CN102006923B - Continuous diesel soot control with minimal back pressure penality using conventional flow substrates and active direct soot oxidation catalyst disposed thereon - Google Patents

Abstract

There is disclosed high cell density or tortuous/turbulent flow through monolithic catalyst devices for the direct catalytic, and (semi) continuous oxidation of diesel particulate matter. The catalysts relate to OIC/OS materials having a stable cubic crystal structure, and most especially to promoted OIC/OS wherein the promotion is achieved by the post-synthetic introduction of non-precious metals via a basic (alkaline) exchange process. The catalyst may additionally be promoted by the introduction of Precious Group Metals.

Description

Use the direct soot oxidation catalyst of activity of conventional flow substrate and configuration thereon with the continuous diesel cigarette ash control of minimum back pressure punishment

Quoting of related application

The application requires the provisional application number 61/039 of submitting on March 27th, 2008,879 rights and interests, and be the application 12/240 of submitting on September 29th, 2008,170 and be all on January 30th, 2009 submit to application 12/363,310 and 12/363,329 part continues, by all these by reference to relying on and introducing herein.

Background technology

Nearest over 30 years, introduce more and more severeer legislation and limit to regulate the discharge of gasoline and diesel engine.Referring to Regulation (EC) No715/2007 of the European Parliament and of the Council, the Official Journal of the European Union L171/1 on June 20th, 2007, also referring to Twigg, Applied Catalysis B, roll up 70 2-25 page and R.M.Heck, R.J.Farrauto Applied Catalysis A volume 221, (2001), 443-457 page and bibliography wherein.In the situation of diesel engine/compression ignition engine, this causes using diesel oxidation catalyst (DOC), catch/NOx of Diesel NOx storage catalyst (DNT/NSC) and selective catalytic reduction catalysts (SCR) to solve the gas discharging of CO, HC (DOC) and nitrogen oxide (NOx).But except this gaseous component, diesel engine discharge currents also comprises entrained solid, so-called particulate matter or cigarette ash.This carbon based substances is unburnt accessory substance and is because the inhomogeneities of the air-fuel mixture in cylinder produces, about its control be converted into eco-friendly product and proposed unique and challenge especially.Therefore, although can only pass through engine corresponding control methods (SAEPaper 2007-01-0234 before, Pfeiffer etc.) meet granular material discharged all legal requiremnts of waste gas, but be embodied in for example Euro 5 or Euro 6 (Regulation (EC) the No 715/2007 of the European Parliament and of the Council on June 20th, 2007, Official Journal of the European Union L171/1) in strict target must introduce diesel particulate filter (DPF), claim again " wall-flow filter ", can correct especially cigarette ash.

Such as, at the bottom of this DPF typically comprises the only ground mass of inertia porous ceramics (carborundum, cordierite etc.), it can be washcoated such as, to be conducive to the required chemical behavior of this device (soot combustion, the control of (secondary) emission, NOx elimination etc.) with active catalytic preparaton in addition.This washcoated preparaton heterogeneous catalysis typically itself, and can comprise the particle that distributes and be stabilized in for example, highly active noble's metal (PGM) in one or more refractory oxide (aluminium oxide).This DPF can comprise in addition oxygen and store (OS) component to improve the regeneration function of this filter.

As the result of the physical filtering of realizing by the porous wall that forces this effluent stream to pass through filter, this DPF has realized the filtration efficiency to particle.But this causes the accumulation of stored substance (so-called filter cake) in this filter along with the time, this causes owing to driving this air-flow by the back pressure more the raising punishment due to the required merit of finer and close flow restriction.This flow restriction causes the unacceptable reduction of engine performance, therefore must be by this filter cake burning to make it again to store carbonaceous particle with minimum back pressure punishment to approaching initial condition this filter " regeneration ".But, now not yet on vehicle, verify passive and continuous soot regeneration technology completely, therefore the holomorphosis of this filter needs " initiatively " or compulsory regeneration strategy; For example, referring to United States Patent (USP) 7,441,403 and United States Patent (USP) 7,313,913.These strategies initiatively depend on the manipulation of overall reaction condition of this waste gas to realize filter regeneration.Therefore, the regeneration of above-mentioned particulate filter can be by being used servicing unit to realize.For example, in the time of needs, can use and operate air fuel nozzle and igniter this waste gas and this particulate filter are heated to the required temperature of even burning of the particulate matter of being caught.Like this, the cigarette ash that this can be caught is the continuous-flow with permission waste gas from this filter surfaces burning.Alternately, can produce heat to cause this burn cycle with electric heater, for example United States Patent (USP) 7,469,532.But more generally, by so-called " injecting afterwards " this filter of circular regeneration, wherein inject by exhaust casing or introduce secondary fuel by the special fuel injection device of waste gas sequence, the hydrocarbon of carrying secretly in this waste gas streams is thus being arranged on the oxidation catalyst before this DPF and is burning to produce temporary transient heat " focusing " at this filter, and it causes that this cigarette ash is converted into eco-friendly product (CO ₂, H ₂o), for example, referring to SAE paper 2008-01-0481 and bibliography wherein.

But, use wall flow reactor to present some immediate problems to reach particle removal efficiency.First,, due to the wall stream mechanism filtering, this DPF introduces significant back pressure on this engine.And, on exposed filter, add washcoated layer and improved this back pressure, for catch the sieving actoion of cigarette ash cause back pressure further with lasting raising.As previously mentioned, any increase of back pressure is all taking engine efficiency as cost, and owing to promoting waste gas and cause by the merit of this cigarette ash filter cake, washcoated preparaton and filter consumption the lasting raising of fuel economy punishment.Therefore, making otherwise can significant back pressure/fuel economy problem in minimized trial, having spent a large amount of effort to thering is filtration efficiency but in thering is the machinery of back pressure punishment of reduction and the exploitation of heat-staple DPF and in activity that can washcoated layer load capacity realizes high conversion with minimum being washed to the exploitation of coating formulation.

In addition also still have, the outstanding problem of the regeneration cycle used about DPF.This traditional " initiatively " circulation is all energy-intensive, and causes essence and tedious waste of fuel; Be other and ongoing running cost.Therefore, in the circulation of this initiative regeneration, use the hydrocarbon component of sacrificing to apply the reduction of 5% so high fuel economy.And initiatively emission control implementation of strategies needs complicated and accurate engine management program for example, to avoid incomplete regen-eration and/or undressed discharge, United States Patent (USP) 7,412,822.In addition, the soot combustion causing by this way causes being called the phenomenon of " oil dilution ", it can adversely affect power operation and cause the dust deposit (inorganic salts) in this filter, and this can affect back pressure, cigarette ash capacity and the catalytic performance of this filter; For example United States Patent (USP) 7,433,776.Finally, should be noted that by this way the soot combustion that causes carries out and can be uncontrolled in the more even mode of (being on-catalytic).This can cause again the localized heat release " focus " of extreme temperature (1000 DEG C of T >), and it can easily damage the catalytic efficiency (surface area and the hole of PGM sintering, the de-alloy of PGM, support oxide cave in) of preparaton.In the worst situation, the catastrophic uncontrolled burning of cigarette ash can damage the only stone of this DPF by the fusing of thermal degradation or even only stone.

Therefore, carried out the degree of a lot of effort with solution or restriction and this initiative regeneration policy-related (noun) problem.The example of these effort is introduced the more passive regeneration strategy of the redox chemistry character based on the advanced OS material of use, for example US 2005/0282698A1 as attempted.In these researchs, demonstrate the reactive oxygen species that is derived from the washcoated OS material of redox active by use and can realize the temperature required reduction of soot oxidation.OS material used in this DPF is typically based on CeO ₂or other redox oxide and be not subject to the impact in the localized variation of regeneration or the air/fuel ratio of other transition events process for " buffering " this catalyst.It is by oxygen deprivation moment by active oxygen from its 3-D structure in mode " release " fast and repeatably, when occurring that excess oxygen passes through to realize from this oxygen losing of Gas Phase Adsorption " regeneration ".This activity is owing to CeO ₂pass through 2Ce ⁴⁺→ 2Ce ³⁺+ [O ^2-] reaction redox active.The high availability of this oxygen is for promoting that common oxidation/reduction chemistry is vital, for example for the CO/NO chemistry of gasoline three-way catalyst or nearer since for example, for the Direct Catalytic Oxidation of CDPF particulate matter (cigarette ash), US 2005/0282698A1, SAE 2008-01-0481 and bibliography wherein.This work is one of a lot of researchs of the chemical property of research Ce-Zr base OS material, synthetic, modification and optimization.For example, use doped with the ceria-zirconium dioxide material compared with lower valency ion and is studied widely for emission control application, for example US 6,468,941, US 6,585,944.These studies have shown that dopant ion (for example rare earth element, such as Y, La, Nd, Pr etc. compared with lower valency; Transition metal, such as Fe, Co, Cu etc. or alkaline-earth metal, for example Sr, Ca and Mg) can both there is wholesome effect to oxygen-ion conductive.This proposition is to produce by form oxygen defect in the preferred cubic fluorite lattice of this solid solution, this has reduced oxonium ion and has transferred to surperficial energy battier from crystal body, has improved thus this solid solution and be buffered in the ability of the air fuel transient phenomenon occurring in the waste gas streams of typical gasoline three-way catalyst application.

In addition show, (US 6,468,941 and US 6,585,944) use the special example of above-mentioned adulterant can provide the fully stable of this preferred cubic fluorite lattice structure for ceria-zirconium dioxide solid solution, wherein Y is identified as having the special benefit about this.The existence of this preferred cubic fluorite structure has been found that and Ce for from surface and the body of this crystal ⁴⁺→ Ce ³⁺the easiest redox chemistry relevant, therefore with body CeO ₂compare, greatly improved storage and the release capacity of oxygen.Because because the hydro-thermal extreme case existing in typical flue gas environment makes along with this material is through crystal growth/sintering, this benefit is remarkable especially.Introduce the La of Y especially and less degree and Pr and also confirmed to have limited or avoided in some cases single cubic phase ceria-zirconium dioxide disproportionation and served as reasons and be more rich in the Emission in Cubic of Ce and be more rich in the compound that the Tetragonal of Zr forms, this disproportionation is the significantly reduced process such as redox function, surface area that causes this solid solution.

Finally, United States Patent (USP) 6, 468, 941, United States Patent (USP) 6, 585, 944, U.S. Patent application 12/363, 310 and U.S. Patent application 12/363, 329 (two applications are all by reference to introducing herein) instruction (is non-noble's metal (Pt by low-priced (base) dopant metal, Pd, Rh, Au etc.)) introduce in the cubic fluorite lattice of this solid solution or the mode as an alternative of being combined with it for promoting the possibility of redox chemistry character of cerium, Fe, Ni, Co, Cu, Ag, Mn, the mixture of Bi and these elements confirms to receive publicity especially.Although therefore pass through H ₂temperature programmed reduction (Temperature Programmed Reduction, TPR) measure typical non-promotion OS material typical earth surface and reveal the redox maximum at approximately 600 DEG C, can be this temperature be reduced to 200 DEG C of > by a part that uses the cost that noble metal causes but base metal is added in this lattice.

But, although these base metals can advantageously be introduced in CeZrOx lattice and this introducing can significantly promote the low-temperature oxidation restoring function of fresh material, but the interpolation of these elements also can reduce fresh and aging phase purity and significantly reduce hydrothermal durability (promoting that crystal sintering and material are densified), causes aging loss of energy compared with not adding the base composition of base metal.In addition, in the aging cyclic process of routine, between gas phase and CeZr material, may react, this can cause the base metal element of these interpolations to be separated from this cubic fluorite lattice.This can cause again forming and has the independent body phase of lower intrinsic catalytic activity or in the poorest situation, forms and the phase of this OS or other catalytic component direct interaction, causes the directly or indirectly poisoning of this catalyst.Therefore, as of late, also need special synthetic attention can introduce guaranteeing electroneutral and maintain mutually compared with lower valency ion of promoting in this cubic fluorite structure simultaneously.Therefore, as U. S. application number 12/363, shown in 310, the synthetic phase disproportionation that causes of the OS material that comprises " doping " specific lower valency base metal promoter (Ag) in the cubic fluorite structure with about 40%Ce is to be rich in Ce and the poor region containing Ce, has significantly reduced redox property.This forms contrast with base metal (basic) switching method of recently developing having for the high activity of DPF and the suitable composition of hydrothermal durability can be provided.

Unfortunately, although carried out a large amount of effort to utilize the passive or initiative regeneration method of advanced OS material in vehicle application, before these, all met with limited success.The large quantity research of the chemical behavior occurring in these systems has been confirmed to the catalyst based activity of this OS depends on the height " contacting efficiency " between OS material and cigarette ash; For example, referring to Applied Catalysis B.Environmental 8,57, (1996).SAE paper 2008-01-0481 and U. S. application number 12/363, research subsequently described in 310 and 12/363,329 confirms that the loss of the contacting efficiency between OS and cigarette ash may be to be produced by the relevant specific chemical property of remarkable NO emissions from engines that comprises pre-EuroV legislation typical of engines now.The method has been called OS and cigarette ash " de-coupling ", and this NO that is also engine is discharged burns cigarette ash to generate the NO of CO+NO in reaction on the PGM of oxidation in being created on the direct environment of this catalyst ₂result.The NO accessory substance of the method further " circulation " is NO ₂, again cause the burning of cigarette ash, again only remove the cigarette ash directly contacting with this catalyst.This circulation is US 4,902,487 basis, and be considered to before provide the key reaction of low temperature soot combustion/regeneration.But it is only effective that this mechanism seems in the time removing the cigarette ash of low concentration and in fact only remove the cigarette ash part directly contacting with this catalyst.Therefore, this mechanism effectively " takes off this catalyst and cigarette ash coupling " and greatly reduces the usefulness of this renovation process taking OS as medium and in fact can be considered to make the passive soot regeneration of low temperature of best soot emissions control required " reality " taking OS as medium to react the reaction poisonous substance of effective " inactivation ".But, fortunately, of future generation having been found that for avoiding through the design of the OS of ion-exchange material is somebody's turn to do " de-coupling " process and promotes that the redox character of OS is all effective, therefore on engine power meter and to the vehicle of washcoated DPF, experimentally all confirmed durability benefit about soot regeneration (referring to U. S. application number 12/363,329).

Based on aforementioned need and challenge, obviously use wall stream DPF with guarantee efficient capture and subsequently the conventional method of burning particles present a lot of challenging technology barriers.Therefore, in prior art, need that combustible loss that particulate matter is simultaneously provided for regeneration with respect to traditional DPF and traditional initiative regeneration strategy reduces and about the improvement material and/or the method that cause and control the reduced complexity of any regeneration cycle for controlling and transforming.Applicant suggestion herein has the online soot combustion device of minimum/significantly reduced back pressure punishment and catalyst for the purposes at the particulate matter of carrying secretly with (partly) passive burning continuously than the needed significantly lower temperature (partly) of conventional wall flow reactor.

Summary of the invention

Can realize the marked improvement of the exploitation of the method and apparatus of the Direct Catalytic Oxidation continuous for (partly) of diesel engine particulate matter by oxygen storage (OS) material of base metal modification and the combination of conventional mobile substrate.This substrate is selected from the pottery of active washcoated layer of configuration thereon or the scope of alloying technology.This substrate can be metal parts, pottery or metal foam.This substrate is further characterized as that per unit area has a large amount of passages or micropore (cell) or because the structure of its internal flow passage is introduced the ability of turbulent flow.The direct soot oxidation catalyst of OS of this base metal modification and this circulation (flow through) solely the special combination of stone provide can be in the case of not having the synergy of high-degree of conversion particulate matter back pressure punishment that conventional DPF introduces.Especially, believe that this synergy is to be produced in the ability of lower temperature burning cigarette ash by this activity OS, it is reduced and is promoted by the thermal mass of conventional substrate again, and the latter still provides the enough geometrical surfaces for smoke deposition and reaction.This provides the larger improvement of lower temperature activity and has improved compared with conventional wall stream DPF is significant, and in conventional wall stream DPF (particularly SiC DPF), the larger thermal mass of this substrate has suppressed the initiation of soot combustion and especially its propagation.Therefore, this technical combinations provides for driving the method that effectively transforms particulate matter under the more typical condition of circulation for standard, does not rely on the soot combustion of high temperature active regeneration cycle and relative various loss and other problem.

The OS material of doping is herein based on ZrO ₂/ CeO ₂solid solution, it comprises substantially mutually pure cubic fluorite structure, and is to be prepared by the specific ion clearing house of base metal (being non-noble's metal).Be applicable to the scope of material and be described in U. S. application number 12/363,310 and 12/363,329 about the full details that carries out ion-exchange.The mode of this ion-exchange be substantially included in chemistry alkalescence (be under the condition of high pH value, namely high OH ^-/ low hydrogen ion (H ₃o ⁺) or proton (H ⁺) content) and under active metal/cation is introduced in this solid solution.As middle confirmation of working above, the material that obtains confirms that with the inactivation that wherein forms the Fast Sintering of bulk oxidation thing phase and this oxide phase and cause in fresh material be that any promotion of flooding acid metal (for example metal nitrate) realization by routine is normally compared and had high activity and hydrothermal durability.What propose passes through metal ion at Ce-ZrO _xintracell Ce ³⁺the H that defective locations place exists ⁺specific monovalence (for example K can be introduced and stablize to the exchange of component in matrix of oxide with high dispersive ⁺), divalence (for example Cu ²⁺), trivalent (for example Fe ³⁺) and the ion of higher valence state.The selection of the base metal adding be thus based on known be oxide active or that catalysis is important for be concerned about reaction.The metal of special catalysis significance comprises Ag, Cu, Co, Mn, Fe, alkali metal, alkaline-earth metal or transition metal, or other known formation can and reduce N through the decomposition subsequently under the condition within the scope of the routine operation of vehicle exhaust ₂other metal or the metalloid of stable nitrate.38 kinds of elements in the 3-12 family of this term " transition metal " expression periodic table of elements.

Also need to use high pore density/turbulent flow to circulate only stone to provide enough interactions and reaction subsequently between the soot particulates carried secretly and active catalytic coating in this waste gas streams.The high pore density of term with have a large amount of (>=600) separately the preformed of micropore flow channel/square inch circulate consistent at the bottom of only ground mass.Propose that first this high pore density introduces turbulent flow in porch so that cigarette ash and this only stone may collide maximization through the washcoated wall covering of activity.Secondly, this high pore density has limited by the stream of this only stone, has again improved the collision of particle on the washcoated layer of this activity and the possibility of stop/reaction, and has not had the large back pressure that conventional DPF is relevant to punish.And, the demixing technology (for example soot combustion catalyst in one deck (top coat) and the SCR catalyst in the second layer (lower coating)) about total washcoated layer load quantitative limitation or use with specific function has been eliminated in the use of circulation substrate, and it can use and be rich in Al equally ₂o ₃lower coating so that high washcoated layer adhesiveness to be provided, and provide low intrinsic catalysis, can disperse to comprise all required OS, PGM and NOx thereon and catch the second channel of isoreactivity component.In this second embodiment, on this, coating will present lower adhesiveness under normal operation, and conventionally will use binding agent (for example Al ₂o ₃) dilution, but the introducing of binding agent causes active reduction owing to having diluted active phase, therefore hierarchical design is preferred.This layering has been guaranteed to maximize along with its face coat that will interact/react with this cigarette ash by this circulation substrate will only be made up of and therefore will make catalytic action active material.In the time using this circulation only stone, the ability of this higher washcoated layer load capacity also provides the ability that uses the active material of higher concentration to be coated in further to improve thus in this substrate the performance of this technology and hydrothermal durability and there is no catastrophic back pressure punishment (using conventional DPF will present this phenomenon).Therefore by the use substrate of circulating, washcoated layer load capacity can be brought up to 180g/l or higher from 10g/l, improved the effective geometrical surface contacting with cigarette ash for catalyst, again to improve efficiency of combustion simultaneously.

Except using the only stone of this circulation, can also be not only for activity the structural feature (such as granularity, roughness etc.) that back pressure punishment is minimized and optimize this washcoated layer.The typical target of the normal compound agent of DPF is 5 microns or less D ₅₀(50% particle diameter) " in wall " applies (the endoporus of this substrate is applied and on the surface of this only stone, do not form discrete washcoated layer) so that back pressure punishment minimizes can carry out.This size distribution realizes by the violent grinding of raw material used in this washcoated layer typically.But, inwall is applied and uses and should " superfinishing " have been found that it is activity, stability and the surface area that is unfavorable for very much alumina component used in this OS and typical preparaton to obtain very little granularity.Result is, rate of release and total oxygen storage volume that this process can negative effect OS.In addition, this superfinishing can cause cation to be separated out and phase disproportionation for OS, due to the cationic deposition of separating out, further makes any PGM function poisoning.In contrast to this, have verified before the use of washcoated layer of high structure/roughness features is favourable (for example, referring to SAE 2005-01-1111) in triple effect application, and therefore the turbulence that can strengthen initial stream also improves the possibility that catalyst contacts with cigarette ash.Due to inviolent grinding, the maintenance of this structure also can expect that the main cigarette ash component of raising effectively contacts the possibility of OS material.The degree of close contact has shown that directly with directly soot combustion is relevant (referring to Applied Catalysis B.Environmental 8,57,1996; U. S. application number 12/363,329; SAE2008-01-0481).And, this active formulation is most important about phase, OS function or the functional integration of PGM forever, especially be the approach (be similar to and trigger match or detonator, referring to SAE2008-01-0481) that causes or propagate residue soot combustion because the energy that the burning of verified HC, CO by existing in cigarette ash material or SOF (solvable organic moiety) produces has been identified herein.

Advantages and features of the invention comprise:

A) provide the direct cigarette ash antigravity system that hydro-thermal is durable, operate (partly) continuous Direct Catalytic Oxidation for cigarette ash at relevant temperature at diesel-engine road vehicle and there is activity;

B) do not need the particle control system of DPF substrate, eliminated thus relevant substrate cost, back pressure constraint, involucrum and space requirement and the relevant accessory system of conventional DPF;

C) provide active catalyst, it provides complete oxidation function, and does not rely on the complicated conventional active regeneration circulation with associated fuel loss, filter cake formation, the possibility of catastrophic uncontrolled regeneration, oily dilution, dust deposit and the other problem relevant with conventional DPF;

D) parts through applying are about the flexibility of design of washing coating load, granularity/structure, and are therefore not only back pressure restriction and optimize the ability of washcoated layer based on performance and durability demand;

E) utilize the multilayer technique with particular functional layer other catalytic property and function to be provided by single only stone and may to realize impossible other chemical cooperated effect and the ability of feature performance benefit in the time using conventional DPF before.

F) co-operating between the washcoated layer of this activity and the substrate of high pore density is to promote Quick Oxidation cigarette ash and solvable organic moiety to avoid thus the possibility of " top layer obstruction " (having the phenomenon that the only stone of the high CPSI of routine of conventional catalyst preparaton is relevant to use).

This strategy obviously from conventional DPF system, use those are different.For this conventional design, catalysis is typically more restricted, controls from once or the NH of the CO of secondary emission, HC (SAE Paper 2007-01-0234, the people such as Pfeiffer), NOx ₃-SCR (US2008/202107-A) etc.And the design of normal compound agent restriction is significant, and typically taking main balance required between filter efficiency and maximum system back pressure as basis.

In order to meet this crew-served design object of catalyst and only stone, there are several main performance demands to meet.First, need to improve than with binary, ternary or even quaternary Ce-Zr-REOx system convention obtain the ceria reducing power at lower temperature.This reducing power is vital for the low temperature O ion obtaining from this catalyst to this cigarette ash, and this has proposed (SAE 2008-01-0481 as key reaction step; US application number 12/363,310 and 12/363,329; Appl.Catal.B vol.17,1998, p205, Appl.Catal.B vol.75,2007, p189, Catal.Today 121,2007, p237, Appl.Catal.B vol.80,2008, p248).Therefore, using containing the oxide solid solution of CeOx or CeZrOx has been general for the investigation of soot oxidation.But, conventional CeZrOx solid solution, as typically, for three-way catalyst, typical earth surface reveals redox maximum, as by the H of approximately 600 DEG C ₂it is such that temperature programmed reduction (TPR) is measured.This has applied in application as making OS material provide maximum " buffering " or oxygen to give the demand of benefit to high waste gas/reaction temperature.And this is to implementing the obstacle of CeZrOx for the direct soot oxidation of lower temperature for obtaining this activity Lattice Oxygen to the demand of high temperature.In order to solve this temperature problem, typically for example, by adding noble's metal (PGM) component (Pt, Pd or Rh) " promotion " OS material.But the promotion of these metals provides very large extra cost to the price of this off gas control system.And the interpolation of PGM (especially Pt) has promoted " typical case " chemical property of the soot oxidation taking NOx as medium, as US4, described in 902,487.But, have been found that now and know and proved that the soot oxidation taking NOx as medium is only effective on the cigarette ash of removing low concentration, and be only in fact effective in the cigarette ash part directly contacting with this catalyst, and can be considered to for the direct soot oxidation taking OS as medium is effective catalyst poison (SAE 2008-01-0481, US application number 12/363,310 and 12/363,329).Therefore in prior art, need the oxygen-ion conductive for promoting CeOx/CeZrOx base oxide material but do not use expensive PGM and do not improve the method for unfavorable result of the NOx oxidation chemistry character of this catalyst.

The second restriction, typical OS material used up to now again, is the restriction about its total oxygen storage volume, the amount of the available oxygen of being measured by TPR is typically desired lower than total Ce IV content of considering this OS material.A lot of data that can obtain up to now all meet few to only available total Ce IV process reduction of approximately 50%.At present this is due to general principle problem or because whether existing synthetic method used in the preparation of this OS material causes the restriction that mixed C e IV/CeIII valence state produces or be uncertain owing to the combination of other chemistry, structure or structure restriction.

Finally, typical OS material only provides the other synergy of limited (if there is) for emission control systems.As described elsewhere, desirable metal component provides other integrated chemical mechanism further to improve emission control, and for example NOx removes and be reduced to N ₂.

Therefore,, although OS material is to realize highly active key component, material meets and upgrades and exhaust gas catalyst of future generation that even stricter emissions object will needs presents significant restriction for exploitation.Need the OS material of newtype, its cold start-up part in lower temperature, especially vehicle application is active, to promote catalysis.These OS materials also should demonstrate high hydrothermal durability and can tolerate possible waste gas poisonous substance so that it can be used in the exhaust environment of high request of wide region.

From following detailed description, accompanying drawing and accompanying claim, those skilled in the art will recognize that and understand above-mentioned and further feature.

Brief description of the drawings

Fig. 1 has shown the schematic diagram of synthesis gas platform (SGB) reactor, has wherein implemented principle tests.Before normal experiment, only lithophysa (using the washcoated only stones of circulation of 400 or 900 micropore/square inches (CPSI)) and the quartz socket tube that is filled with quartz wool are placed in stainless steel reactor, as shown in the figure.In experimentation subsequently, use each probe of position shown in Fig. 1 to monitor temperature, pressure drop and the O of this reactor ₂content.By the overlapping on-line mass spectroscopy method with suitable correction of m/z being carried out to the representative sampling of this vapor reaction accessory substance.

In these researchs, test program used is typically made up of two stages:

Stage 1) cigarette ash loaded cycle: in this experimental section, Printex U cigarette ash analog (available from Evonik Degussa) is introduced in this reactor by use fluidized system.This fluidized bed plant comprises this cigarette ash material, N ₂therefore stream also carry the solid material of suspension by this bottom secretly to set up fluid state with this air-flow.Then by this N ₂/ cigarette ash stream mixes this reactor of merga pass with reacting air leg (gas leg), and the deposition of cigarette ash in only stone may occur herein.Cigarette ash transfer rate is 0.2g/ hour under typical loading environment.In order to keep by any cigarette ash of the only stone of this circulation, determine cigarette ash " slip-stream (slip) " or low filter efficiency, load quartzy hair bed in the exit position of this reactor.

Stage 2) regeneration: by dry N for this sample ₂purge, then at N ₂/ O ₂in (as TPO or temperature programmed oxidation) or reaction gas mixtures (as shown in Figure 3) be heated to 750 DEG C, monitoring reactor conditions, for example back pressure, O ₂content, temperature and tail gas.Notice that any cigarette ash of catching also can burn in regenerative process in quartz wool, but only at high temperature undertaken by conventional homogeneous combustion approach, this can determine again cigarette ash " slip-stream " by this only stone and therefore determine the impact of pore density on capture effect.Emphasis noticed before any performance test that by each only lithophysa, about performance/aging stablizing, this by realizing 750 DEG C of situ heat treatment for four hours herein.

In Fig. 2, show the embodiment of the regeneration test of the only stone of 900CPSI to being coated with the active catalyst described in embodiment 1 (preparing the method for Ag-OS component) and 2 (for the preparation of the method for final only stone through applying).The O in cigarette ash loading procedure of applicant's research herein ₂existence on being retained in the impact with after-combustion (catalysis is with respect to homogeneous phase) of catalyst and the secondary quartz cigarette ash in catching.Performance is roughly similar, and show the appearance of two discrete combustion incidents, once in the time of approximately 250 DEG C, owing to the direct catalysis soot combustion being produced by the good contact of cigarette ash and the washcoated layer of this activity, and in the time of 600-700 DEG C, there is being burnt by filter cake and being retained in the event for the second time of the burning of the cigarette ash in quartz wool filter of two features.This result has reflected those in SAE 2008-01-0481, and has reconfirmed the contact of catalyst-cigarette ash to there is the vital importance of direct oxidation.At O ₂consume (by O ₂sensor measure) in can see difference, it shows to exist O in loading procedure ₂be slightly favourable, this may be by O in loading procedure ₂be chemisorbed on this cigarette ash surface and realize.

Fig. 3 has summarized the various gas compositions that use in this loading and regeneration test process.Therefore, in figure subsequently, to the N that for example expression comprises listed concentration in the 3rd row that quotes of reacting gas ₂, O ₂, CO, NO and propylene gas composition.

Fig. 4 has contrasted the function of the back pressure (hereinafter claim B.P.) of only stone in three hours (10800s) cigarette ash loaded cycle response as the gaseous environment in loading procedure or temperature and gaseous environment that circulate for 400CPSI (micropore/square inch).These data show at 200 DEG C at N ₂/ O ₂and under reaction gas mixtures, load the difference clearly between cigarette ash.In the previous case, the B.P. response of this system (solely stone+quartz wool filter bed) has continuous rising, conforms to accumulation with the system deposition of cigarette ash.On the contrary, shown in accumulation cycle process and significantly raise compared with the B.P. of low rate 200 DEG C of loaded cycle under reacting gas.This is consistent with the larger reduction of concentration that is accumulated in time this intrasystem cigarette ash material, from wherein inferring that cigarette ash consumes to some extent this loaded cycle process (i.e. oxidation).For the CO in this loaded cycle process ₂release data really demonstrate for this reacting gas and are loaded with significantly higher CO ₂although supposition CO and propylene simultaneous oxidation, be only recorded as part confirmation by these data, and think that TPO (Fig. 5) is subsequently clearer and more definite.For the loaded cycle in reacting gas 250 and 300 DEG C time, the trend that the raising of B.P. reduces is even more obvious.Therefore 250 DEG C in this circulation B.P. only have little raising, and at 300 DEG C, can see that B.P. has reduced really after this initial loading cycle.Two samples are all presented at again a large amount of CO in loading procedure ₂generate, this is consistent with the continuous Direct Catalytic Oxidation of cigarette ash.

As shown in Figure 5, TPO is subsequently consistent with the B.P. response trend that (Fig. 4) sees in cigarette ash loading procedure.This is in 200 DEG C at N ₂/ O ₂in loaded cycle after TPO cause having the CO of three features ₂release profiles: at the little oxidation characteristic of 250-350 DEG C, owing to the catalytic combustion of cigarette ash; With two large CO in 700 DEG C of 640 DEG C (due to filter cake burning) and > (owing to the burning of the cigarette ash (cigarette ash that the quartz wool " filter " exporting by only stone and by orientating reaction device is caught) of " slip-stream ") ₂feature.Because this quartz wool is positioned at outside the main heating region of stove, any cigarette ash of therefore catching is therein all only at high-temp combustion, and therefore provides simple feature about the degree of cigarette ash " slip-stream ".Therefore, in this embodiment, can see at lower temperature and in the time there is no total combustion chemistry having large cigarette ash " slip-stream " by conventional 400CPSI part.This cigarette ash is assembled and is caused large B.P. as seen in Figure 4 to raise.This response can be loaded and compares with the reacting gas of 200 DEG C.In this embodiment, again there are three main CO ₂release characteristic: at the catalytic combustion of approximately 300 DEG C, burn and burn " slip-stream " of approximately 710 DEG C at the filter cakes of 650 DEG C.But, total CO ₂the large degree of output reduces, and especially, for " slip-stream " event of higher temperature, this is consistent with the continuous soot oxidation improving in loading procedure.And, due to the CO of catalytic combustion ₂significantly increase filter cake CO ₂reduce the remarkable enhancing of this reaction catalysis under simulated exhaust condition.These trend are more obvious in the loaded cycle of 250 and 300 DEG C.Both show total CO ₂the further reduction of output, the cigarette ash retaining and particularly due to the CO of cigarette ash " slip-stream " ₂minimizing.Therefore, these 300 DEG C of reacting gas load and 200 DEG C of N ₂/ O ₂the contrast loading shows CO ₂reduce > 80%, the > 80% of the cigarette ash loading in this cyclic process has burnt through continuous direct catalysis soot oxidation process.

Fig. 6 has compared the O at reactor exit in the TPO cyclic process described in Fig. 5 ₂concentration.These data have reflected trend same as described above, have recorded the O reducing for reacting gas cigarette ash loaded cycle and cigarette ash loaded cycle 250 and 300 DEG C time ₂consume.For latter two circulation, also presented approximately 475 DEG C of features of locating, its not with any special CO ₂release characteristic is relevant.This peak is owing to NO/NO ₂desorb from this catalyst, in figure below will to its more detailed research (referring to Fig. 9,11,13,14,15,16 and 18b).Note due to O ₂sensor is positioned at the exit of only stone, is not recorded to O for high temperature cigarette ash " slip-stream " event ₂consume.

In Fig. 7, record the solely impact of stone pore density (900CPSI is compared with 400CPSI) on B.P. response in cigarette ash loading procedure.Relatively show for two kinds of substrates conventionally similarly the loaded cycle of 200 DEG C, although 900CPSI part is presented at B.P. slightly higher in loaded cycle process and advances the speed, this is more consistent with the impact that cigarette ash in the more narrow passage of this substrate of expection is accumulated.

In Fig. 8, show the comparison of the follow-up TPO reaction after the loaded cycle of Fig. 7.The effect that these data show this technology significantly changes as the function of pore density.Therefore with compared with data before 400CPSI part, 900CPSI substrate demonstrates significantly improving of cigarette ash filter efficiency, only can see very little CO for filter cake and " slip-stream " combustion incident ₂release characteristic.And this sample also demonstrates the efficiency of the Direct Catalytic Oxidation feature of raising, therefore now observe the CO from Direct Catalytic Oxidation at approximately 240 DEG C ₂generate peak, be about 300-310 DEG C for the only stone of 400CPSI in contrast to this.Therefore by using the only stone of this high pore density and active washcoated layer, can reach high filter efficiency, the total CO based on 500 DEG C of T > of > 95% compared with the only stone of 400CPSI ₂output, also can realize the direct catalysis soot oxidation of continuous low temperature.

In Fig. 9, observe for compared with the only stone of 900CPSI and 400CPSI, about O ₂the comparable difference of the performance consuming.Main at 300 DEG C of O that see from 900CPSI of T < ₂consume, there is no significant O 600 DEG C of T > ₂consume.Contrary for 400CPSI finding, record the main O from filter cake oxidation at about 610-620 DEG C ₂consume.What is interesting is, all three samples have shown again approximately 475 DEG C of another feature as Fig. 6, relevant with the release of NOx from this washcoated layer.

Loading temperature is that the only stone of this 900CPSI causes the larger reduction of cigarette ash of assembling on the impact of soot accumulated TPO subsequently.Therefore, although provide the peak C O of approximately 8200 counting/s the loading of 100 DEG C ₂output, only has respectively 6000c/s and 1000c/s for the loaded cycle at 150 and 200 DEG C.And, for the loaded cycle at 150 and 200 DEG C, according to the CO without any higher temperature ₂generate peak, the sign that does not have filter cake to form.In fact by the total CO from 200 circulations on the only stone of 900CPSI ₂the integration discharging and 200 DEG C of N on the only stone of 400CPSI ₂/ O ₂circulation is compared all cigarette ashes that show the > 99% introducing in this loaded cycle process through direct catalytic combustion, and the possibility for " truly " application in kind by this technology is provided thus.

Figure 11 has shown B.P. response and the O that circulates relevant with the TPO described in Figure 10 ₂consume trace.Data set in all situations all with the CO observing ₂formation curve is consistent.Therefore, in all situations, CO ₂release/remaining soot combustion all with O ₂consume and be associated with the clean reduction of B.P., because removed restrictive soot particulates from this only stone passage.O ₂the degree consuming and clean CO ₂generation conform to, i.e. 200 DEG C of 100 > 150 >.Again, all samples has secondary NOx correlated characteristic at 475 DEG C.This B.P. response has also seemed to react the condition that cigarette ash loads, and " relaxing " response is the most sharp-pointed for 200 DEG C of circulations, is then 150 DEG C, is finally 100 DEG C of loaded cycle, again consistent with the remaining cigarette ash reservation amount of various tests.

For simulated operation condition better, under the condition that applicant changes at dynamic temperature, carry out the example of cigarette ash loaded cycle.Therefore, Figure 12 has shown the example that uses the temperature programming cigarette ash of the only stone of 900CPSI to load.In this experiment, this sample being carried out when 100 DEG C are heated to 200 DEG C full response admixture of gas to cigarette ash loaded cycle.This data show CO (and propylene) igniting (light-off) curve of expection, and it finds to meet soot combustion again, as for CO ₂generate and O ₂consume trace all see this peak then decay reflected like that.In this experiment, as all tests of carrying out in this research, in the oxidizing process of cigarette ash, do not generate CO (the correction mass spectrograph peak by m/z12 analyze determine, wherein can consider background and from CO and CO ₂the dynamic contribution to mass fragments).The overshoot (overshoot) that the continuous burning of cigarette ash also contributes to consideration to see in this thermocouple, this is found to be approximately 245 DEG C, and set point is 200 DEG C in contrast to this.

Figure 13 has shown that the temperature programming reaction cigarette ash in Figure 12 loads the temperature programming reaction experiment carrying out afterwards.The program of this test needs each standard method after completing cigarette ash loaded cycle, by being stabilized at 100 DEG C, at mobile N ₂in this sample in-situ is cooled to 100 DEG C, and then introduce full response admixture of gas, this sample is heated to 750 DEG C.This data show the expection igniting of CO, and (propylene is also through igniting, but for CO, NO and NO ₂for the purpose of trace is clear, ignore this signal), as at CO, CO ₂and O ₂it is such that response in sensor confirms.What is interesting is, again have CO at approximately 225 DEG C ₂the peak generating, then reduces, and this feature is owing to the burning that is retained in the remaining cigarette ash in this part.In this combustion incident process, the B.P. of this sample does not significantly change, and shows that the dust content retaining is so low so that do not cause any significant impact on system back pressure.Finally, there is very little CO at 475 DEG C ₂discharge this rear feature and the significant O that (referring to Fig. 9 and 11) notices in test before ₂consumption event and with NOx (NO and NO ₂) desorb event is consistent.This event is removed and releasing properties owing to the intrinsic NOx of Ag-OS material, as SAE 2008-01-0481; Described in application number 12/363,310 and 12/363,329.Therefore,, in this loaded cycle process and in temperature programming reaction subsequently, conventionally will cause any NO of the generation of catalyst-cigarette ash contact " de-coupling " ₂all be captured in the Ag of high degree of dispersion in the heart and remain into high temperature, at high temperature it is released in the plume of observing.Then the plume of this desorb NOx can react with the cigarette ash of any trace remaining in this part, particularly spatially away from any species of this catalyst surface (having " poor " contacts).

For the further temperature impact of research in reaction cigarette ash loaded cycle process, carry out other test.Figure 14 has shown the TPO result after the use reacting gas as in Figure 12 and temperature ramp loading cigarette ash for the only stone of 900CPSI.Use this TPO program but not trace that full response admixture of gas has been simplified chemical property and obtained.Therefore, in this TPO program, there is no ignition Characteristics and have a series of due to the various phenomenons of generation cause compared with temperature on this catalyst peak.First, there is CO ₂generate peak, the burning of its cigarette ash retaining owing to remnants.This peak center is at 300 DEG C, than approximately 75 DEG C of height in temperature programming response situation.The significant contribution of this exothermicity that has reflected this CO and HC igniting in the soot oxidation that promotes lower temperature.Therefore,, in reacting gas temperature ramp, along with this CO and HC take fire, it produces and has the hot focus that is enough to overcome the activation energy barrier for causing soot oxidation this only stone.Once then cause the burning of cigarette ash, produce other heat release, the heat " waterfall (cascade) " obtaining is enough to cause very high cigarette ash conversion rate, and the method relates to the method for the lower temperature soot oxidation described in US 2005/0282698A1.Soot oxidation event in this example " relaxes " relevant with very little B.P..Also see this sample desorb water, this release is relevant with the desorb of the combustion by-products from HC sample.Finally, again see the NOx desorb relevant with the removing function of Ag-OS/significantly O at 475 DEG C ₂consumption event, but do not demonstrate in this embodiment any significant relevant CO of the trace soot combustion of the contact of autodyne ₂generate.But, obviously under loading environment used, there is all the time high activity for direct soot oxidation, cause the very remaining cigarette ash of low content to be retained on the only stone of 900CPSI, reconfirm the possibility of the method for continuous direct catalysis soot oxidation.

In Figure 15, the performance of the 900CPSI only stone of research through applying in temperature programming reacting gas cigarette ash loads.The maximum temperature using is in this embodiment 500 DEG C (from 50 DEG C of intensifications).Most clearly present in this embodiment CO (and HC) igniting trace, as relevant O ₂consume the same.This CO again ₂release trace is presented at approximately 250 DEG C and increases to peak value, is then reduced to steady-state value.This is again consistent with the active catalytic burning that retains cigarette ash.Therefore, in this one side and all other sides about performance trend, the discovery before having reproduced, remove/significantly O of the NOx that is included in approximately 475 DEG C ₂consume.

Figure 16 has shown the TPO carrying out after the loaded cycle of Figure 15.Obviously do not react significantly or desorb event herein.Especially, there is no other CO ₂generate, there is no high temperature cigarette ash " slip-stream " phenomenon, these data conform to the conversion completely of any cigarette ash loading in loaded cycle process, have reconfirmed the efficient of this technology.

Next tested the impact of gas hourly space velocity on performance.Therefore, Figure 17 has compared the 15000h in standard ^-1gHSV and 25000h ^-1gHSV compare the reacting gas loaded cycle of the temperature ramp (100-200 DEG C) of (contrasting only stone volume).Emphasis is that the cigarette ash transfer rate in two tests being determined by the flow velocity by fluid bed is constant in two tests in this, and the increase of GHSV is that the flow velocity by improving each gas in reactant gas manifold is realized.Subsequently the analysis of the data from two tests is shown about the comparable response of gas chemistry character, CO (and HC) lights a fire uninfluenced, CO as comparable in this ₂it is such that response confirms.At O ₂in sensor values, have skew, may be improve because flow velocity used in high GHSV test is overall due to, but dynamic response is again identical.After completing igniting, CO ₂response has some difference, and low GHSV test shows higher clean CO ₂.Conform to therewith, the B.P. response of high GHSV shows stable rising, and this is owing to the combination of the higher clean quiet back pressure of observing due to high flow velocities and the raising of the net gathering speed of cigarette ash in this test process.Produce like this problem about cigarette ash position, be that B.P. raises be to cause due to cigarette ash " slip-stream " or the cigarette ash that is still retained in this part, and the maximum effective speed of operable smoke deposition and realize the problem of high continuous soot combustion rate.

These problems in Figure 18 a/b, are answered.It is TPO CYCLIC LOADING circulation subsequently herein.These data have shown only at lower temperature generation CO ₂, peak value is approximately 300 DEG C.Therefore even under the condition of high flow velocities, also there is no cigarette ash slip-stream, i.e. the cigarette ash of all introducings is all retained in only stone.Therefore the reduction of this soot oxidation speed, owing to the exothermic effects that the flow velocity by this part improves in loading procedure, causes clean " dilution " of this heat release waterfall, thinks that its propagation for soot combustion is vital.But as shown in the figure, " excessive " cigarette ash producing due to this process is only retained in unreacted in this part, therefore, in TPO subsequently, soot oxidation is followed the curve identical with this lower GHSV situation, only there is no clean CO ₂the raising generating.In B.P. responds, also reflected this point, the sample loading at high GHSV shows the B.P. quicker and larger than the sample loading at lower GHSV " lax (relaxation) ".Similarly, for high GHSV sample, it is larger that this NOx discharges response, reacted the better quality mark that NOx exposes in this test process.This causes again at remarkable O ₂little difference in consumption, as O ₂sensor record like that.Therefore, although conclusion is GHSV, activity is had to impact, but this impact is not catastrophic, and solely stone retains it in lower temperature burning or catches all cigarette ash the ability that also then promotes its burning at the temperature of normal operation range that is still positioned at conventional vehicles, and this system still provides effective cigarette ash to filter and burning in the situation that not relying on conventional initiative regeneration strategy.

Detailed description of the invention

The present invention relates to the method and apparatus of continuously/semicontinuous Direct Catalytic Oxidation diesel engine particulate matter for the combination by base metal modification oxygen storage (OS) material and turbulent flow/high unit intensity circulation zeolite.The special combination of the direct soot oxidation catalyst of this base metal modification OS and the only stone of this circulation provide can be in the case of the back pressure punishment that this routine DPF does not introduce the synergy of high-degree of conversion particulate matter.Applicant believes that this synergy is to be produced in the ability of the temperature combustion cigarette ash lower than legacy system by this activity OS material, it is again to be reduced and promoted by the thermal mass of conventional base, and the latter still provides the geometrical surface of enough smoke depositions and reaction.Compared with the conventional wall flow DPF (particularly for SiC DPF) of initiation and particularly its propagation of known with the large thermal mass of wherein substrate soot combustion, can significantly obtain the large improvement of lower temperature activity.

The present invention presents the marked improvement in the exploitation of the method and apparatus for (partly) continuous Direct Catalytic Oxidation diesel engine particulate matter, and it can be stored by base metal modification oxygen the combination realization of (OS) material and the conventional substrate of flowing.This substrate is selected from the pottery of active washcoated layer of configuration thereon or the scope of alloying technology.This substrate can be metal parts, pottery or metal foam.

More particularly and on the other hand, the present invention relates to for filtering at low temperatures and the catalyst of Direct Catalytic Oxidation diesel engine particulate matter and the combination of the synergy of substrate continuously.This catalyst comprises catalytic activity noble metal (Pt, Pd, Rh or its combination), main body cerium based solid solution (it is the mutually pure cubic fluorite (being measured by x Diffraction) substantially of CeZrOx type commonly known in the art) and refractory oxide (for example (γ) Al ₂o ₃, ZrO ₂or other known oxide carrier).This CeZrOx is such as, by introducing active base metal (Ag, Cu etc.) modification further, as disclosed in application number 12/363,310.At the bottom of this catalyst further comprises only ground mass of conventional design, wherein this only stone is inactive ceramic or metallic substrates, configures active catalyst preparaton/washcoated layer thereon.At the bottom of this only ground mass, be further characterized as high pore density, i.e. a large amount of active channel/unit are, for effective synergy, its value > 600 micropore/square inches.In the situation of metallic substrates, washcoated this activity layer can be applied to have beneficial effect perforation, (for example TS, LS, PE and MX type system in punching and metal forming embossing; Referring to for example United States Patent (USP) 6,689,327).

The washcoated layer of this activity and the solely combined system of stone can be applied to the challenge for the particulate emission control catalyst of (or other poor fuel) of diesel oil or (chemical dose) application that may gasoline.Particular example described herein is for interacting and the field of continuous Direct Catalytic Oxidation diesel engine particulate matter by itself and the substrate of high pore density by these materials.Due to the aforementioned synergy by the only stone of this high pore density and modification OS material production of new generation, the application has these advantages.Verified before the latter have advantage (application number 12/363,310 and 12/363,329) affect in the lower temperature regeneration of cigarette ash/be oxidized or the raising of regeneration efficiency at a lower temperature compared with the OS material of non-modification.Combine with the mobile only stone of routine of appropriate structuring now, become and can realize passive particle control catalyst completely.

Should further notice that term " first ", " second " etc. herein do not represent any order of importance, but for distinguishing a key element and another, term " one " herein does not represent number quantitative limitation, but represents to exist at least one object referring to.Further, all scopes disclosed herein all comprise end points and capable of being combined, the for example scope of " approximately 25 percentage by weights (wt%) at the most; wherein the about 20wt% of about 5wt%-is suitable; the about 15wt% of about 10wt%-is preferably " comprises end points and all medians within the scope of this, for example " the about 25wt% of about 5wt%-, the about 15wt% of about 5wt%-" etc.

About this containing cerium mixed oxide/solid-solution material synthetic, characterize and preferably the details of composition, structure, dopant content etc. refer to 12/363,310 and 12/363,329.Preferably, this solid solution comprises and has single-phase cation lattice, is measured by standard x Diffraction.More preferably, this is single-phase is cubic structure, and cubic fluorite structure is most preferred.In addition, notice that this doping method can be to carry out in the situation that not forming other body phase (by XRD determining).In numerous embodiments case, this OS material can comprise United States Patent (USP) 6,585, and those disclosed OS material in 944,6,468,941,6,387,338 and 6,605,264, introduces it again by reference to entirety.But the flexibility of this base metal exchange provides treats all at present known cerium oxides of modification thus and enhancing and the modification of Ce-Zr-base solid solution material.

So,, measured by conventional XRD method being the basic structure for cubic fluorite with the OS material preferred feature of this doping method modification.This percentage with the OS material of cubic structure is preferably greater than approximately 95% before and after exchange, is typically greater than approximately 99%, and what conventionally obtain 100% is cubic structure (the amount of the measuring technology Tetragonal based on current can not be measured) substantially.This OS material through exchange is further characterized in that storage has the large improvement of lasting redox active and the release capacity of raising (for example, by H for easy oxygen for it ₂temperature programmed reduction (TPR) method is measured).Therefore,, for the solid solution of Cu exchange, for example, observe the reduction (referring to application number 12/363,310) that Ce+Cu occurs in the temperature of approximately 350 DEG C of the low about 300-that will occur than there is no Cu adulterant in the situation that.

In exemplary embodiment, active soot oxidation catalyst comprises solid solution and the refractory oxide containing cerium oxide of one or more noble's metals (Pt, Pd, Rh and combination thereof), base metal doping, all these use making coatings together, for example be configured on inertia substrate or carrier or within, this substrate or carrier are characterized as a large amount of passages or micropore/unit are or its for introduce the ability of turbulent flow due to the structure of its internal flow passage.Emission-control equipment can comprise shell or tank member conventionally, and it can easily be connected to exhaust piping and comprise the substrate for the treatment of waste gas.This casing component can comprise outside " housing ", and its arbitrary end can be stamped funnel shaped " end cone " or smooth " end panel ", and it can comprise that permission is easily assembled to " breather pipe " on exhaust piping.Casing component can be prepared by any temperature, corrosion and lost material of meeting with in the operating process of this emission-control equipment of can bearing, such as, such as, but be not limited to ferrous metal or superfine (terrific) stainless steel (martensitic, superfine with austenitic non-corrosive material etc.).

Can in this housing, configure and keep material (" pad " or " mat "); it can bearing basement; the High Operating Temperature of this housing and this substrate is kept apart, provide substrate to keep by apply compression radial load around it, and provide surge protection for this substrate.This mat typically concentric arrangement, around this substrate, forms substrate/pad subassembly.

Can use various materials for mat and isolation.These materials can exist with forms such as pad, fiber, prefabricated components, and for example comprise following material, such as, such as, but be not limited to expanding material (comprising the material of vermiculite member, once apply the member that heat just expands), non-expansive material, ceramic material (ceramic fibre), organic binder bond, inorganic binder etc. and comprise the combination of at least one previous materials.Non-expansive material comprises for example by " 3M " Company, Minneapolis, those that Minnesota sells with trade mark " NEXTEL " and " INTERAM 1101HT " or by Unifrax Co., Niagara Falls, the material of those that New York sells with trade mark " FIBERFRAX " and " CC-MAX " etc.Expanding material comprises the Company by " 3M ", Minneapolis, the material that Minnesota sells with trade mark " INTERAM " and those expanding materials of also selling with aforementioned " FIBERFRAX " trade mark.

Above-mentioned shell is as well known to those skilled in the art and understands.

Substrate or carrier used in the present invention can comprise any materials being designed in spark ignition or Diesel engine environment, except aforementioned high pore density/turbulent flow demand, also there is following characteristics: (1) can be at approximately 600 DEG C and the temperature operation that is applied to how about 1000 DEG C for some at the most, depend on the type (for example gasoline or diesel oil) of the position of this device in waste gas system (for example menifold install, close-connected or underfloor) and this system; (2) such as can tolerate, to hydrocarbon, nitrogen oxide, carbon monoxide, particulate matter (cigarette ash etc.), CO ₂and/or the exposure of sulphur; (3) if needed, there is surface area and the structural integrity of enough supported catalysts.It is inertia that these materials impose under its condition in use.Some passable materials comprise cordierite, carborundum, metal, metal oxide (such as aluminium oxide etc.), glass etc. and the mixture that comprises at least one previous materials.Some applicable inert ceramic materials are included in can be available from NGK-Locke on market, Inc, Southfield, " the Honey Ceram " of Michigan and can be available from Corning on market, Inc., Corning, " Celcor " of New York.These materials can be (depending on this device) such as paper tinsel, prefabrication, pad, fibrous material, only stone (such as alveolate texture) etc., other loose structure (such as cellular glass, cavernous body, foam), bead, particle, molecular sieves and the form that comprises the combination (for example metal forming, perforate aluminium oxide cavernous body and porous super-low expansion glass) of at least one previous materials and form.Further, these substrates can be coated with oxide and/or hexa-aluminate, for example, be coated with the stainless steel foil of hexa-aluminate ratio.

Although this substrate can have arbitrary dimension or geometry, in the scope of aforementioned restriction, this size and geometry preferably select to optimize the surface area in given exhaust emission control device design parameter.Typically, this substrate has honeycomb-like geometry, this cellular passage has multiaspect or round-shaped, is essentially square, triangle, pentagon, hexagon, heptagon or octagon or similar geometry because easily therefore preparation and raising surface area are preferred.

This emission-control equipment can make the assembling that ins all sorts of ways.Three kinds of the method are that filling, clamshell style and strand are pressed (tourniquet) assemble method.This fill method generally includes mat is pre-assembled in to substrate around and this assembly is bored and pushed or insert in housing by filling.Fill cone as the assembling tool that can be connected to housing one end.In the position connecting, this housing and filling cone have identical cross-sectional geometry, and the length of boring along this filling, and this cross-sectional geometry narrows to larger cross-sectional geometry gradually.By this larger end, this substrate/pad subassembly can advance, and it compresses this substrate mat around, along with the advance circular cone of boring by this filling being finally pushed in housing of this assembly.

Can by comprise this emission-control equipment of solid solution through doping for exhaust treatment system so that not only active soot combustion catalyst but also NOx adsorption function to be provided, and therefore reduce especially the concentration of unfavorable component in waste gas streams.For example, as mentioned above, this OS through doping can be formed to exemplary antigravity system as catalytic component, wherein this antigravity system is configured in substrate, then substrate is configured in the enclosure.Then this substrate is configured in waste gas streams at least NOx memory function can be provided, and even reduce ideally the concentration of at least one the undesirable component wherein comprising.

According to a kind of embodiment of the present invention, this catalyst does not meet the standard construction of CDPF or Diesel NOx particle capture, and does not therefore comprise the perforated substrate with alternate channel.On the contrary, the preferable configuration of this catalyst is as the solely stone of routine " circulation " with high unit micropore counting/unit are, configures the washcoated layer of active catalyst thereon.The washcoated layer of this activity and the combination of high internal surface area and turbulent flow sedimentation mechanism are enough to promote keep under the routine operation temperature of diesel engine/compression ignition vehicle and flow and continuous particulate is oxidized.

Embodiment of the present invention are therefore:

The present invention relates to the antigravity system for the particulate matter of Direct Catalytic Oxidation exhaust gases of internal combustion engines, wherein this system comprises standard only stone device that circulates, on described standard circulates only stone device, be coated with the active oxidation catalyst preparation agent for the direct low-temperature oxidation of aforementioned particles material, wherein active catalyst contains the active oxidation reduced oxide of configuration therein.

Antigravity system as above, wherein said only stone is the only stone of circulation with > 900 micropore/square inches.

Antigravity system as above, wherein said only stone is the only stone of circulation with > 600 micropore/square inches.

Antigravity system as above, wherein said only stone is the only stone of circulation with > 400 micropore/square inches.

Antigravity system as above, wherein said only stone is the only stone of metal that can introduce turbulent flow in waste gas streams.

Antigravity system as above, wherein said only stone is metal or the ceramic foam that presents the stream of highly bending character.

Antigravity system as above, wherein this antigravity system is refractory oxides.

Antigravity system as above, wherein this antigravity system comprises cerium.

Antigravity system as above, wherein said oxide is the cerium oxide of the solid solution form of cerium and Zirconium oxide (Ce-Zr oxide).

Antigravity system as above, wherein this oxide is the cerium oxide of Ce-Zr oxide solid solution form, it is the mutually pure cubic fluorite solid solution (measuring by conventional XRD method) substantially with oxygen ion conduction character, and comprises:

A. approximately 95% zirconium at the most

B. approximately 95% cerium at the most

C. approximately 20% stabilizing agent at the most, described stabilizing agent is selected from rare earth metal, yttrium and composition thereof.

Antigravity system as above, wherein this antigravity system is the other mutually pure cubic fluorite solid solution substantially of modification by introducing one or more basic metal dopants species, and these basic metal dopants species are selected from: transition metal, alkali metal, alkaline-earth metal and IIIb family metal.

Antigravity system as above, wherein said redox oxide be by by redox active material with dissolve cationic precursor solution at high pH value/low hydrogen ion (H ₃o ⁺)/low proton (H ⁺) contact under the condition of content and the doping base metal prepared containing cerium cubic fluorite solid solution.

Antigravity system as above, wherein said base metal is to introduce by means of the ammonium hydroxide/ammino-complex of metal cation in described redox active oxide.

Antigravity system as above, wherein said base metal is to introduce in described redox oxide by means of the organic amine complex compound of metal cation.

Antigravity system as above, wherein said base metal is to introduce by means of the hydroxide compound of metal cation in described redox oxide.

Antigravity system as above, the concentration of the metal species of wherein introducing is the about 10wt% of about 0.01wt%-.

Antigravity system as above, the concentration of the metal species of wherein introducing most preferably is the about 2.5wt% of 0.1wt%-.

Antigravity system as above, the metal that wherein comprises high dispersive level doped with the solid solution of base metal, to make remaining substantially mutually pure cubic fluorite phase (> 95%) by the facies analysis of conventional XRD method, bulk metal oxide adulterant is recorded as < 5% mutually, and the dopant metal oxide granularity of measuring by spectral line broadening/Scherrer equation method is the about 100A of about 30A-.

Antigravity system as above, the metal that wherein comprises high dispersive level doped with the solid solution of base metal, to make showing that by the facies analysis of XRD the material through promoting maintains at least 95% cubic fluorite phase after 1100 DEG C of hydrothermal oxidizations are aging.

Antigravity system as above, the metal that wherein comprises high dispersive level doped with the solid solution of base metal, to make showing that by the facies analysis of XRD the material through promoting maintains at least 99% cubic fluorite phase after 1100 DEG C of hydrothermal oxidizations are aging.

For the device of Direct Catalytic Oxidation cigarette ash, comprise antigravity system as above and shell, wherein soot oxidation carries out in the temperature of approximately 650 DEG C of about 100-continuously.

Antigravity system for Direct Catalytic Oxidation cigarette ash as above, wherein not platinum group metal of this antigravity system.

Antigravity system for Direct Catalytic Oxidation cigarette ash as above, further comprises platinum group metal.

Antigravity system for Direct Catalytic Oxidation cigarette ash as above, wherein this platinum group metal is selected from: platinum, palladium, rhodium and composition thereof.

Antigravity system for Direct Catalytic Oxidation cigarette ash as above, further comprises the washcoated layer of the catalytic activity as the washcoated layer of individual layer being configured on only stone, and described washcoated layer comprises Al in addition ₂o ₃, Modification on Al ₂o ₃, SiO ₂, ZrO ₂or its combination or other applicable refractory oxides are as other carrier or binding agent.

Antigravity system for Direct Catalytic Oxidation cigarette ash as above, further comprises the washcoated layer of the catalytic activity in two or more layers being configured on only stone, and ground floor comprises Al substantially ₂o ₃, Modification on Al ₂o ₃, SiO ₂, ZrO ₂, its combination or other applicable refractory oxides be as carrier or binding agent, the second layer comprises the agent of active oxidation catalyst preparation, the agent of described active oxidation catalyst preparation comprises the mixed oxide of the base metal that adulterates.

Process the method for waste gas, comprise waste gas by antigravity system as above.

For the preparation of the method for the antigravity system for Direct Catalytic Oxidation cigarette ash as above, comprise the following steps:

By by redox active material with dissolve cationic precursor solution at high pH value/low hydrogen ion (H ₃o ⁺)/low proton (H ⁺) contact under the condition of content and prepare reduction-nitridation oxide adulterate base metal containing cerium cubic fluorite solid solution, wherein said base metal is the ammonium hydroxide/ammino-complex by means of metal cation, by means of the organic amine complex compound of metal cation, or introduce by means of the hydroxide compound of metal cation in described redox oxide.

The oxidation catalyst obtaining by method as above.

Obviously confirmed in Fig. 4-18b by using through the advantage obtaining containing the oxide of cerium and the washcoated layer of the activity of the only stone of high pore density of doping, the advantage of the redox property of the enhancing of the OS through doping wherein combining with suitable substrate causes being applicable under the condition of vehicle application direct soot combustion at a high speed.Should emphasize to observe by the base metal redox obtaining of adulterating and promote for the cation doping agent of certain limit and the OS composition of certain limit, the included data for this 2Ag-OS are only representational examples herein.

Data have herein been reacted the system research of the relevant various parameters of considering about the required target that realizes the direct catalysis soot oxidation of continuous low temperature.With reference to specific instance data, these parameters are summarized as follows the impact of performance:

A) activity of cigarette ash: the activity of cigarette ash (for example solvable organic moiety) has demonstrated in the effective performance reactive and therefore soot oxidation catalyst of determining cigarette ash has large effect (Atmos Env, vol.15 (1), 1981,91-94, SAE paper2008-01-0481, App Catal B, vol.75 (1-2), 2007, p11-16 etc.).In fact, with traditional cigarette ash TGA relatively show the T from " reality " diesel engine cigarette ash of vehicle collection for Printex Ucf. _max(temperature when maximum soot burn rate) raise approximately 50 DEG C (SAE2008-01-0481).Therefore in this research, use Printex U cigarette ash analog with special this variation of elimination from any discussion.Therefore, it is reactive equal that all particulates matter of burning in these test process can be considered to, and therefore there is no inherent variability in any data centralization providing.And the oxidation of Printex material can be considered to " worst case " scheme, the burning of the high content of graphite that its oxidation representative " is done " very much and the infusibility carbonaceous material of low SOF.Therefore, data likely have reflected the actual performance advantage that real-world application is concerned about herein.

B) gaseous environment in cigarette ash accumulation: reacting gas chemical property has remarkable impact to catalyst performance in the loaded cycle process shown in Fig. 2,4,5 and 6, and can see the properties affect regeneration of this gas atmosphere, react with temperature programming from TPO the contrast of the program of burnouting (Fig. 5,8,10,13,14,16 and 18a/b) and confirmed this point.This impact is owing to the combination of conducting heat and catalyst activates.Because a kind of heat transfer component appears in the external heat of this active catalyst by significantly the burning of the fuel element (being mainly CO and HC) of content causes in this reaction gas mixtures.This energy is retained in this washcoated layer, causes hotlyyer than the expection bed tempertaure of observing, and therefore contributes to overcome the activation energy barrier of catalysis soot oxidation.Cause activation generation the second combination of redox oxide to conduct heat and catalyst activation component from participated in CO oxidizing process by it.Shown that through the cerium oxide of doping be effective oxidation catalyst, even in the situation that there is no PGM also, and can promote the CO oxidation (DP-316440) of low temperature.Activate like this O ion transmitting function of this catalyst, released energy at the activated positions place of CO oxidation.The oxidation again subsequently of the oxygen of this consumption causes further heat release, is distributed in the total of OS, further makes in a sense OS prepare for causing soot oxidation.This mechanism has formed the part basis of US2005/0282698A1, wherein can find more complete explanation.

C) the static temperature effect in cigarette ash accumulation: obviously for the activation energy barrier that overcomes catalysis soot combustion needs heat energy/temperature.Therefore, regardless of all other factorses, the quality (Fig. 4-18b) that therefore rising of inlet temperature also reduces cigarette ash slip-stream and be retained in the cigarette ash on only stone with regard to improve the speed of catalytic oxidation simultaneously.

D) the solely effect of the pore density of stone: this is key factor of the present invention, is used higher pore density/raising micropore counting per unit area, causes the larger raising (Fig. 7-9) of catalyst performance.Therefore only by replacing the only stone of 400CPSI just to cause cigarette ash filter efficiency with the only stone of 900CPSI, (compared with 400CPSI, > 95% is based on total CO ₂, 500 DEG C of T >), avoid the large increase of the ability of cigarette ash " slip-stream " by this only stone, not because cigarette ash is by this only stone and be retained in the high temperature CO causing in quartz wool filter ₂generate, and cause the temperature required a small amount of reduction of soot combustion (it is owing to the more efficient of the washcoated layer of oxidation).The impact of pore density also has the synergy positive with temperature, observes larger clean performance gain for the only stone of 900CPSI of higher temperature than 400CPSI system.

E) effect of NOx to catalyst performance: should doped with OS material of metal low temperature remove NOx and higher temperature discharge the species that retain ability (referring to Figure 13,14,15 and 18b) be particular importance.This ability effectively make with NO ₂for " de-coupling " mechanism that the soot oxidation of medium is relevant inapplicable, this has shown to have destroyed for the close contact between direct catalysis soot oxidation required catalyst and cigarette ash (referring to SAE paper 2008-01-0481, Application No. 12/363,329).In fact by using the OS material of doping metals obviously also can use this NOx desorb plume advantageously to remove (be on space away from/leave active catalyst) trace particles material of poor contact in selected example, for example, referring to Figure 13.But, must emphasize that this is not to cause the highly active main catalytic process seen at low temperature but other small advantage.

G) the dynamic temperature effect in cigarette ash accumulation: static temperature cigarette ash loads and regeneration cycle (Fig. 4,5,7,8 and 11) and the further energy phenomenon that relatively demonstrates use the method that changes the loading of (being temperature ramp) and regeneration cycle (Figure 12,13,14 and 15) with dynamic temperature.Therefore can see that temperature in cigarette ash accumulation process raises causes the further raising of performance compared with the loading of simple static temperature be combined with the special exothermic phase of HC igniting about CO.This is called the combination of the exothermic effect of hot focus propagation owing to the applicant who described before and be explained in more detail in US 2005/0282698A1.

H) effect of GHSV and flow velocity: obviously the time of staying of particulate matter in this only stone is important factor.Therefore, it is longer that this particle rests on time in this only stone passage, also larger with the interactional possibility that is coated in the washcoated layer of activity on wall, therefore retain and the possibility of reacting higher.And, because being flowed, carries secretly particle, from Brownian collision, obtain its kinetic energy, and therefore flow velocity is higher, and the speed of this particle is just higher.This has not only reduced the time of staying in this only stone but also the state that drives subsequently laminar flow and the power of turbulent flow still less is more provided, and has reduced thus the interactional possibility of particle and wall.These hypothesis conform to the data of Figure 17,18a and 18b.In addition, flow velocity is higher, is sent to only stone energy in addition higher, because the Brownian collision increase that kinetic energy is passed to the molecule that leaves this flow channel has reduced local heat release.Therefore, GHSV is higher, and soot oxidation speed slightly reduces and causes the generation that retains cigarette ash species to increase.But under the condition of research, the insufficient flow of this raising is to cause cigarette ash " slip-stream ", prevent excessive Direct Catalytic Oxidation or in fact to prevent holomorphosis in the circulation of burnouting subsequently.Finally, should be noted that at this and burnout in circulation, the required temperature of the burning of the cigarette ash mass fraction of reservation is still significantly lower than 600 DEG C of > used in conventional DPF initiative regeneration.In fact required temperature is only still about 300-330 DEG C, i.e. easy temperature in the normal operation range of diesel vehicle.Therefore, directly the concept of catalysis soot oxidation can be used for vehicle application.

Embodiment

For the preparation of 100 grams as 2%Ag (NH used in measuring technology ₃) ₂the program of OS is as follows:

1. the 100g OS that weighs, does the correction (approximately 1.5% water) of moisture content.

2. the 3.15g silver nitrate crystal of weighing.Must the metal percentage of compensation in nitrate or solution used.Nitrate is 63.52% silver medal.

3. nitrate is dissolved in 50g deionized water.Determine the amount of water used by the water adsorption capacity of mixed oxide used.This is generally 0.5-0.5g water/gram mixed oxide.

4. by dense NH ₄oH _moisture(～30% ammonia) dropwise adds in this nitrate solution, until obtain silver two amine aqueous solutions of clarification.First solution will become brownish black, then become clarification by adding excessive ammonium hydroxide.

5. silver-colored two amine aqueous solutions are added in mixed oxide powder.Thoroughly mix to prepare the uniform moist powder of homogeneous phase and color.

6. powder is left standstill to 1 hour in room temperature.

7. in the baking oven of～110 DEG C, be dried approximately two hours or until be dried.

8. in the stove of 540 DEG C, in air, calcine 4 hours.

OS＝40％CeO ₂；50％ZrO ₂/HfO ₂；5％La ₂O ₃；5％Pr ₆O ₁₁

The program of 400 and the 900CPSI part of testing in this research for the preparation of the washcoated layer of activity and preparation is as follows: slowly add and be ground to d ₅₀be 7 microns (± 1), d ₉₀=20-25 and 100% is by the aluminium oxide of 60 microns of <.PH value is adjusted to 3.0-3.5, regulates proportion to make once then once to calcine >=1 hour by the only stone of coating and the temperature of >=540 DEG C by coating.Then by the 2Ag-OS of needs, the slurries in DI water are ground to d at the natural pH of this material ₅₀for 2+/-0.3, d ₉₀10 microns of < and 100 are by 30 microns of <.Prevent that by adding alkali pH is reduced to lower than 4.Then premixed pt nitrate and pd nitrate solution 15 minutes.In this mixture, add the sugar juice of dilution and mix minimum 30 minutes; In the initial incorporation time of 60 minutes, add Ag-OS slurries to avoid precipitated metal.In Ag-OS slurries eddy current, dropwise add PGM sugar juice.Before adding, the pH value of slurries is necessary for 5.5-6.0, and in metal adding procedure, prevents that by suitable use alkali slurries from arriving the pH value lower than 4.0.Stir two hours so that complete chemisorbed.Adjusting pH value and proportion are so that once by applying then once by applying only stone and calcining >=1 hour the temperature of >=540 DEG C.

Claims (30)

1. for the antigravity system of the particulate matter of Direct Catalytic Oxidation exhaust gases of internal combustion engines, wherein this system comprises standard only stone device that circulates, on described standard circulates only stone device, be coated with the active oxidation catalyst preparation agent for the direct low-temperature oxidation of aforementioned particles material, wherein active oxidation catalyst contains the redox active oxide of configuration therein.

2. the antigravity system of claim 1, wherein said only stone is the only stone of circulation with > 900 micropore/square inches.

3. the antigravity system of claim 1, wherein said only stone is the only stone of circulation with > 600 micropore/square inches.

4. the antigravity system of claim 1, wherein said only stone is the only stone of circulation with > 400 micropore/square inches.

5. the antigravity system of claim 1, wherein said only stone is the only stone of metal that can introduce turbulent flow in waste gas streams.

6. the antigravity system of claim 1, wherein said only stone is metal or the ceramic foam that presents the stream of highly bending character.

7. the antigravity system of aforementioned claim 1-6 any one, wherein this antigravity system is refractory oxides.

8. the antigravity system of aforementioned claim 1-6 any one, wherein this antigravity system comprises cerium.

9. the antigravity system of aforementioned claim 1-6 any one, wherein said oxide is the cerium oxide of the solid solution form of cerium and Zirconium oxide (Ce-Zr oxide).

10. the antigravity system of aforementioned claim 1-6 any one, wherein this oxide is the cerium oxide of Ce-Zr oxide solid solution form, measure by conventional XRD method, it is the mutually pure cubic fluorite solid solution substantially with oxygen ion conduction character, and comprises:

D. 95% zirconium at the most

E. 95% cerium at the most

F. 20% stabilizing agent at the most, described stabilizing agent is selected from rare earth metal and composition thereof.

The antigravity system of 11. aforementioned claim 1-6 any one, wherein this antigravity system is the other mutually pure cubic fluorite solid solution substantially of modification by introducing one or more basic metal dopants species, and these basic metal dopants species are selected from: transition metal, alkali metal and alkaline-earth metal.

The antigravity system of 12. claims 11, wherein said transition metal is IIIb family metal.

The antigravity system of any one in 13. aforementioned claim 1-6, wherein said redox active oxide be by by redox active material with dissolve cationic precursor solution at high pH value/low hydrogen ion (H ₃o ⁺)/low proton (H ⁺) contact under the condition of content and the doping base metal prepared close cerium cubic fluorite solid solution.

The antigravity system of 14. claims 13, wherein said base metal is to introduce by means of the ammonium hydroxide/ammino-complex of metal cation in described redox active oxide.

The antigravity system of 15. claims 13, wherein said base metal is to introduce in described redox active oxide by means of the organic amine complex compound of metal cation.

The antigravity system of 16. claims 13, wherein said base metal is to introduce by means of the hydroxide compound of metal cation in described redox active oxide.

The antigravity system of 17. claims 11, the concentration of the metal species of wherein introducing is 0.01wt%-10wt%.

The antigravity system of 18. claims 11, the concentration of the metal species of wherein introducing most preferably is 0.1wt%-2.5wt%.

The antigravity system of 19. claims 11, the metal that wherein comprises high dispersive level doped with the solid solution of base metal, to make remaining substantially mutually pure cubic fluorite phase by the facies analysis of conventional XRD method, wherein cubic fluorite phase > 95%, and bulk metal oxide adulterant is recorded as < 5% mutually, the dopant metal oxide granularity of measuring by spectral line broadening/Scherrer equation method is 30A-100A.

The antigravity system of 20. claims 11, the metal that wherein comprises high dispersive level doped with the solid solution of base metal, to make showing that by the facies analysis of XRD the material through promoting maintains at least 95% cubic fluorite phase after 1100 DEG C of hydrothermal oxidizations are aging.

The antigravity system of 21. claims 11, the metal that wherein comprises high dispersive level doped with the solid solution of base metal, to make showing that by the facies analysis of XRD the material through promoting maintains at least 99% cubic fluorite phase after 1100 DEG C of hydrothermal oxidizations are aging.

The antigravity system of 22. claims 1, wherein not platinum group metal of this antigravity system.

The antigravity system of 23. claims 1, wherein this antigravity system further comprises platinum group metal.

The antigravity system of 24. claims 23, wherein this platinum group metal is selected from: platinum, palladium, rhodium and composition thereof.

The antigravity system of 25. claims 23 or 24, further comprises the washcoated layer of the catalytic activity as the washcoated layer of individual layer being configured on only stone, and described washcoated layer comprises Al in addition ₂o ₃, Modification on Al ₂o ₃, SiO ₂, ZrO ₂or its combination or other applicable refractory oxides are as other carrier or binding agent.

The antigravity system of 26. claims 23 or 24, further comprises the washcoated layer of the catalytic activity in two or more layers being configured on only stone, and ground floor comprises Al substantially ₂o ₃, Modification on Al ₂o ₃, SiO ₂, ZrO ₂, its combination or other applicable refractory oxides be as carrier or binding agent, the second layer comprises the agent of active oxidation catalyst preparation, the agent of described active oxidation catalyst preparation comprises the mixed oxide of the base metal that adulterates.

27. process the method for waste gas, comprise waste gas by the antigravity system of claim 1-26 any one.

28. for the preparation of according to the method for the antigravity system of aforementioned claim 1-26 any one, comprises the following steps:

By by redox active material with dissolve cationic precursor solution at high pH value/low hydrogen ion (H ₃o ⁺)/low proton (H ⁺) contact under the condition of content and prepare reduction-nitridation oxide adulterate base metal containing cerium cubic fluorite solid solution, wherein said base metal is the ammonium hydroxide/ammino-complex by means of metal cation, by means of the organic amine complex compound of metal cation, or introduce by means of the hydroxide compound of metal cation in described redox active oxide.

The oxidation catalyst that 29. methods by claim 28 obtain.

30. devices for Direct Catalytic Oxidation cigarette ash, comprise antigravity system and the shell of aforementioned claim 1-26 any one, and wherein soot oxidation carries out the temperature of 100-650 DEG C continuously.