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. A catalytic converter comprising:
(a) a base component comprising an oxide of titanium and at least one catalytically active component comprising an oxide of vanadium, a clay binder and optionally fibres that provide mechanical stability; and
(b) at least one porous inorganic filler comprising a diatomaceous earth having at least mesoporosity.
2. The catalytic converter of claim 1 , wherein at least one catalytically active component is an SCR catalyst.
3. The catalytic converter of claim 1 , wherein:
the base component, the at least one catalytically active component, the clay binder, 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 the diatomaceous earth and with the same base component, the catalytically active component, the clay binder, and the fibers, if present, having same defined ratio of proportions relative to one another.
4. The catalytic converter of claim 1 , wherein the diatomaceous earth is present within the range from 5 to 50% by weight relative to the total weight of the catalytic converter.
5. The catalytic converter of claim 4 , wherein the diatomaceous earth is present within the range from 10 to 25% by weight, relative to the weight of the catalytic converter.
6. The catalytic converter of claim 1 , wherein the base component further comprises WO 3 .
7. The catalytic converter of claim 1 , further comprising a molecular sieve.
8. The catalytic converter of claim 7 , wherein the molecular sieve is an aluminosilicate zeolite.
9. The catalytic converter of claim 7 , wherein the molecular sieve has a MFI, BEA, CHA, AEI, FAU, AFX or ERI framework structure.
10. The catalytic converter of claim 7 , wherein the molecular sieve comprises a metallic activator.
11. The catalytic converter of claim 7 , wherein the molecular sieve comprises an ion-exchanged zeolite.
12. The catalytic converter of claim 1 that is in a form of an extruded catalytic converter.
13. The catalytic converter of claim 12 that is a honeycomb catalytic converter.
14. The catalytic converter of claim 1 that is in a form of a wall-flow filter.
15. The catalytic converter of claim 1 , comprising TiO 2 and V 2 O 5 present in a weight ratio of from 20 to 60.
16. The catalytic converter of claim 1 , wherein the base component comprises an oxidic titanium-vanadium-tungsten catalytic system.
17. The catalytic converter of claim 1 , comprising an extruded composition of:
(a) titanium dioxide, present in a range of from 60 to 80 wt %;
(b) vanadium pentoxide, present in a range of from 1 to 2.5 wt %;
(c) tungsten trioxide, present in a range of from 4 to 14 wt %;
(d) an aluminosilicate clay binder, present in a range of from 4 to 10 wt %;
(e) diatomaceous earth, present in a range of from 4 to 20 wt %; and optionally
(f) glass fibers, which when present are present in a range of from 4 to 10 wt %;
wherein the weight percentages in each case are with respect to the weight of the entire extruded composition.
18. The catalytic converter of claim 1 , wherein the base component comprises an oxidic titanium-vanadium-iron catalytic system.