EP0577438A2 — Exhaust gas cleaner and method of cleaning exhaus…

Claim 1

Independent Claim 147 words

An exhaust gas cleaner for cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises a mixture of (1) a first catalyst comprising 0.1-15 weight % (on a metal basis) of a first catalytically active component consisting essentially of Ag supported by a porous inorganic oxide body; and (2) a second catalyst comprising 0.5-20 weight % (on a metal basis) of second catalytically active components supported by a porous inorganic oxide body, said second catalytically active components consisting essentially of (i) at least one alkali metal element; (ii) at least one element selected from the group consisting of Cu, Co, Mn and V; and (iii) at least one rare earth element, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body.

Claim 2

Dependent Claim 23 words

The exhaust gas cleaner according to claim 1, wherein said porous inorganic oxide body is made of alumina or a composite oxide thereof.

Claim 3

Independent Claim 207 words

A method of cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises (a) disposing an exhaust gas cleaner in a flow path of said exhaust gas, said exhaust gas cleaner comprising a mixture of (1) a first catalyst comprising 0.1-15 weight % (on a metal basis) of a first catalytically active component consisting essentially of Ag supported by a porous inorganic oxide body; and (2) a second catalyst comprising 0.5-20 weight % (on a metal basis) of second catalytically active components supported by a porous inorganic oxide body, said second catalytically active components consisting essentially of (i) at least one alkali metal element; (ii) at least one element selected from the group consisting of Cu, Co, Mn and V; and (iii) at least one rare earth element, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body; (b) introducing hydrocarbons and/or oxygen-containing organic compounds into said exhaust gas on the upstream side of said exhaust gas cleaner; and (c) bringing said exhaust gas into contact with said exhaust gas cleaner at a temperature of 200-600°C, thereby removing said nitrogen oxides.

Claim 4

Dependent Claim 150 words

An exhaust gas clcaner for cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises a cleaner substrate made of ceramics or metals, a first catalyst supported by said cleaner substrate on the exhaust gas inlet side thereof, and a second catalyst supported by said cleaner substrate on the exhaust gas outlet side thereof, wherein (1) said first catalyst comprises 0.1-15 weight % (on a metal basis) of a first catalytically active component consisting essentially of Ag supported by a porous inorganic oxide body, and (2) said second catalyst comprises 0.1-15 weight % (on a metal basis) of a second catalytically active component consisting essentially of Cu supported by a porous inorganic oxide body, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body.

Claim 5

Dependent Claim 50 words

The exhaust gas cleaner according to claim 4, wherein said second catalytically active components further contain 4 weight % or less (on a metal basis), based on said porous inorganic oxide body, of at least one element selected from the group consisting of alkali metal elements and rare earth elements.

Claim 6

Dependent Claim 23 words

The exhaust gas cleaner according to claim 4, wherein said porous inorganic oxide body is made of alumina or a composite oxide thereof.

Claim 7

Dependent Claim 23 words

The exhaust gas cleaner according to claim 5, wherein said porous inorganic oxide body is made of alumina or a composite oxide thereof.

Claim 8

Independent Claim 210 words

A method of cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises (a) disposing an exhaust gas cleaner in a flow path of said exhaust gas, said exhaust gas cleaner comprising a cleaner substrate made of ceramics or metals, a first catalyst supported by said cleaner substrate on the exhaust gas inlet side thereof, and a second catalyst supported by said cleaner substrate on the exhaust gas outlet side thereof, wherein (1) said first catalyst comprises 0.1-15 weight % (on a metal basis) of a first catalytically active component consisting essentially of Ag supported by a porous inorganic oxide body, and (2) said second catalyst comprises 0.1-15 weight % (on a metal basis) of a second catalytically active component consisting essentially of Cu supported by a porous inorganic oxide body, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body; (b) introducing hydrocarbons and/or oxygen-containing organic compounds into said exhaust gas on the upstream side of said exhaust gas cleaner; and (c) bringing said exhaust gas into contact with said exhaust gas cleaner at a temperature of 200-600°C, thereby removing said nitrogen oxides.

Claim 9

Dependent Claim 53 words

The method of cleaning an exhaust gas according to claim 8, wherein said second catalytically active components further contain 4 weight % or less (on a metal basis), based on said porous inorganic oxide body, of at least one element selected from the group consisting of alkali metal elements and rare earth elements.

Claim 10

Dependent Claim 167 words

An exhaust gas cleaner for cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises a cleaner substrate, a first catalyst supported by said cleaner substrate on the exhaust gas inlet side thereof, and a second catalyst supported by said cleaner substrate on the exhaust gas outlet side thereof, wherein (1) said first catalyst comprises 0.1-15 weight % (on a metal basis) of a first catalytically active component consisting essentially of Ag supported by a porous inorganic oxide body, and (2) said second catalyst comprises 2 weight % (on a metal basis) or less of a second catalytically active component supported by a porous inorganic oxide body, said second catalytically active component consisting essentially of at least one element selected from the group consisting of Pt, Pd, Ru, Rh and Ir, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body.

Claim 11

Dependent Claim 35 words

The exhaust gas cleaner according to claim 10, wherein said porous inorganic oxide body for said first and second catalysts is porous inorganic oxide powder coated onto said cleaner substrate made of ceramics or metals.

Claim 12

Dependent Claim 28 words

The exhaust gas cleaner according to claim 10, wherein said porous inorganic oxide body for said first and second catalysts is in the form of pellet or granule.

Claim 13

Dependent Claim 49 words

The exhaust gas cleaner according to claim 10, wherein said porous inorganic oxide body for said first catalyst is made of alumina or an alumina composite oxide, and said porous inorganic oxide body for said second catalyst is made of alumina, titania, zirconia or an a composite oxide thereof.

Claim 14

Independent Claim 234 words

A method of cleaning an exhaust gas containing nitrogen oxides, carbon monoxide, hydrocarbons and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises (a) disposing an exhaust gas cleaner in a flow path of said exhaust gas, said exhaust gas cleaner comprising a cleaner substrate, a first catalyst supported by said cleaner substrate on the exhaust gas inlet side thereof, and a second catalyst supported by said cleaner substrate on the exhaust gas outlet side thereof, wherein (1) said first catalyst comprises 0.1-15 weight % (on a metal basis) of a first catalytically active component consisting essentially of Ag supported by a porous inorganic oxide body, and (2) said second catalyst comprises 2 weight % (on a metal basis) or less of a second catalytically active component supported by a porous inorganic oxide body, said second catalytically active component consisting essentially of at least one element selected from the group consisting of Pt, Pd, Ru, Rh and Ir, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body; (b) introducing hydrocarbons and/or oxygen-containing organic compounds into said exhaust gas on the upstream side of said exhaust gas cleaner; and (c) bringing said exhaust gas into contact with said exhaust gas cleaner at a temperature of 200-600°C, thereby removing said nitrogen oxides, carbon monoxide and hydrocarbons.

Claim 15

Dependent Claim 165 words

An exhaust gas cleaner for cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises a cleaner substrate, a first catalyst supported by said cleaner substrate on the exhaust gas inlet side thereof, and a second catalyst supported by said cleaner substrate on the exhaust gas outlet side thereof, wherein (1) said first catalyst comprises 0.2-20 weight % (on a metal basis) of first catalytically active components supported by a porous inorganic oxide body, said first catalytically active components consisting essentially of Ag and at least one element selected from the group consisting of Sn, Al, Ga and In; and (2) said second catalyst comprises 0.1-15 weight % (on a metal basis) of a second catalytically active component consisting essentially of Cu supported by a porous inorganic oxide body, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body.

Claim 16

Dependent Claim 50 words

The exhaust gas cleaner according to claim 15, wherein said second catalytically active components further contain 4 weight % or less (on a metal basis), based on said porous inorganic oxide body, of at least one element selected from the group consisting of alkali metal elements and rare earth elements.

Claim 17

Dependent Claim 35 words

The exhaust gas cleaner according to claim 15, wherein said porous inorganic oxide body for said first and second catalysts is porous inorganic oxide powder coated onto said cleaner substrate made of ceramics or metals.

Claim 18

Dependent Claim 35 words

The exhaust gas cleaner according to claim 16, wherein said porous inorganic oxide body for said first and second catalysts is porous inorganic oxide powder coated onto said cleaner substrate made of ceramics or metals.

Claim 19

Dependent Claim 28 words

The exhaust gas cleaner according to claim 15, wherein said porous inorganic oxide body for said first and second catalysts is in the form of pellet or granule.

Claim 20

Dependent Claim 28 words

The exhaust gas cleaner according to claim 16 wherein said porous inorganic oxide body for said first and second catalysts is in the form of pellet or granule.

Claim 21

Dependent Claim 26 words

The exhaust gas cleaner according to claim 15, wherein said porous inorganic oxide body is made of alumina, titania, zirconia or an a composite oxide thereof.

Claim 22

Dependent Claim 26 words

The exhaust gas cleaner according to claim 16, wherein said porous inorganic oxide body is made of alumina, titania, zirconia or an a composite oxide thereof.

Claim 23

Independent Claim 225 words

A method of cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises (a) disposing an exhaust gas cleaner in a flow path of said exhaust gas, said exhaust gas cleaner comprising a cleaner substrate, a first catalyst supported by said cleaner substrate on the exhaust gas inlet side thereof, and a second catalyst supported by said cleaner substrate on the exhaust gas outlet side thereof, wherein (1) said first catalyst comprises 0.2-20 weight % (on a metal basis) of first catalytically active components supported by a porous inorganic oxide body, said first catalytically active components consisting essentially of Ag and at least one element selected from the group consisting of Sn, Al, Ga and In; and (2) said second catalyst comprises 0.1-15 weight % (on a metal basis) of a second catalytically active component consisting essentially of Cu supported by a porous inorganic oxide body, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body; (b) introducing hydrocarbons and/or oxygen-containing organic compounds into said exhaust gas on the upstream side of said exhaust gas cleaner; and (c) bringing said exhaust gas into contact with said exhaust gas cleaner at a temperature of 200-600°C, thereby removing said nitrogen oxides.

Claim 24

Dependent Claim 48 words

The method according to claim 23, wherein said second catalytically active components further contain 4 weight % or less (on a metal basis), based on said porous inorganic oxide body, of at least one element selected from the group consisting of alkali metal elements and rare earth elements.

Claim 25

Independent Claim 220 words

A method of cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises (a) disposing an exhaust gas cleaner in a flow path of said exhaust gas, said exhaust gas cleaner comprising a cleaner substrate, a first catalyst supported by said cleaner substrate on the exhaust gas inlet side thereof, and a second catalyst supported by said cleaner substrate on the exhaust gas outlet side thereof, wherein (1) said first catalyst comprises 0.2-20 weight % (on a metal basis) of first catalytically active components supported by a porous inorganic oxide body, said first catalytically active components consisting essentially of Ag and at least one element selected from the group consisting of Sn, Al, Ga and In; and (2) said second catalyst comprises 0.1-15 weight % (on a metal basis) of a second catalytically active component consisting essentially of Cu supported by a porous inorganic oxide body, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body; and (b) bringing said exhaust gas into contact with said exhaust gas cleaner at a temperature of 200-600°C, thereby causing a reaction between said nitrogen oxides and hydrocarbons remaining in said exhaust gas to remove said nitrogen oxides.

Claim 26

Dependent Claim 48 words

The method according to claim 25, wherein said second catalytically active components further contain 4 weight % or less (on a metal basis), based on said porous inorganic oxide body, of at least one element selected from the group consisting of alkali metal elements and rare earth elements.

Claim 27

Dependent Claim 91 words

An exhaust gas cleaner for cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises catalytically active components supported by a porous inorganic oxide body, said catalytically active components consisting essentially of (i) 0.1-15 weight % (on a metal basis) of Ag, and (ii) 2 weight % or less (on a metal basis) of Cu, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body.

Claim 28

Dependent Claim 23 words

The exhaust gas cleaner according to claim 27, wherein said porous inorganic oxide body is made of alumina or a composite oxide thereof.

Claim 29

Independent Claim 169 words

A method of cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises (a) disposing an exhaust gas cleaner in a flow path of said exhaust gas, said exhaust gas cleaner comprising catalytically active components supported by a porous inorganic oxide body, said catalytically active components consisting essentially of (i) 0.1-15 weight % (on a metal basis) of Ag, and (ii) 2 weight % or less (on a metal basis) of Cu, all of said percentages being based on the total amount (100 weight %) of said porous inorganic oxide body; (b) introducing 400 volume % or less, based on said nitrogen oxides in said exhaust gas, of hydrocarbons which are gaseous in a standard state into said exhaust gas on the upstream side of said exhaust gas cleaner; and (c) bringing said exhaust gas into contact with said exhaust gas cleaner at a temperature of 250-600°C, thereby removing said nitrogen oxides.

Claim 30

Dependent Claim 100 words

An exhaust gas cleaner for cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises catalytically active components supported by a porous inorganic oxide body, said catalytically active components consisting essentially of (i) 0.1-15 weight % (on a metal basis), based on said porous inorganic oxide body, of Ag, and (ii) 50 weight % or less (on a metal basis), based on said Ag, of at least one element selected from the group consisting of alkali metal elements and alkali earth metal elements.

Claim 31

Dependent Claim 23 words

The exhaust gas cleaner according to claim 30, wherein said porous inorganic oxide body is made of alumina or a composite oxide thereof.

Claim 32

Independent Claim 155 words

A method of cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises (a) disposing an exhaust gas cleaner in a flow path of said exhaust gas, said exhaust gas cleaner comprising catalytically active components supported by a porous inorganic oxide body, said catalytically active components consisting essentially of (i) 0.1-15 weight % (on a metal basis), based on said porous inorganic oxide body, of Ag, and (ii) 50 weight % or less (on a metal basis), based on said Ag, of at least one element selected from the group consisting of alkali metal elements and alkali earth metal elements; and (b) bringing said exhaust gas into contact with said exhaust gas cleaner at a temperature of 200-600°C, thereby causing a reaction between said nitrogen oxides and hydrocarbons remaining in said exhaust gas to remove said nitrogen oxides.

Claim 33

Dependent Claim 43 words

The method according to claim 32, wherein hydrocarbons and/or oxygen-containing organic compounds in amounts of 5 times or less those of said nitrogen oxides in said exhaust gas are introduced into said exhaust gas on the upstream side of said exhaust gas cleaner.

Claim 34

Dependent Claim 98 words

An exhaust gas cleaner for cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises catalytically active components supported by a porous inorganic oxide body, said catalytically active components consisting essentially of (i) 0.1-15 weight % (on a metal basis), based on said porous inorganic oxide body, of Ag, and (ii) 2 weight % or less (on a metal basis), based on said Ag, of at least one element selected from the group consisting of Pt, Pd, Ru, Rh and Ir.

Claim 35

Dependent Claim 23 words

The exhaust gas cleaner according to claim 34, wherein said porous inorganic oxide body is made of alumina or a composite oxide thereof.

Claim 36

Independent Claim 153 words

A method of cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises (a) disposing an exhaust gas cleaner in a flow path of said exhaust gas, said exhaust gas cleaner comprising catalytically active components supported by a porous inorganic oxide body, said catalytically active components consisting essentially of (i) 0.1-15 weight % (on a metal basis), based on said porous inorganic oxide body, of Ag, and (ii) 2 weight % or less (on a metal basis), based on said Ag, of at least one element selected from the group consisting of Pt, Pd, Ru, Rh and Ir; and (b) bringing said exhaust gas into contact with said exhaust gas cleaner at a temperature of 200-600°C, thereby causing a reaction between said nitrogen oxides and hydrocarbons remaining in said exhaust gas to remove said nitrogen oxides.

Claim 37

Dependent Claim 43 words

The method according to claim 36, wherein hydrocarbons and/or oxygen-containing organic compounds in amounts of 5 times or less those of said nitrogen oxides in said exhaust gas are introduced into said exhaust gas on the upstream side of said exhaust gas cleaner.

Claim 38

Dependent Claim 99 words

An exhaust gas cleaner for cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises catalytically active components supported by a porous inorganic oxide body, said catalytically active components consisting essentially of (i) 0.1-15 weight % (on a metal basis), based on said porous inorganic oxide body, of Ag, and (ii) 20 weight % or less (on a metal basis), based on said Ag, of at least one element selected from the group consisting of Mo, W, Cr, Ni, Mn and Co.

Claim 39

Dependent Claim 23 words

The exhaust gas cleaner according to claim 38, wherein said porous inorganic oxide body is made of alumina or a composite oxide thereof.

Claim 40

Independent Claim 154 words

A method of cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises (a) disposing an exhaust gas cleaner in a flow path of said exhaust gas, said exhaust gas cleaner comprising catalytically active components supported by a porous inorganic oxide body, said catalytically active components consisting essentially of (i) 0.1-15 weight % (on a metal basis), based on said porous inorganic oxide body, of Ag, and (ii) 20 weight % or less (on a metal basis), based on said Ag, of at least one element selected from the group consisting of Mo, W, Cr, Ni, Mn and Co; and (b) bringing said exhaust gas into contact with said exhaust gas cleaner at a temperature of 200-600°C, thereby causing a reaction between said nitrogen oxides and hydrocarbons remaining in said exhaust gas to remove said nitrogen oxides.

Claim 41

Dependent Claim 43 words

The method according to claim 40, wherein hydrocarbons and/or oxygen-containing organic compounds in amounts of 5 times or less those of said nitrogen oxides in said exhaust gas are introduced into said exhaust gas on the upstream side of said exhaust gas cleaner.

Claim 42

Dependent Claim 66 words

An exhaust gas cleaner for cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises catalytically active components supported by a porous inorganic oxide body, said catalytically active components consisting essentially of Ag and at least one element selected from the group consisting of Sn, Al, Ga and In.

Claim 43

Dependent Claim 23 words

The exhaust gas cleaner according to claim 42, wherein said porous inorganic oxide body is made of alumina or a composite oxide thereof.

Claim 44

Dependent Claim 32 words

The exhaust gas cleaner according to claim 42, wherein the total amount of said catalytically active components is 0.2-20 weight % (on a metal basis), based on said porous inorganic oxide body.

Claim 45

Independent Claim 121 words

A method of cleaning an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in said exhaust gas, which comprises (a) disposing an exhaust gas cleaner in a flow path of said exhaust gas, said exhaust gas cleaner comprising catalytically active components supported by a porous inorganic oxide body, said catalytically active components consisting essentially of Ag and at least one element selected from the group consisting of Sn, Al, Ga and In; and (b) bringing said exhaust gas into contact with said exhaust gas cleaner at a temperature of 200-600°C, thereby causing a reaction between said nitrogen oxides and hydrocarbons remaining in said exhaust gas to remove said nitrogen oxides.

Claim 46

Dependent Claim 41 words

The method according to claim 45, wherein hydrocarbons and/or oxygen-containing organic compounds in amounts of 0.1-5 times those of said nitrogen oxides in said exhaust gas are introduced into said exhaust gas on the upstream side of said exhaust gas cleaner.

Exhaust gas cleaner and method of cleaning exhaust gas

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