The catalytic activities of MnOx-WO3/TiO2 catalyst in a wide temperature range were investigated for selective catalytic reduction (SCR）of NO with NH3.It yields 80.3%—99.6% NOx conversion and 98.7%—100% selectivity for N2 product from 100℃ to 350℃ at GHSV 18900 h-1.In the presence of 0.01% SO2 and 6% H2O at 120℃

the NOx conversion maintains at 98.5%.At 300℃ and with 0.07% SO2 in the reactant stream

the NOx conversion is 99%

as high as that of the commercial V-W/TiO2 catalyst.The steady-state kinetic study shows that O2 plays a promoting role.When O2 content is less than 1.5%

the NOx conversion increases sharply with O2 concentration.The reaction order is zero with respect to NH3 and first with respect to NO with excess O2 and H2O.The active energy of Mn-W/TiO2 calculated is 6.24 kJ·mol-1 according to the kinetic experiments at various temperatures

much lower than other catalysts reported in the literatures.Thus Mn-W/TiO2 is an excellent catalyst for SCR NO with NH3.