Patent classifications
B01J2523/3718
Synthesis of high surface area, high entropy oxides
High surface area, high entropy oxides comprising multiple metal cations in a single-phase fluorite lattice material enables intrinsic catalytic activity without platinum group metals, tunable oxygen storage capacity, and thermal stability. These properties can be obtained through a facile sol-gel synthesis to provide a low-temperature route for production of phase-pure multi-cationic oxides. The resulting materials achieved significantly higher surface area and catalytic performance, taking advantage of all the properties endowed by the various cations in the composition.
Synthesis of high surface area, high entropy oxides
High surface area, high entropy oxides comprising multiple metal cations in a single-phase fluorite lattice material enables intrinsic catalytic activity without platinum group metals, tunable oxygen storage capacity, and thermal stability. These properties can be obtained through a facile sol-gel synthesis to provide a low-temperature route for production of phase-pure multi-cationic oxides. The resulting materials achieved significantly higher surface area and catalytic performance, taking advantage of all the properties endowed by the various cations in the composition.
HIGH ENTROPY RARE EARTH OXIDES FOR EMISSIONS CONTROL
Methods and systems are provided for an emissions aftertreatment device. In one example, the emissions aftertreatment device may include a catalyst and a high entropy oxygen storage material formed of at least five metal oxides in equal molar proportions. The at least five metal oxides includes one or more rare earth metals as well as other metals with similar chemical properties as the rare earth metals.
Oxygen storage material and method for producing the same
An oxygen storage material including a ceria-zirconia based composite oxide containing a composite oxide of ceria and zirconia, wherein the ceria-zirconia based composite oxide comprises at least one rare-earth element selected from the group consisting of lanthanum, yttrium, and neodymium, and an amount of the rare-earth element(s) contained in total is 1 to 10% by atom in terms of element relative to a total amount of cerium and zirconium in the ceria-zirconia based composite oxide, 60 to 85% by atom of the entire amount of the rare-earth element(s) is contained in a near-surface upper-layer region extending from a surface of each primary particle of the ceria-zirconia based composite oxide to a depth of 50 nm in the primary particle, and 15 to 40% by atom of the entire amount of the rare-earth element(s) is contained in a near-surface lower-layer region extending from a depth of 50 nm to a depth of 100 nm in the primary particle, a content ratio of cerium and zirconium in the ceria-zirconia based composite oxide is in a range of 40:60 to 60:40 in terms of an atomic ratio ([Ce]:[Zr]), and the ceria-zirconia based composite oxide has an intensity ratio {I(14/29) value} between a diffraction line at 2θ=14.5° and a diffraction line at 2θ=29° which satisfies the following condition:
I(14/29) value≥0.032,
where the intensity ratio {I(14/29) value} is determined from an X-ray diffraction pattern using CuKα obtained by an X-ray diffraction measurement conducted after heating in air under a temperature condition of 1100° C. for 5 hours.
Oxygen storage material and method for producing the same
An oxygen storage material including a ceria-zirconia based composite oxide containing a composite oxide of ceria and zirconia, wherein the ceria-zirconia based composite oxide comprises at least one rare-earth element selected from the group consisting of lanthanum, yttrium, and neodymium, and an amount of the rare-earth element(s) contained in total is 1 to 10% by atom in terms of element relative to a total amount of cerium and zirconium in the ceria-zirconia based composite oxide, 60 to 85% by atom of the entire amount of the rare-earth element(s) is contained in a near-surface upper-layer region extending from a surface of each primary particle of the ceria-zirconia based composite oxide to a depth of 50 nm in the primary particle, and 15 to 40% by atom of the entire amount of the rare-earth element(s) is contained in a near-surface lower-layer region extending from a depth of 50 nm to a depth of 100 nm in the primary particle, a content ratio of cerium and zirconium in the ceria-zirconia based composite oxide is in a range of 40:60 to 60:40 in terms of an atomic ratio ([Ce]:[Zr]), and the ceria-zirconia based composite oxide has an intensity ratio {I(14/29) value} between a diffraction line at 2θ=14.5° and a diffraction line at 2θ=29° which satisfies the following condition:
I(14/29) value≥0.032,
where the intensity ratio {I(14/29) value} is determined from an X-ray diffraction pattern using CuKα obtained by an X-ray diffraction measurement conducted after heating in air under a temperature condition of 1100° C. for 5 hours.
AN EMMISSION CONTROL CATALYST ARTICLE WITH ENRICHED PGM ZONE
The present disclosure generally relates to emission control catalyst articles comprising a platinum group metal (PGM) enriched zone, methods of making such emission control catalyst articles, and methods of using such emission control catalyst articles.
AN EMMISSION CONTROL CATALYST ARTICLE WITH ENRICHED PGM ZONE
The present disclosure generally relates to emission control catalyst articles comprising a platinum group metal (PGM) enriched zone, methods of making such emission control catalyst articles, and methods of using such emission control catalyst articles.
Mixed cerium- and zirconium-based oxide
The present invention relates to a mixed oxide of aluminium, of zirconium, of cerium, of lanthanum and optionally of at least one rare-earth metal other than cerium and lanthanum that makes it possible to prepare a catalyst that retains, after severe ageing, a good thermal stability and a good catalytic activity. The invention also relates to the process for preparing this mixed oxide and also to a process for treating exhaust gases from internal combustion engines using a catalyst prepared from this mixed oxide.
Mixed cerium- and zirconium-based oxide
The present invention relates to a mixed oxide of aluminium, of zirconium, of cerium, of lanthanum and optionally of at least one rare-earth metal other than cerium and lanthanum that makes it possible to prepare a catalyst that retains, after severe ageing, a good thermal stability and a good catalytic activity. The invention also relates to the process for preparing this mixed oxide and also to a process for treating exhaust gases from internal combustion engines using a catalyst prepared from this mixed oxide.
COMPOSITIONS CONTAINING ZIRCONIUM AND CERIUM AND METHODS FOR PREPARING SAME USING OXALIC ACID AND SUPERCRITICAL DRYING
Disclosed herein are compositions containing zirconium and cerium having a surprisingly small particle size. The compositions disclosed herein contain zirconium, cerium, optionally yttrium, and optionally one or more other rare earth oxides other than cerium and yttrium. The compositions exhibit a particle size characterized by a D.sub.90 value of about 5 μm to about 30 μm and a D.sub.99 value of about 5 um to about 40 um. Further disclosed are processes of producing these compositions using oxalic acid and supercritical drying in the process. The compositions can be used as a catalyst and/or part of a catalytic system. The composition is prepared by co-precipitation using oxalic acid and supercritical drying.