Ce-Ti amorphous oxides for selective catalytic reduction of NO with NH3: confirmation of Ce-O-Ti active sites.
The amorphous Ce-Ti mixed oxides were reported to be catalysts for selective catalytic reduction of NO(x) with NH(3), 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 CeO(2) 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 H(2) (H(2)-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).
School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials, University of Jinan, Jinan 250022, China.
Ping
P
Li
Ying
Y
Xin
Qian
Q
Li
Zhongpeng
Z
Wang
Zhaoliang
Z
Zhang
Lirong
L
Zheng
D000641:Ammonia / Q000737:chemistry*; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D008958:Models, Molecular; D009569:Nitric Oxide / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D033362:Powder Diffraction; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
D010087:Oxides; D002563:Cerium; D009569:Nitric Oxide; D000641:Ammonia; D014025:Titanium