Y. Teraoka et al., Identification of active crystalline phase in La-K-Cu-V mixed oxide for the simultaneous removal of nitrogen oxides and diesel soot, B CHEM S J, 72(1), 1999, pp. 133-137
The oxide catalyst having an overall metal composition of La/K/Cu/V = 9/1/7
/3 (denoted as LKCVO) showed an excellent selectivity to NOx reduction into
N-2 in the simultaneous NOx-soot removal reaction, though it was a mixture
of several crystalline phases. In order to identify the real active phase,
LKCVO was characterized by X-ray diffraction (XRD) and by elemental analys
is of individual grains in a transmission electron microscope (TEM) equippe
d with an energy dispersive spectrometer (EDS). LKCVO was found to be compo
sed of CuO and mixed metal oxides analogous to La2CuO4, LaVO4, and La3VO7.
By comparing the catalytic activity of LKCVO with those of single-phase oxi
des synthesized according to the results of XRD and TEM/EDS, (La2-xKx)(Cu0.
95V0.05)O-4 With 0.05 less than or equal to x less than or equal to 0.1 was
identified to be the real active phase in LKCVO for the simultaneous NOx-s
oot removal reaction.