Extruded monolithic catalytic converter and manufacturing method
AssigneeArgillon GmbH
InventorsLothar Hofmann, Jörg Münch, Ralf Dotzel
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Abstract
The invention relates to an extruded solid catalyst body for breaking down nitrogen oxides in the presence of a reducing agent as well as to a process for manufacture of said body. The solid catalyst body has an active material that contains 60 to 87% by weight of an ion-exchanged zeolite containing at least one metal from the group containing Cu, Hf, La, Au, In, V, lanthanoids and transition metals of group VIII of the periodic system, more than 10 to 37% by weight of aluminum oxide and 2 to 10% by weight of inorganic fibers. The solid catalyst body, the active material of which contains a zeolite can be manufactured by extrusion and has a high degree of mechanical stability at a high catalytic activity.
Claims25
An extruded solid catalyst body for breaking down nitrogen oxides in the presence of a reducing agent, the catalyst body comprising:
- active material containing 60 to 87% by weight of an ion-exchanged zeolite, said zeolite containing at least one metal selected from the group consisting of Cu, Hf, La, Au, In, V, lanthanides, and transition metals of the group VIII of the periodic system, more than 10% and up to 37% by weight of aluminum oxide, and 2 to 10% by weight of inorganic fibers.
A process of manufacturing a solid catalyst body, the process which comprises:
- mixing starting materials of a zeolite and of an aluminum oxide or a precursor substance of the aluminum oxide, each in powder form, with inorganic fibers;
- optionally adding an organic auxiliary agent;
- processing by mixing and/or kneading in an acid or alkaline aqueous solution into a plastic compound to form a mixture;
- extruding the mixture into a catalyst body, drying the catalyst body and calcining at a temperature between 550 and 650° C. to form a solid catalyst body;
- and
- selecting quantitative proportions of the starting materials such that the solid catalyst body contains 60 to 87% by weight of an ion-exchanged zeolite containing at least one metal selected from the group consisting of Cu, Hf, La, Au, In, V, lanthanides, and transition metals of group VIII of the periodic system, more than 10% and up to 37% by weight of aluminum oxide, and 2 to 10% by weight of the inorganic fibers.
Dependencies are inferred from the claim text.