Catalytic converter
In order to specify a catalytic converter, especially SCR catalytic converter, with maximum catalytic activity, this catalytic converter has at least one catalytically active component and additionally at least one porous inorganic filler component having meso- or macroporosity. The organic porous filler component has a proportion of about 5 to 50% by weight. More particularly, a diatomaceous earth or a pillared clay material is used as the porous inorganic filler component.
1. An SCR catalytic converter for reducing nitrogen oxides to nitrogen in the presence of ammonia and oxygen, comprising:
(a) a base component comprising at least one catalytically active component, a binder component and optionally fibres that provide mechanical stability, wherein: (i) the SCR catalytic converter comprises a titanium-vanadium system and the catalytically active component comprises vanadium; or (ii) the catalytically active component comprises a molecular sieve; and
(b) at least one porous inorganic filler component, which is a pillared clay material having two-dimensional clay layers spaced apart by inorganic pillars, wherein the inorganic filler component has at least microporosity;
wherein the porous filler is catalytically inactive.
2. The catalytic converter according to claim 1 , wherein:
the at least one catalytically active component, the binder component, and the fibers, if present, are present in a defined ratio of proportions by weight relative to one another, and
the catalytic converter has at least a same catalytic activity as a comparative catalytic converter without a filler component and with the same catalytically active component, the binder component, and the fibers, if present, having same defined ratio of proportions relative to one another.
3. The catalytic converter according to claim 1 , wherein the inorganic porous filler component is present within the range from 5 to 50% by weight relative to the total weight of the catalytic converter.
4. The catalytic converter according to claim 3 , wherein the inorganic porous filler component is present within the range from 10 to 25% by weight, relative to the weight of the catalytic converter.
5. The catalytic converter according to claim 1 , wherein the titanium-vanadium system is present in a proportion by weight of 70-90% relative to the weight of the catalytic converter.
6. The catalytic converter according to claim 1 , wherein the molecular sieve is an aluminosilicate zeolite.
7. The catalytic converter according to claim 1 , wherein the at least one catalytically active component comprises a molecular sieve having the MFI, BEA, CHA, AEI, FAU, AFX or ERI framework structure.
8. The catalytic converter according to claim 1 , wherein the molecular sieve comprises a metallic activator.
9. The catalytic converter according to claim 1 , wherein the molecular sieve comprises an ion-exchanged zeolite.
10. The catalytic converter according to claim 1 , wherein the catalytic converter is in a form of an extruded catalytic converter.
11. The catalytic converter according to claim 10 , wherein the extruded catalytic converter is a honeycomb catalytic converter.
12. The catalytic converter according to claim 1 , wherein the catalytic converter is in a form of a wall-flow filter.