Selective catalytic reduction catalyst

A selective catalytic reduction catalyst composition for converting oxides of nitrogen (NOx) in an exhaust gas using a nitrogenous reductant, which catalyst composition comprising a mixture of a first component and a second component, wherein the first component is an admixture of the H-form of an aluminosilicate mordenite zeolite (MOR) and an iron-promoted aluminosilicate MFI zeolite;

• and the second component is a vanadium oxide supported on a metal oxide support, which is titania, silica-stabilized titania or a mixture of both titania and silica-stabilized titania, wherein the weight ratio of the first component to the second component is 10:90 to 25:75 and wherein the weight ratio of the H-form of the aluminosilicate mordenite zeolite (MOR) to the iron-promoted aluminosilicate MFI zeolite is from 3:1 to 3:5.