Patent ID: 11946405
Assignee: BASF SE
Field: Chemical engineering (Chemistry)
Classification: CPC F  B  Y | IPC B  F

Claim 14:
15. A process for preparing the four-way conversion catalyst according to claim 1, comprising:
(i) providing a porous wall-flow filter substrate comprising an inlet end, an outlet end, a substrate axial length extending between the inlet end and the outlet end, and a plurality of passages defined by porous internal walls of the porous wall-flow filter substrate, wherein the plurality of passages comprise inlet passages with an open inlet end and a closed outlet end, and outlet passages with a closed inlet end and an open outlet end, wherein the interface between the passages and the porous internal walls is defined by the surface of the internal walls, wherein the internal walls have an average pore size in the range of from 10 micrometers to 30 micrometers, and wherein the average porosity of the internal walls ranges from 25% to 75%;
(ii) providing a slurry comprising particles of a source of the oxidic component, the particles having a Dv90 value ranging from 0.005 micrometers to 20 micrometers; coating the porous internal walls of the porous wall-flow filter substrate provided in (i) with the particles of the slurry; calcining the obtained coated filter substrate, obtaining the filter substrate comprising the oxidic component; and
(iii) providing a slurry comprising particles of a source of the first three-way conversion catalytic coating, the particles having a Dv90 value ranging from 2 micrometers to 25 micrometers; coating the porous internal walls of the porous wall-flow filter substrate obtained in (ii) with the particles of the slurry; calcining the obtained coated filter substrate, obtaining the filter substrate comprising the oxidic component and the first three-way conversion catalytic coating.