical Communications, 2003
- Chemical and mechanistic aspects of the selective catalytic reduction of NOx by ammonia over oxide catalysts: A reviewApplied Catalysis B: Environment and Energy, 1998