摘要:
Device for the purification of exhaust gases from a thermal combustion engine comprising:one or several ceramic catalyst carriers comprising an arrangement of crystallites of the same size, same isodiametric morphology and same chemical composition, or approximately the same size, same isodiametric morphology and same chemical composition in which each crystallite is in point or quasi-point contact with the surrounding crystallites, andone or several active phases for chemical destruction of impurities in the exhaust gas comprising metallic particles mechanically anchored in said catalyst carrier such that coalescence and mobility of each particle are limited to a maximum volume corresponding to the volume of a crystallite of said ceramic catalyst carrier.
摘要:
Catalyst comprising: a) a catalytic ceramic support comprising an arrangement of crystallites of the same size, same isodiametric morphology and same chemical composition or substantially of the same size, same isodiametric morphology and same chemical composition in which each crystallite is in point contact or virtually point contact with crystallites that surround it, and b) at least one active phase comprising metallic particles mechanically anchored into said catalytic support so that the coalescence and the mobility of each particle are limited to a volume corresponding to that of a crystallite of said catalytic ceramic support.
摘要:
An architecture made of a ceramic or a metallic foam has at least one continuous and/or discontinuous, axial and/or radial porosity gradient ranging from 10 to 90% associated to a pore size range from 2 to 60 ppi, at least one continuous and/or discontinuous, axial and/or radial concentration gradient of catalytic active(s) phase(s) from 0.01 wt % to 100 wt % preferentially from 0.1 wt % to 20 wt %, and a microstructure with a specific area ranging between 0.1 to 30 m2/g, a grain size between 100 nm and 20 microns and a skeleton densification above 95%.
摘要:
The invention relates to an architecture comprising ceramic or metallic foam, characterized in that the foam has at least one continuous and/or discontinuous, axial and/or radial porosity gradient ranging from 10 to 90%, and a pore size from 2 ppi to 60 ppi, and in that the architecture has a micro structure comprising specific area ranging between 0.1 to 30 m2/g, a grain size between 100 nm and 20 microns and a skeleton densification above 95%. One process to obtain this architecture can be based on the preparation of a ceramic foam with porosity gradient comprising: choosing at least one polymeric sponge, impregnation of the polymeric sponge by a ceramic slurry, drying of the impregnated sponge, pyrolysing the organics including the polymeric sponge, and sintering, and characterized in that we realize a pre-step to obtain a continuous and/or discontinuous porosity gradient.
摘要:
Device for the purification of exhaust gases from a thermal combustion engine comprising:one or several ceramic catalyst carriers comprising an arrangement of crystallites of the same size, same isodiametric morphology and same chemical composition, or approximately the same size, same isodiametric morphology and same chemical composition in which each crystallite is in point or quasi-point contact with the surrounding crystallites, andone or several active phases for chemical destruction of impurities in the exhaust gas comprising metallic particles having chemical interactions with said ceramic catalyst carrier and mechanical anchoring in said catalyst carrier such that coalescence and mobility of each particle are limited to a maximum volume corresponding to the volume of a crystallite of said ceramic catalyst carrier.
摘要:
The invention relates to a catalyst support made of a ceramic, the support comprising an arrangement of crystallites having the same size, the same isodiametric morphology and the same chemical composition or substantially the same size, the same isodiametric morphology and the same chemical composition, in which each crystallite makes point contact or almost point contact with the surrounding crystallites.
摘要:
The invention relates to a catalyst comprising: a) a catalyst support made of a ceramic, the support comprising an arrangement of crystallites having the same size, the same isodiametric morphology and the same chemical composition or substantially the same size, the same isodiametric morphology and the same chemical composition, in which each crystallite makes point contact or almost point contact with the surrounding crystallites; and b) at least one active phase comprising metallic particles that interact chemically with said catalyst support made of a ceramic and that are mechanically anchored to said catalyst support in such a way that the coalescence and mobility of each particle are limited to a maximum volume corresponding to that of a crystallite of said catalyst support.
摘要:
Architecture comprising ceramic or metallic foam, characterized in that the foam has a constant axial and radial porosity between 10 to 90% with a pore size between 2 to 60 ppi, and at least one continuous and/or discontinuous, axial and/or radial concentration of catalytic active(s) phase(s) from 0.01 wt % to 100 wt %, preferentially from 0.1 to 20 wt. %, and in that the architecture has a microstructure comprising specific area ranging between 0.1 to 30 m2/g, a grain size between 100 nm and 20 microns and a skeleton densification above 95%.