A new type catalyst which contains manganese oxides supported on TiO2(MnOx/TiO2)has been prepared

and a test study on MnOx/TiO2 with various loadings of manganese and different calcination temperature for selective catalytic reduction(SCR)of NOx with NH3 under low temperature being carried out.Results show that the conversion rate of NOx increases with the amount of manganese

while the selectivity of N2 decreases with it

and the calcination temperature affecting the catalytic activity and the selectivity of N2 at the same time.By using the test means

such as x-ray diffraction(XRD)

specific surface area

porous volume

aperture

as well as Fourier transform infrared(FT-IR)spectroscope

temperaure-rise programmed reduction(TPR)and NH3 temperature programmed desorption(NH3-TPD)etc.

the optimal preparing condition for MnOx/TiO2 catalyst has been found.It has been found that:under situation of same loadings(may regard as same Mn content)

both catalytic activity and selectivity of N2 for MnO2 are higher than that of mixture for MnO2 and Mn2O3;at guaranteed hourly space velocity(GHSV)of 12 600 h-1

the conversion rate of NOx yied 97% at 80 ℃

and nearly 100% conversion rate and 100% selectivity of N2 at 120 ℃.Results of test show that the catalytic system of MnO2/TiO2

acting as a basis for SCR of NOx with NH3 under low temperature

has important theoritic and practical significance.