摘要 |
Catalyst compositions for reducing nitrogen oxide emissions during gas processing. In a first embodiment, the compositions are characterised in that they are based on at least one element selected from the group which consists of tantalum, vanadium, niobium and antimony. In a second embodiment, they are characterised in that they are based on at least one element selected from a first group which includes tantalum, vanadium, niobium and antimony, plus at least one other element selected from a second group which includes copper, silver and gold. In a third embodiment, the compositions are based on at least one element selected from a first group which includes tantalum, vanadium, niobium, antimony and copper, plus at least one other element selected from a second group which includes zinc and the elements in groups IIIb, IVb and Vb of the periodic table. In a fourth embodiment, the compositions include copper and at least one other element selected from group VIa of the periodic table. |