Abstract: The present invention discloses emissions treatment systems for the removal of NOx from exhaust combustion gases comprising, in the following order, from upstream to downstream: a) means for the injection of ammonia or an ammonia precursor solution into the exhaust gas stream, and b) a catalytic device comprising at least one carrier substrate, a material zone A comprising a first V/TiO2 SCR catalytically active composition SCRfirst which comprises at least one oxide of vanadium supported on titanium dioxide, a material zone B comprising a second V/TiO2 SCR catalytically active composition SCRsecond which comprises at least one oxide of vanadium supported on titanium dioxide, wherein the two material zones are affixed to the at least one carrier substrate in such a way that the exhaust gas first comes into contact with material zone A and then with material zone B, and wherein the ratio Vfirst:Vsecond of the percentages of vanadium contained in the first to the second V/TiO2 SCR catalytically active compositi

Abstract: The present invention disclose catalyst compositions for the selective catalytic reduction of nitrogen oxides, consisting of at least one oxide of vanadium in an amount of 2.0 to 4.0 wt.-%, calculated as V2O5 and based on the total weight of the catalyst composition, at least one oxide of tungsten in an amount of 2.5 to 7.2 wt.-%, calculated as WO3 and based on the total weight of the catalyst composition, at least one oxide of antimony in an amount of 0.6 to 3.4 wt.-%, calculated as Sb2O5 and based on the total weight of the catalyst composition, at least one oxide of zirconium in an amount of 0 to 1.0 wt.-%, calculated as ZrO2 and based on the total weight of the catalyst, and at least one oxide of titanium in an amount of 84.6 to 94.9 wt.-% calculated as TiO2 and based on the total weight of the catalyst, wherein the weight ratio of the oxides of vanadium, tungsten, antimony, titanium and optionally zirconium, calculated as V2O5, WO3, Sb2O5, TiO2 and optionally ZrC2, respectively, add up to 100 wt.-%.