The introduction of rare earth elements (RE=La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Er and Yb) into a V(2)O(5)/TiO(2)-WO(3)-SiO(2) system leads to a catalyst which shows a significant improvement in thermal stability by hindering transformation of TiO(2) (anatase) into TiO(2) (rutile). As a consequence, these novel compounds show high removal efficiencies for NO, even after aging at 1023 K, when the state of the art SCR catalysts loose activity and selectivity. This allows potential application of these catalysts in the removal of NO., from diesel or lean-burn automotive engines in addition to stationary applications at high temperatures.