摘要:
An exhaust gas purification catalyst apparatus. The apparatus has a noble metal component for oxidizing NOx in an exhaust gas discharged from a diesel engine, a reducing agent spraying means for supplying the reducing agent selected from a urea component or an ammonia component, and a selective reduction catalyst (SCR) not comprising a noble metal for removing by reduction NOx by contacting with the reducing agent, in this order from the upstream side of an exhaust gas passage. Activity of the selective reduction catalyst (SCR) is maintained by setting that the noble metal component of the oxidation catalyst (DOC) comprises platinum and palladium, and ratio of platinum particles existing alone is 20% or less, or average particle diameter of the noble metal is 4 nm or larger, and by suppressing volatilization of platinum from the oxidation catalyst (DOC), even when catalyst bed temperature increases up to 900° C.
摘要:
An exhaust gas purification catalyst apparatus. The apparatus has a noble metal component for oxidizing NOx in an exhaust gas discharged from a diesel engine, a reducing agent spraying means for supplying the reducing agent selected from a urea component or an ammonia component, and a selective reduction catalyst (SCR) not comprising a noble metal for removing by reduction NOx by contacting with the reducing agent, in this order from the upstream side of an exhaust gas passage. Activity of the selective reduction catalyst (SCR) is maintained by setting that the noble metal component of the oxidation catalyst (DOC) comprises platinum and palladium, and ratio of platinum particles existing alone is 20% or less, or average particle diameter of the noble metal is 4 nm or larger, and by suppressing volatilization of platinum from the oxidation catalyst (DOC), even when catalyst bed temperature increases up to 900° C.
摘要:
An ammonia oxidation catalyst being superior in heat resistance and capable of suppressing by-production of N2O or NOx. The ammonia oxidation catalyst is made by coating at least two catalyst layers having a catalyst layer (lower layer) including a catalyst supported a noble metal on an inorganic base material including any of a composite oxide (A) having at least titania and silica as main components, alumina, and a composite oxide (B) consisting of alumina and silica; and a catalyst layer (upper layer) including a composite oxide (C) consisting of at least silica, tungsten oxide, ceria and zirconia, at the surface of an integral structure-type substrate, wherein a composition of the composite oxide (C) is silica: 20% by weight or less, tungsten oxide: 1 to 50% by weight, ceria: 1 to 60% by weight, and zirconia: 30 to 90% by weight.
摘要:
Ammonia oxidation catalyst being superior in heat resistance and capable of suppressing by-production of N2O and leakage of ammonia. The ammonia oxidation catalyst (AMOX) removes surplus ammonia, in selectively reducing nitrogen oxides by adding urea or ammonia and using a selective catalytic reduction (SCR) catalyst, into exhaust gas, wherein the ammonia oxidation catalyst is made by coating at least two catalyst layers having a catalyst layer (lower layer) including a catalyst supported a noble metal element on a composite oxide (A) having titania and silica as main components, and a catalyst layer (upper layer) including a composite oxide (C) consisting of tungsten oxide, ceria, and zirconia, at the surface of an integral structure-type substrate, wherein a composition of the composite oxide (C) is tungsten oxide: 1 to 50% by weight, ceria: 1 to 60% by weight, and zirconia: 30 to 90% by weight.
摘要:
An ammonia oxidation catalyst being superior in heat resistance and capable of suppressing by-production of N2O or NOx. The ammonia oxidation catalyst is made by coating at least two catalyst layers haying a catalyst layer (lower layer) including a catalyst supported a noble metal on an inorganic base material including any of a composite oxide (A) haying at least titania and silica as main components, alumina, and a composite oxide (B) consisting of alumina and silica; and a catalyst layer (upper layer) including a composite oxide (C) consisting of at least silica, tungsten oxide, ceria and zirconia, at the surface of an integral structure-type substrate, wherein a composition of the composite oxide (C) is silica: 20% by weight or less, tungsten oxide: 1 to 50% by weight, ceria: 1 to 60% by weight, and zirconia: 30 to 90% by weight.
摘要:
Ammonia oxidation catalyst being superior in heat resistance and capable of suppressing by-production of N2O and leakage of ammonia. The ammonia oxidation catalyst (AMOX) removes surplus ammonia, in selectively reducing nitrogen oxides by adding urea or ammonia and using a selective catalytic reduction (SCR) catalyst, into exhaust gas, wherein the ammonia oxidation catalyst is made by coating at least two catalyst layers having a catalyst layer (lower layer) including a catalyst supported a noble metal element on a composite oxide (A) having titania and silica as main components, and a catalyst layer (upper layer) including a composite oxide (C) consisting of tungsten oxide, ceria, and zirconia, at the surface of an integral structure-type substrate, wherein a composition of the composite oxide (C) is tungsten oxide: 1 to 50% by weight, ceria: 1 to 60% by weight, and zirconia: 30 to 90% by weight.
摘要:
Described are compositions and catalytic articles comprising a copper-promoted 8-ring small pore molecular sieve and an iron-promoted 8-ring small pore molecular sieve. The catalytic articles are useful in methods and systems to catalyze the reduction of nitrogen oxides in the presence of a reductant.
摘要:
An exhaust gas purification catalyst apparatus is arranged with an oxidation catalyst (DOC) having a noble metal component for oxidizing a nitrogen oxide (NO) in exhaust gas discharged from a diesel engine, a reducing agent spraying means for supplying a reducing agent selected from an urea component or an ammonia component, and a selective reduction catalyst (SCR) for reducing the nitrogen oxide (NOx) by making contacted with the reducing agent, in this order from the upstream side of a flow passage of exhaust gas. The selective reduction catalyst (SCR) does not comprise the noble metal component and includes zeolite or a crystal metal aluminophosphate; and further, a trap means for collecting the noble metal component volatilized from the oxidation catalyst (DOC) is arranged between the oxidation catalyst (DOC) and the selective reduction catalyst (SCR), or the like.
摘要:
There is provided an inorganic particle composite body comprising a layer of a substrate formed of a plastically deformable solid material and an inorganic particle layer that is composed of inorganic particles that do not plastically deform under a condition under which the solid material plastically deforms, that contains gaps defined by the inorganic particles, and that adjoins the layer of the substrate, wherein part of the solid material is in at least part of the gaps in the inorganic particle layer. This inorganic particle composite body is produced by a method including a preparation step of preparing an inorganic particle structural body comprising a layer of a substrate formed of a plastically deformable solid material and an inorganic particle layer that is composed of inorganic particles that do not plastically deform under a condition under which the solid material plastically deforms, that contains gaps defined by the inorganic particles, and that adjoins the layer of the substrate; and a filling step of plastically deforming at least part of the solid material contained in the inorganic particle structural body, thereby filling at least part of the gaps in the inorganic particle layer with part of the plastically deformed solid material.
摘要:
A method for producing an inorganic particle composite body formed of a mixture of a plastically deformable metal, and inorganic particles that do not plastically deform under a condition under which the metal plastically deforms, wherein the method comprises: a step of preparing an inorganic particles structural body that is formed of a mixture of the metal and the inorganic particles and that contains a vacant space therein, and a step of plastically deforming the metal in the structural body.