CN117643877A - Rare earth manganese zirconium compound with composite phase structure, preparation method thereof and catalyst - Google Patents
Rare earth manganese zirconium compound with composite phase structure, preparation method thereof and catalyst Download PDFInfo
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- 229910052761 rare earth metal Inorganic materials 0.000 title claims abstract description 154
- 150000002910 rare earth metals Chemical class 0.000 title claims abstract description 111
- DSGIMNDXYTYOBX-UHFFFAOYSA-N manganese zirconium Chemical compound [Mn].[Zr] DSGIMNDXYTYOBX-UHFFFAOYSA-N 0.000 title claims abstract description 78
- 239000002131 composite material Substances 0.000 title claims abstract description 64
- 239000003054 catalyst Substances 0.000 title claims abstract description 28
- 238000002360 preparation method Methods 0.000 title abstract description 24
- 239000011572 manganese Substances 0.000 claims abstract description 110
- 229910001928 zirconium oxide Inorganic materials 0.000 claims abstract description 59
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 claims abstract description 39
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 claims abstract description 39
- 229910052863 mullite Inorganic materials 0.000 claims abstract description 37
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims abstract description 31
- 150000001768 cations Chemical class 0.000 claims abstract description 30
- 150000001450 anions Chemical class 0.000 claims abstract description 21
- 239000000126 substance Substances 0.000 claims abstract description 17
- -1 rare earth zirconium oxide Chemical class 0.000 claims description 46
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 39
- 238000006243 chemical reaction Methods 0.000 claims description 39
- 239000000243 solution Substances 0.000 claims description 29
- 238000001556 precipitation Methods 0.000 claims description 28
- 238000000034 method Methods 0.000 claims description 24
- 229910002651 NO3 Inorganic materials 0.000 claims description 21
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims description 21
- 150000001875 compounds Chemical class 0.000 claims description 19
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 18
- 238000001914 filtration Methods 0.000 claims description 17
- 238000002156 mixing Methods 0.000 claims description 17
- 238000005406 washing Methods 0.000 claims description 17
- 239000012298 atmosphere Substances 0.000 claims description 15
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 14
- 229910052748 manganese Inorganic materials 0.000 claims description 14
- 239000012266 salt solution Substances 0.000 claims description 14
- 235000011121 sodium hydroxide Nutrition 0.000 claims description 13
- 238000001035 drying Methods 0.000 claims description 12
- 230000008569 process Effects 0.000 claims description 12
- 239000002243 precursor Substances 0.000 claims description 11
- 239000012267 brine Substances 0.000 claims description 10
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 claims description 10
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 claims description 9
- 238000010438 heat treatment Methods 0.000 claims description 9
- 229910052726 zirconium Inorganic materials 0.000 claims description 9
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims description 8
- 239000007800 oxidant agent Substances 0.000 claims description 7
- 229910052727 yttrium Inorganic materials 0.000 claims description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 6
- KRKNYBCHXYNGOX-UHFFFAOYSA-K Citrate Chemical compound [O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O KRKNYBCHXYNGOX-UHFFFAOYSA-K 0.000 claims description 6
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims description 6
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 6
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 6
- 229910019142 PO4 Inorganic materials 0.000 claims description 6
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 6
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- 125000000129 anionic group Chemical group 0.000 claims description 6
- 238000001354 calcination Methods 0.000 claims description 6
- 239000004202 carbamide Substances 0.000 claims description 6
- 235000013877 carbamide Nutrition 0.000 claims description 6
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 6
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 6
- 239000010452 phosphate Substances 0.000 claims description 6
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims description 5
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 claims description 5
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 5
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims description 5
- 229910052731 fluorine Inorganic materials 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims description 5
- 239000011591 potassium Substances 0.000 claims description 5
- 229910052700 potassium Inorganic materials 0.000 claims description 5
- 239000011734 sodium Substances 0.000 claims description 5
- 229910052708 sodium Inorganic materials 0.000 claims description 5
- 229910052717 sulfur Inorganic materials 0.000 claims description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 4
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 claims description 4
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 claims description 4
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 4
- 235000012538 ammonium bicarbonate Nutrition 0.000 claims description 4
- 239000001099 ammonium carbonate Substances 0.000 claims description 4
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 4
- 229910052749 magnesium Inorganic materials 0.000 claims description 4
- 239000011777 magnesium Substances 0.000 claims description 4
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 3
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 3
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 3
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 239000007864 aqueous solution Substances 0.000 claims description 3
- RCJVRSBWZCNNQT-UHFFFAOYSA-N dichloridooxygen Chemical compound ClOCl RCJVRSBWZCNNQT-UHFFFAOYSA-N 0.000 claims description 3
- MIVBAHRSNUNMPP-UHFFFAOYSA-N manganese(2+);dinitrate Chemical compound [Mn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MIVBAHRSNUNMPP-UHFFFAOYSA-N 0.000 claims description 3
- 229910052758 niobium Inorganic materials 0.000 claims description 3
- UJVRJBAUJYZFIX-UHFFFAOYSA-N nitric acid;oxozirconium Chemical compound [Zr]=O.O[N+]([O-])=O.O[N+]([O-])=O UJVRJBAUJYZFIX-UHFFFAOYSA-N 0.000 claims description 3
- 150000003961 organosilicon compounds Chemical class 0.000 claims description 3
- JRKICGRDRMAZLK-UHFFFAOYSA-L peroxydisulfate Chemical compound [O-]S(=O)(=O)OOS([O-])(=O)=O JRKICGRDRMAZLK-UHFFFAOYSA-L 0.000 claims description 3
- 150000003839 salts Chemical class 0.000 claims description 3
- 229910052706 scandium Inorganic materials 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- 239000010703 silicon Substances 0.000 claims description 3
- 239000002002 slurry Substances 0.000 claims description 3
- 229910052723 transition metal Inorganic materials 0.000 claims description 3
- 150000003624 transition metals Chemical class 0.000 claims description 3
- 229910052721 tungsten Inorganic materials 0.000 claims description 3
- 229910052720 vanadium Inorganic materials 0.000 claims description 3
- 239000000956 alloy Substances 0.000 claims description 2
- 229910045601 alloy Inorganic materials 0.000 claims description 2
- 229910021529 ammonia Inorganic materials 0.000 claims description 2
- 239000012670 alkaline solution Substances 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 claims 1
- 230000001590 oxidative effect Effects 0.000 claims 1
- 238000007254 oxidation reaction Methods 0.000 abstract description 30
- 230000003647 oxidation Effects 0.000 abstract description 29
- 230000003197 catalytic effect Effects 0.000 abstract description 27
- 229910052799 carbon Inorganic materials 0.000 abstract description 20
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 17
- 239000002245 particle Substances 0.000 abstract description 16
- 239000000463 material Substances 0.000 abstract description 11
- 239000011248 coating agent Substances 0.000 abstract description 6
- 238000000576 coating method Methods 0.000 abstract description 6
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 13
- 239000011259 mixed solution Substances 0.000 description 13
- 230000032683 aging Effects 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 12
- 239000002244 precipitate Substances 0.000 description 11
- AMWRITDGCCNYAT-UHFFFAOYSA-L manganese oxide Inorganic materials [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 239000001301 oxygen Substances 0.000 description 8
- 229910052760 oxygen Inorganic materials 0.000 description 8
- 238000003756 stirring Methods 0.000 description 8
- 239000000047 product Substances 0.000 description 7
- 230000001276 controlling effect Effects 0.000 description 6
- 238000004090 dissolution Methods 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- 229910000510 noble metal Inorganic materials 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 239000007789 gas Substances 0.000 description 4
- 239000011148 porous material Substances 0.000 description 4
- 239000011575 calcium Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910052746 lanthanum Inorganic materials 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 230000001376 precipitating effect Effects 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 230000027756 respiratory electron transport chain Effects 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 1
- 229910052688 Gadolinium Inorganic materials 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- 229910052772 Samarium Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000000026 X-ray photoelectron spectrum Methods 0.000 description 1
- 238000003916 acid precipitation Methods 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
- RCFVMJKOEJFGTM-UHFFFAOYSA-N cerium zirconium Chemical compound [Zr].[Ce] RCFVMJKOEJFGTM-UHFFFAOYSA-N 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- 150000003841 chloride salts Chemical class 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000005431 greenhouse gas Substances 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- QWDJLDTYWNBUKE-UHFFFAOYSA-L magnesium bicarbonate Chemical compound [Mg+2].OC([O-])=O.OC([O-])=O QWDJLDTYWNBUKE-UHFFFAOYSA-L 0.000 description 1
- 229910000022 magnesium bicarbonate Inorganic materials 0.000 description 1
- 235000014824 magnesium bicarbonate Nutrition 0.000 description 1
- 239000002370 magnesium bicarbonate Substances 0.000 description 1
- WWHFPJVBJUJTEA-UHFFFAOYSA-N n'-[3-chloro-4,5-bis(prop-2-ynoxy)phenyl]-n-methoxymethanimidamide Chemical compound CONC=NC1=CC(Cl)=C(OCC#C)C(OCC#C)=C1 WWHFPJVBJUJTEA-UHFFFAOYSA-N 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
Landscapes
- Catalysts (AREA)
Abstract
The invention discloses a rare earth manganese zirconium compound with a composite phase structure, a preparation method thereof and a catalyst, wherein the chemical formula of the rare earth manganese zirconium compound is RE a Mn b Zr c L d O (2‑δ) D β RE is rare earth element; l is a cation doping element, and D is an anion doping element; the composite phase structure of the rare earth manganese zirconium compound comprises: tetragonal rare earth zirconium oxide, mullite phase REMn 2 O 5 、Mn 3 O 4 Phase and Mn 2 O 3 And (3) phase (C). By having tetragonal rare earth zirconium oxide,Mullite phase REMn 2 O 5 、Mn 3 O 4 And Mn of 2 O 3 The rare earth manganese zirconium compound with the composite phase structure realizes the stable tetragonal rare earth zirconium oxide and mullite main phase structure at high temperature, does not generate perovskite phase, keeps higher NO catalytic oxidation and carbon particle oxidation performance, and meets the use requirements of DOC and DPF catalysts on high-temperature stability and high catalytic activity of coating materials.
Description
Technical Field
The invention relates to the field of supported metal catalysts, in particular to a rare earth manganese zirconium compound with a composite phase structure, a preparation method thereof and a catalyst.
Background
With the increasing lack of petroleum resources and the increasing global warming situation, lean-burn engines (diesel engines and lean-burn gasoline engines) have received a great deal of attention due to their higher fuel economy and lower greenhouse gas emissions; however, the method is thatIn the exhaust gas, a large amount of nitrogen oxides (NO x ) The CO and CH compounds not only can cause outstanding environmental problems such as photochemical smog, acid rain and the like, but also have serious harm to human health. Therefore, how to effectively remove NO in the tail gas of the lean-burn engine x Become a research hotspot for environmental catalysis today.
The post-treatment of the tail gas of the diesel engine at the present stage mainly comprises DOC, SCR, DPF, SCRF/CDPF and ASC. DOC is a diesel oxidation catalyst for reducing diesel oxides of nitrogen (NO x ) Hydrocarbon (HC) and carbon monoxide (CO) gas pollutants. Currently, DOC catalysts typically employ noble metal-supported alumina as the active ingredient, with noble metal levels typically exceeding 25g/ft 3 ，NO 2 /NO x Maximum ratio of less than 40%, in particular NO after hydrothermal ageing treatment 2 /NO x The maximum proportion is less than 35%, seriously affecting durability. NO (NO) 2 Accounting for total NO x Has smaller specific gravity and is required to increase NO 2 Specific gravity, a higher platinum group metal loading is required, thereby resulting in a significant increase in cost. Therefore, in order to obtain higher NO oxidation performance, it is necessary to add a catalytic material having high catalytic activity for NO and high thermal stability under high temperature conditions to achieve the effects of reducing the amount of platinum group metal used and increasing the NO oxidation rate. Patent cn201310571863.X discloses a mullite structure material, which has a higher catalytic oxidation rate to NO at low temperature, but the mullite structure material is generally unstable at high temperature and is easy to decompose into a perovskite structure, so that the catalytic oxidation rate is rapidly reduced, and industrial application is difficult.
DPFs are particle traps that act to trap carbon particles, and to increase passive regeneration capacity, a noble metal-containing coating is typically applied to the DPF to reduce the carbon particle conversion temperature, but currently carbon conversion temperatures are greater than 350 ℃, and the use of noble metals increases costs. Patent CN101733111B discloses a perovskite/ceria composite catalyst, the conversion temperature of carbon particles is 354 ℃ at the minimum, and the catalytic capability equivalent to that of noble metals can be achieved, but the conversion temperature needs to be further reduced to reduce the oil consumption.
Disclosure of Invention
Embodiments of the inventionAims to provide a composite phase structure rare earth manganese zirconium compound, a preparation method thereof and a catalyst, wherein the composite phase structure rare earth manganese zirconium compound comprises tetragonal rare earth zirconium oxide and mullite phase REMn 2 O 5 、Mn 3 O 4 And Mn of 2 O 3 Rare earth manganese zirconium compound with composite phase structure, and tetragonal rare earth zirconium oxide and mullite REMn which are stable at high temperature are realized 2 O 5 The main phase structure does not generate perovskite phase, and the purpose of maintaining higher NO catalytic oxidation and carbon particle oxidation performance is achieved, so that the use requirements of DOC and DPF catalysts on high-temperature stability and high catalytic activity of coating materials are met.
To solve the above technical problems, a first aspect of the embodiments of the present invention provides a rare earth manganese zirconium compound with a composite phase structure, where the rare earth manganese zirconium compound has a chemical formula of RE a Mn b Zr c L d O (2-δ) D β RE is rare earth element; l is a cation doping element, and D is an anion doping element;
wherein, in terms of mole number, a is more than or equal to 0.10 and less than or equal to 0.50,0.09, b is more than or equal to 0.40,0.20 and less than or equal to 0.80,0, d is more than or equal to 0.40,0 and less than or equal to 0.30,0, beta is more than or equal to 0.10, and a+b+c+d=1;
the composite phase structure of the rare earth manganese zirconium compound comprises: tetragonal rare earth zirconium oxide, mullite phase REMn 2 O 5 、Mn 3 O 4 Phase and Mn 2 O 3 And (3) phase (C).
Further, the mole content of the tetragonal phase rare earth zirconium oxide is 60.0% -95.0%, and the mullite phase REMn 2 O 5 The molar content of (2) is 3.0-30.0%, and the Mn is as follows 2 O 3 The molar content of the phase is 0.1-5.0%, mn 3 O 4 The molar content of the phase is 0.1 to 5.0 percent;
preferably, the mole content of the tetragonal rare earth zirconium oxide is 70.0-90.0%, and the mullite phase REMn 2 O 5 The molar content of (2) is 5.0-25.0%, and the Mn is as follows 2 O 3 The molar content of the phase is 0.5-2.0%, mn 3 O 4 The molar content of the phases is 0.5% -2.0%.
Further, the manganese in the rare earth manganese zirconium compound includes: trivalent Mn and tetravalent Mn, wherein the mole ratio of the trivalent Mn to the tetravalent Mn on the surface is 0.8:1-5.0:1;
preferably, the molar ratio of trivalent Mn to tetravalent Mn of the surface is in the range of 0.9:1 to 2.5:1.
Further, the cation doping element L includes: alkaline earth metals, transition metals, aluminum or silicon, present in the cerium-zirconium tetragonal phase rare earth zirconium oxide and/or in the mullite phase REMn 2 O 5 In (a) and (b);
the anion doping element D includes: at least one of anions N, P, F and S is present in the tetragonal rare earth zirconium oxide, the mullite phase REMn 2 O 5 Mn of the alloy 3 O 4 Phases and Mn 2 O 3 At least one of the phases;
the morphology of the cation doping element L and the anion doping element D in the rare earth manganese zirconium compound includes at least one of an oxide, a nitrogen-containing compound, a fluoride, a phosphate, and a sulfate.
Further, the cation doping element L includes: at least one of Al, si, ga, ge, in, hf, ba, sr, mg, ca, fe, co, ni, cu, zn, V, ti, cr, mo, W, sn and Nb;
the anion doping element D includes: at least one of anions N, P, F and S.
Further, the RE includes: la, ce, pr, nd, sm, eu, gd, tb, dy, ho, er, tm, yb, lu, Y and Sc;
preferably, the RE includes: la, ce, pr, nd, sm, eu, gd and Y.
Correspondingly, a second aspect of the embodiment of the invention provides a preparation method of a rare earth manganese zirconium compound with a composite phase structure, which is used for preparing the rare earth manganese zirconium compound with the composite phase structure, and comprises the following steps:
s1, mixing all zirconium, all or part of RE and all or part of salt solution of cation doping element L, adding alkaline substances for precipitation reaction, and filtering, washing, drying and roasting to obtain RE-L-containing rare earth zirconium oxide;
s2, mixing all manganese, the rest RE and the rest salt solution of the cation doping element L with the rare earth zirconium oxide obtained in the S1 to obtain a compound precursor;
and S3, performing heat treatment on the composite compound precursor obtained in the step S2, and calcining under a preset atmosphere to obtain the composite-phase rare earth manganese zirconium compound.
Further, the preparation method of the rare earth manganese zirconium compound with the composite phase structure further comprises the following steps:
in the step S2, the mixed salt solution of all manganese, the rest RE and the rest cation doping element L is mixed with the rare earth zirconium oxide obtained in the step S1, alkaline substances and oxidizing agents are added at the same time, the mixture is reacted to obtain composite compound slurry, and the composite compound precursor is obtained after filtering and washing.
Further, the preparation method of the rare earth manganese zirconium compound with the composite phase structure further comprises the following steps:
the anionic doping element D is added at the same time as the mixed salt solution is prepared in step S1 and/or step S2.
Further, the manganese source in the mixed brine solution includes: at least one of chloride, nitrate, sulfate and acetate, preferably manganese nitrate;
the zirconium source in the mixed brine solution comprises: at least one of oxychloride, nitrate, sulfate, acetate and citrate, preferably zirconyl nitrate;
the brine solution containing the cation doping elements L and RE includes: a molten salt or aqueous solution of at least one of a chloride, nitrate, sulfate, acetate, citrate, amino acid salt, organosilicon compound, preferably nitrate;
the alkaline substance includes: at least one of urea, hydroxide, ammonia, carbonate, and bicarbonate, the bicarbonate comprising: at least one of ammonium, potassium, sodium and magnesium elements, wherein the hydroxide comprises at least one of ammonium, sodium, potassium and magnesium elements, and preferably, the alkaline substance comprises: at least one of sodium hydroxide, urea, ammonia water and ammonium bicarbonate;
the roasting is carried out in a preset atmosphere which comprises air, CO and N 2 Or H 2 One or two of the following components;
the oxidizing agent comprises: at least one of hydrogen peroxide, persulfate, air, and ozone;
the anion doping element D includes: at least one of nitrate, fluoride, phosphate and sulfate; preferably, the anion doping element D includes: nitrate and/or sulfate.
Further, the pH value in the precipitation process is controlled to be 4.5-14, preferably 5-11;
the pH value of the precipitation end point is controlled to be 8-13, preferably 9-11;
the temperature during the precipitation is 0 ℃ to 120 ℃, preferably 20 ℃ to 80 ℃.
Further, the roasting condition of the rare earth zirconium oxide is kept for 1 to 20 hours within the range of 500 to 1000 ℃; preferably, the temperature is kept within the range of 600-900 ℃ for 2-10 h;
the heat treatment temperature is 100-500 ℃ and the time is 2-30 hours; preferably, the heat treatment temperature is 150-300 ℃ and the time is 6-12 h;
the calcination condition is kept for 1 to 20 hours within the range of 400 to 1000 ℃; preferably at 500-800 deg.C for 3-10 h.
Accordingly, a third aspect of the embodiments of the present invention provides a catalyst comprising the above-described composite phase structured rare earth manganese zirconium compound.
The technical scheme provided by the embodiment of the invention has the following beneficial technical effects:
the rare earth zirconium oxide with tetragonal phase and the mullite phase REMn are constructed by fractional precipitation and atmosphere roasting control 2 O 5 、Mn 3 O 4 And Mn of 2 O 3 Rare earth manganese zirconium compound with composite phase structure and mullite phase REMn 2 O 5 The interaction with tetragonal rare earth zirconium oxide can increase the oxygen defect concentration and improve the thermal stability of the material. Small amount of Mn 3 O 4 And Mn of 2 O 3 The method can improve the electron transfer capability between Mn and Mn of a composite phase, improve the transfer rate of active oxygen, improve the adsorption capability to NO, be favorable for generating intermediate species such as bidentate nitrate, bridge nitrate and the like, and lead the adsorption capability to be moderate, thereby reducing the NO oxidation reaction energy barrier, achieving the purpose of keeping higher NO catalytic oxidation performance, and meeting the use requirements of DOC and DPF catalysts on high-temperature stability and high catalytic activity of coating materials.
Drawings
FIG. 1 is a flow chart of a preparation method of a rare earth manganese zirconium compound with a composite phase structure provided by the embodiment of the invention.
Fig. 2 is an XRD pattern of a rare earth manganese zirconium compound of a composite phase structure provided in the embodiment of the present invention.
Detailed Description
The objects, technical solutions and advantages of the present invention will become more apparent by the following detailed description of the present invention with reference to the accompanying drawings. It should be understood that the description is only illustrative and is not intended to limit the scope of the invention. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the present invention.
In a first aspect, the embodiment of the invention provides a rare earth manganese zirconium compound with a composite phase structure, wherein the chemical formula of the rare earth manganese zirconium compound is RE a Mn b Zr c L d O (2-δ) D β RE is rare earth element; l is a cation doping element, and D is an anion doping element; wherein, in terms of mole number, a is more than or equal to 0.10 and less than or equal to 0.50,0.09, b is more than or equal to 0.40,0.20 and less than or equal to 0.80,0, d is more than or equal to 0.40,0 and less than or equal to 0.30,0, beta is more than or equal to 0.10, and a+b+c+d=1; the composite phase structure of the rare earth manganese zirconium compound comprises: tetragonal rare earth zirconium oxide, mullite phase REMn 2 O 5 、Mn 3 O 4 Phase and Mn 2 O 3 And (3) phase (C).
Aiming at the oxidation performance and the high-temperature thermal stability of the prior DOC catalyst, the catalyst needs to be further improvedThe invention relates to a method for improving the technical requirements of DPF carbon conversion temperature reduction and further reducing noble metal consumption, which is characterized by comprising tetragonal rare earth zirconium oxide and mullite phase REMn 2 O 5 、Mn 3 O 4 And Mn of 2 O 3 Rare earth manganese zirconium compound with composite phase structure, and tetragonal rare earth zirconium oxide and mullite REMn which are stable at high temperature are realized 2 O 5 The main phase structure does not generate perovskite phase, and the composite phase structure can improve the electron transfer capability between Mn and Mn, improve the transfer rate of active oxygen, realize the purpose of keeping higher NO catalytic oxidation and carbon particle oxidation performance, and meet the use requirements of DOC and DPF catalysts on high-temperature stability and high catalytic activity of coating materials.
Further, the composite phase structure of the rare earth manganese zirconium compound is tetragonal phase rare earth zirconium oxide and mullite phase REMn 2 O 5 、Mn 3 O 4 And Mn of 2 O 3 The ratio corresponds to the firing atmosphere and/or the oxidizing agent. The mol content of tetragonal rare earth zirconium oxide is 60.0% -95.0%, mullite phase REMn 2 O 5 The molar content of (3.0) - (30.0%), mn 2 O 3 The mole content of the phase is 0.1-5.0%, mn 3 O 4 The molar content of the phase is 0.1 to 5.0 percent; preferably, the mole content of tetragonal rare earth zirconium oxide is 70.0% -90.0%, mullite phase REMn 2 O 5 The molar content of (2) is 5.0-25.0%, mn 2 O 3 The mole content of the phase is 0.5-2.0%, mn 3 O 4 The molar content of the phases is 0.5% -2.0%.
Further, the manganese in the rare earth manganese zirconium compound includes: trivalent Mn and tetravalent Mn, wherein the mole ratio of the trivalent Mn to the tetravalent Mn on the surface is 0.8:1-5.0:1; preferably, the molar ratio of trivalent Mn to tetravalent Mn of the surface is in the range of 0.9:1 to 2.5:1.
Specifically, the molar ratio of trivalent Mn to tetravalent Mn was detected using XPS. By subjecting the spectral peak of Mn 2p to Gaussian fitting peak separation, in XPS spectrum, the peak signal with electron binding energy around 641.3eV is attributed to trivalent Mn (Mn 3+ ) Near 642.5eV is tetravalent Mn (Mn 4+ ) Characteristic signal of Mn 3+ Corresponding peak area and Mn 4+ The molar ratio of trivalent Mn to tetravalent Mn is calculated as the ratio of the corresponding peak areas.
Further, the cation doping element L includes: alkaline earth metals, transition metals, aluminum or silicon, present in tetragonal rare earth zirconium oxides and/or mullite phases REMn 2 O 5 The phase of (a); the anion doping element D exists in tetragonal rare earth zirconium oxide and mullite phase REMn 2 O 5 、Mn 3 O 4 Phase and Mn 2 O 3 At least one of the phases; the morphology of the cation-doped element L and the anion-doped element D in the rare earth manganese zirconium compound includes at least one of an oxide, a nitrogen-containing compound, a fluoride, a phosphate, and a sulfate.
Further, the cation doping element L includes: at least one of Al, si, ga, ge, in, hf, ba, sr, mg, ca, fe, co, ni, cu, zn, V, ti, cr, mo, W, sn and Nb; the anionic doping element D includes: at least one of anions N, P, F and S.
Further, RE comprises at least one of La, ce, pr, nd, sm, eu, gd, tb, dy, ho, er, tm, yb, lu, Y and Sc; preferably, RE is at least one of La, ce, pr, nd, sm, eu, gd and Y.
The rare earth manganese zirconium compound with the composite phase structure has specific surface area more than or equal to 40m 2 Per gram, further, the specific surface area is more than or equal to 45m 2 And/g. The compound has pore diameter of 5-30nm and pore volume of more than or equal to 0.10ml/g; further, the pore diameter is 8-20nm, and the pore volume is more than or equal to 0.20ml/g. 750 ℃,10% H 2 After O10 h aging treatment, the rare earth manganese zirconium composite compound with the composite phase structure still has 4 phases, and comprises tetragonal rare earth zirconium oxide and mullite phase REMn 2 O 5 、Mn 3 O 4 Mn and Mn 2 O 3 And (3) phase (C).
Accordingly, referring to fig. 1, a second aspect of the embodiment of the present invention provides a method for preparing a rare earth manganese zirconium compound with a composite phase structure, which is used for preparing the rare earth manganese zirconium compound with the composite phase structure, and includes the following steps:
step S1, mixing all zirconium, all or part RE and all or part of salt solution of cation doping element L, adding alkaline substances for precipitation reaction, and filtering, washing, drying and roasting to obtain RE-L-containing rare earth zirconium oxide.
And S2, mixing the total manganese, the rest RE and the rest salt solution of the cation doping element L with the rare earth zirconium oxide obtained in the step S1 to obtain a compound precursor.
And S3, performing heat treatment on the composite compound precursor obtained in the step S2 and calcining the composite compound precursor in a preset atmosphere to obtain the composite-phase rare earth manganese zirconium compound.
In a specific embodiment of the invention, the preparation method of the rare earth manganese zirconium compound with the composite phase structure in the invention also comprises the steps of mixing the mixed salt solution of all manganese, the rest RE and the rest cation doping element L with the rare earth zirconium oxide obtained in the step S1, adding alkaline substances and oxidizing agents at the same time, reacting to obtain composite compound slurry, filtering and washing to obtain the composite compound precursor.
In another embodiment of the invention, the anionic doping element D may also be added at the same time as the preparation of the mixed brine solution in step S1 and/or step S2.
Optionally, the source of manganese in the mixed brine solution includes: at least one of chloride, nitrate, sulfate and acetate, preferably manganese nitrate.
Optionally, the source of zirconium in the mixed brine solution includes: at least one of oxychloride, nitrate, sulfate, acetate and citrate is preferably zirconyl nitrate.
Optionally, the brine solution comprising the cation doping element M, the cation doping element L and RE comprises: a molten salt or aqueous solution of at least one of a chloride, nitrate, sulfate, acetate, citrate and amino acid salt, and an organosilicon compound, preferably nitrate.
Optionally, the alkaline substance includes: at least one of hydroxide, carbonate or bicarbonate of at least one element of magnesium bicarbonate, urea, and ammonium, sodium, and potassium; preferably, the alkaline substance includes: at least one of sodium hydroxide, urea, ammonia water and ammonium bicarbonate.
Optionally, the anionic doping element D includes: at least one of nitrate, fluoride, phosphate and sulfate; preferably, the anionic doping element D comprises: nitrate and/or sulfate.
Optionally, the roasting is performed in a preset atmosphere comprising one or two of air, CO, N2 and H2.
Optionally, the oxidizing agent comprises: at least one of hydrogen peroxide, persulfate, air, and ozone.
Further, the pH value in the precipitation process is controlled to be 4.5-14, preferably 5-11; the pH value of the precipitation end point is controlled to be 8-13, preferably 9-11; the temperature during precipitation is from 0℃to 120℃and preferably from 20℃to 80 ℃.
Further, the roasting condition of the rare earth zirconium oxide is kept for 1 to 20 hours within the range of 500 to 1000 ℃; preferably, the temperature is kept within the range of 600-900 ℃ for 2-10 h; the heat treatment temperature is 100-500 ℃ and the time is 2-30 h; preferably, the heat treatment temperature is 150-300 ℃ and the time is 6-12 h; the calcination condition is kept for 1 to 20 hours at the temperature of between 400 and 1000 ℃; preferably at 500-800 deg.C for 3-10 h.
The preparation process of the rare earth manganese zirconium compound with a composite phase structure is specifically described below in comparative examples and examples of several preparation methods:
comparative example 1:
according to La 0.05 Y 0.05 Ce 0.1 Zr 0.75 Hf 0.05 O 2 The molar ratio of La/Y/Zr/Hf in the rare earth zirconium oxide is proportioned to obtain a mixed solution with the total cation concentration of 1.5M; under the condition of stirring, uniformly and quickly adding the mixed feed liquid into 3.0M NaOH solution, wherein the pH value in the precipitation process is 10-14, the end point pH value is 10, and the temperature is controlled to be 50 ℃; filtering, washing and drying the precipitate, and roasting at 650 ℃ for 8 hours to obtain tetragonal rare earth zirconium oxide La 0.05 Y 0.05 Ce 0.1 Zr 0.8 O 2 。
After the rare earth zirconium oxide obtained by the preparation method of the comparative example 1 is subjected to hydrothermal aging at 750 ℃ for 10 hours, the highest conversion rate of the catalytic oxidation NO is 13%, and the conversion temperature corresponding to the highest conversion rate is 450 ℃.
Comparative example 2:
according to YMn 2 O 5 Mixing the rare earth manganese oxide with the molar ratio of Y/Mn to obtain a mixed solution with the total concentration of cations of 1.2M; adding the mixed solution and 2.8M NaOH solution into a reactor at uniform speed under stirring, precipitating at pH 9+ -0.2, end-point pH 9, controlling temperature to 40deg.C, adding Mn and alkali 2+ Equimolar amount of H 2 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Filtering, washing and drying the precipitate, and roasting at 820 ℃ for 8 hours to obtain rare earth manganese oxide YMn of mullite phase 2 O 5 。
After the rare earth manganese oxide obtained by the preparation method of the comparative example 2 is subjected to hydrothermal aging at 750 ℃ for 10 hours, the highest conversion rate of the catalytic oxidation NO is 35%, and the conversion temperature corresponding to the highest conversion rate is 372 ℃. Fresh catalyst is used for catalyzing carbon particles to oxidize CO at a temperature of 405 ℃ and a temperature of T50 2 The selectivity was 83.6%.
Comparative example 3:
according to Sm 0.32 Mn 0.68 O 1.79 Mixing the materials according to the Sm/Mn molar ratio in the rare earth manganese oxide to obtain a mixed solution with the total cation concentration of 1.0M; under the condition of stirring, uniformly and quickly adding the mixed feed liquid into 2.0M ammonia water solution, wherein the pH value in the precipitation process is 5-9, the final pH value is 8.9, and the temperature is controlled to be 60 ℃; filtering, washing and drying the precipitate, and roasting for 8 hours at 830 ℃ to obtain a mullite phase and Mn-containing phase 2 O 3 Rare earth manganese oxide Sm of phase 0.32 Mn 0.68 O 1.79 。
After the rare earth manganese oxide obtained by the preparation method of the comparative example 3 is subjected to hydrothermal aging at 750 ℃ for 10 hours, the highest conversion rate of the catalytic oxidation NO is 39%, and the conversion temperature corresponding to the highest conversion rate is 370 ℃. Fresh catalyst is used for catalyzing carbon particles to oxidize CO at a temperature of 390 ℃ and T50 2 The selectivity was 85.7%.
Comparative example 4:
according to SmMnO 3 Mixing the materials according to the Sm/Mn molar ratio in the rare earth manganese oxide to obtain a mixed solution with the total cation concentration of 1.0M; under the condition of stirring, uniformly and quickly adding the mixed feed liquid into 2.5M ammonium bicarbonate solution, wherein the pH value in the precipitation process is 5-8, the end point pH value is 7.5, and the temperature is controlled to be 70 ℃; filtering, washing and drying the precipitate, and roasting for 18 hours at 900 ℃ to obtain the rare earth manganese oxide SmMnO containing perovskite phase 3 。
After the rare earth manganese oxide obtained by adopting the preparation method of the comparative example 4 is subjected to hydrothermal aging at 750 ℃ for 10 hours, the highest conversion rate of catalytic oxidation NO is 26%, the temperature of catalytic oxidation T50 of the fresh catalyst catalytic carbon particles is 426 ℃, and CO is obtained 2 The selectivity was 80.2%.
Comparative example 5:
adding the solution with Mn ion concentration of 0.9M into 1.3M NaOH solution at uniform speed, wherein the pH value in the precipitation process is 9-13, the end point pH value is 9.2, and the temperature is controlled to be 80 ℃; filtering, washing and drying the precipitate, and roasting at 1000 ℃ for 10 hours to obtain Mn 3 O 4 Phase oxide.
After the rare earth manganese oxide obtained by the preparation method of the comparative example 5 is subjected to hydrothermal aging at 750 ℃ for 10 hours, the highest conversion rate of catalytic oxidation NO is 29%, and the conversion temperature corresponding to the highest conversion rate is 409 ℃.
EXAMPLE 1Ce 0.06 La 0.05 Y 0.08 Mn 0.21 Zr 0.65 Hf 0.05 O 1.84
According to Ce 0.06 La 0.05 Y 0.08 Mn 0.21 Zr 0.65 Hf 0.05 O 1.84 The molar ratio of Ce/Y/Zr/Hf in the rare earth manganese zirconium compound is 6:3:75:5, water is used for dissolution and batching, and a mixed solution with the concentration of 1.5M is obtained; under the stirring condition, uniformly and quickly adding the mixed solution into 2.1M NaOH solution, wherein the pH value in the precipitation process is 10-14, the end point pH value is 10, and the temperature is controlled to be 50 ℃; filtering, washing and drying the precipitate, and roasting the dried product at 800 ℃ for 7 hours to obtain the tetragonal rare earth zirconium oxide. The rare earth zirconium oxide is mixed with 2.2M Mn (NO) containing La and Y 3 ) 2 Mixing the solutions, heat-treating at 150deg.C for 5 hr, roasting at 680 deg.C for 12 hr in air atmosphere, and roasting at 500 deg.C for 2 hr in oxygen atmosphere to obtain tetragonal rare earth zirconium oxide with 86.9% molar content, mullite with 12.1% molar content, mn 2 O 3 The molar content of phase is 0.5%, mn 3 O 4 Rare earth manganese zirconium compound with the phase molar content of 0.5 percent. In the compound, mn (III) is Mn (IV) =1.2: 1.0.
after the rare earth manganese zirconium compound obtained by the preparation method of the embodiment of the invention is subjected to hydrothermal aging at 750 ℃ for 10 hours, the highest conversion rate of catalytic oxidation NO is 58%, and the conversion temperature corresponding to the highest conversion rate is 324 ℃. Fresh catalyst catalyzes oxidation of carbon particles with a T50 temperature of 352 ℃ and CO 2 The selectivity was 96.7%.
EXAMPLE 2Ce 0.14 La 0.03 Nd 0.04 Y 0.05 Mn 0.18 Zr 0.55 Hf 0.01 O 1.88
According to Ce 0.14 La 0.03 Nd 0.04 Y 0.05 Mn 0.18 Zr 0.55 Hf 0.01 O 1.88 The molar ratio of Ce/La/Zr/Hf in the rare earth manganese zirconium compound is 14:3:55:1, water is used for dissolution and batching, and a mixed solution with the concentration of 2.6M is obtained; under the stirring condition, uniformly and quickly adding the mixed feed liquid into 2.1M NaOH solution, wherein the pH value in the precipitation process is 8-11, the end point pH value is 8, and the temperature is controlled to be 40 ℃; filtering, washing and drying the precipitate, and roasting the dried product at 700 ℃ for 6 hours to obtain the tetragonal rare earth zirconium oxide. The rare earth zirconium oxide was mixed with 1.8M of a rare earth zirconium oxide containing Y, nd Mn (NO 3 ) 2 Mixing the solutions, heat treating at 200deg.C for 13 hr, roasting at 750deg.C in oxygen atmosphere for 10 hr, and roasting at 200deg.C in nitrogen atmosphere for 4 hr to obtain tetragonal rare earth zirconium oxide with content of 89.5%, mullite phase content of 9.0%, mn 2 O 3 Phase content of 0.8%, mn 3 O 4 Rare earth manganese zirconium compound with the phase content of 0.7 percent. In the compound, mn (III) is Mn (IV) =1.1: 1.0.
the rare earth manganese zirconium compound obtained by the preparation method of the embodiment of the invention is prepared byAfter 10h of hydrothermal aging at 750 ℃, the highest conversion rate of the catalytic oxidation NO is 57%, and the conversion temperature corresponding to the highest conversion rate is 319 ℃. Fresh catalyst for catalyzing oxidation of carbon particles with T50 temperature of 353 ℃ and CO 2 The selectivity was 96.5%.
EXAMPLE 3Ce 0.1 Eu 0.05 Gd 0.05 Mn 0.2 Zr 0.55 Hf 0.05 O 1.80
According to Ce 0.1 Eu 0.05 Gd 0.05 Mn 0.2 Zr 0.55 Hf 0.05 O 1.80 The molar ratio of Ce/Eu/Gd/Zr/Hf in the rare earth manganese zirconium compound is 3:5:1:55:5, water is used for dissolution and batching, and a mixed solution with the concentration of 2.4M is obtained; under the stirring condition, adding the mixed feed liquid and 2.5M NaOH solution into a reactor at uniform speed, wherein the pH value in the precipitation process is 9+/-0.2, the pH value at the end point is 9.0, and the temperature is controlled to be 40 ℃; filtering, washing and drying the precipitate, and roasting the dried product at 700 ℃ for 5 hours to obtain the tetragonal rare earth zirconium oxide. The rare earth zirconium oxide is mixed with 1.9M Mn (NO) containing Ce and Gd 3 ) 2 The solution was mixed while adding 1.8M NaOH with a certain amount of H 2 O 2 Filtering and washing the precipitate, then heat-treating at 170deg.C for 10h, and roasting at 600deg.C in air atmosphere for 10h to obtain tetragonal rare earth zirconium oxide with 88.3%, mullite phase with 8.6% and Mn 2 O 3 The phase content was 2.0%, mn 3 O 4 Rare earth manganese zirconium compound with 1.1 percent of phase content.
After the rare earth manganese zirconium compound obtained by the preparation method of the embodiment of the invention is subjected to hydrothermal aging at 750 ℃ for 10 hours, the highest conversion rate of catalytic oxidation NO is 56%, and the conversion temperature corresponding to the highest conversion rate is 308 ℃. Fresh catalyst is used for catalyzing carbon particles to oxidize CO at a temperature of T50 of 350 DEG C 2 The selectivity was 97.7%.
EXAMPLE 4Ce 0.4 La 0.02 Nd 0.05 Mn 0.2 Zr 0.3 Hf 0.03 O 1.82
According to Ce 0.4 La 0.02 Nd 0.05 Mn 0.2 Zr 0.3 Hf 0.03 O 1.82 Rare earth zirconium manganese complexThe molar ratio of Ce/La/Nd/ZrHf/nitrate in the mixed oxide is 2:2:5:30:3, water is used for dissolution and batching, and a mixed solution with the concentration of 1.1M is obtained; adding the mixed solution and 2.5M sodium hydroxide solution into a reactor at uniform speed under the stirring condition, controlling the pH value in the precipitation process to be 8+/-0.2, controlling the end point pH value to be 13, and controlling the temperature to be 55 ℃; the desired Ce (NO) 3 ) 3 ,La(NO 3 ) 3 And carrying out a second precipitation reaction on the solution and a sodium hydroxide solution, wherein the pH value of a precipitation end point is 10, carrying out post-treatment such as filtering, washing and the like on the precipitate, and roasting the dried product at 700 ℃ for 11 hours to obtain the tetragonal phase rare earth zirconium oxide with gradient distribution. The rare earth zirconium oxide is mixed with 4M Mn (NO) containing Ce and Nd 3 ) 3 Mixing the solutions, heat treating at 300deg.C for 6 hr, roasting at 800deg.C in oxygen atmosphere for 10 hr, and pulverizing the roasted product to obtain tetragonal rare earth zirconium oxide with 89.2%, mullite phase with 8.6%, mn 2 O 3 The phase content was 1.7%, mn 3 O 4 Rare earth manganese zirconium compound with the phase content of 0.5 percent.
After the rare earth manganese zirconium compound obtained by the preparation method of the embodiment of the invention is subjected to hydrothermal aging at 750 ℃ for 10 hours, the highest conversion rate of catalytic oxidation NO is 59%, and the conversion temperature corresponding to the highest conversion rate is 323 ℃. Fresh catalyst for catalyzing oxidation of carbon particles with CO at T50 of 336 DEG C 2 The selectivity was 96.8%.
EXAMPLE 5Ce 0.2 Sm 0.05 Mn 0.2 Zr 0.45 Ca 0.1 Hf 0.03 O 1.83
According to Ce 0.2 Sm 0.05 Mn 0.2 Zr 0.45 Ca 0.1 Hf 0.03 O 1.83 Molar ratio of Ce/Zr/Ca/Hf chloride salt in rare earth zirconium manganese composite oxide 15:45:10:3, water is used for dissolution and batching, and a mixed solution with the concentration of 1.0M is obtained; mixing the mixed solution with 2.3mol/L sodium hydroxide solution for precipitation reaction, controlling the precipitation temperature to 60 ℃, controlling the pH value in the precipitation process to be 5-13, regulating the pH value twice for fractional precipitation, firstly regulating the pH value to be 5 for precipitating zirconium ions and hafnium ions, and then slowly regulating the pH value to be 13 for separating ceriumAnd (3) precipitating the seed and calcium ions, wherein the pH value of the precipitation end point is 13, filtering, washing and drying the precipitate, and roasting the dried product at 650 ℃ for 8 hours to obtain the rare earth zirconium-based oxide with gradient steps. Mixing rare earth zirconium-based oxide with 4M Mn (NO) containing Sm, ce 3 ) 3 Mixing the solutions, heat treating at 190 deg.C for 9 hr, roasting at 500 deg.C in oxygen atmosphere for 6 hr, and roasting at 850 deg.C in oxygen atmosphere for 12 hr to obtain tetragonal phase rare earth zirconium oxide with 88.1%, mullite phase with 10.5% and Mn 2 O 3 The phase content was 0.7%, mn 3 O 4 Rare earth manganese zirconium compound with the phase content of 0.7 percent.
After the rare earth manganese zirconium compound obtained by the preparation method of the embodiment of the invention is subjected to hydrothermal aging at 750 ℃ for 10 hours, the highest conversion rate of catalytic oxidation NO is 60%, and the conversion temperature corresponding to the highest conversion rate is 298 ℃. Fresh catalyst is used for catalyzing carbon particles to oxidize CO at a temperature of 330 ℃ and T50 2 The selectivity was 95.8%.
Examples 6 to 44: in the same manner as in examples 1 to 4, except as noted below. The specific phase structure compositions and performance test results of the examples are shown in table 1.
Table 1 comparative and example phase structure compositions and performance test results
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Referring to FIG. 2, it can be seen from FIG. 2 that the rare earth manganese zirconium compound synthesized by the method provided by the invention contains tetragonal rare earth zirconium oxide and mullite phase YMn 2 O 5 ，Mn 2 O 3 Phase, mn 3 O 4 Phase, in hydrothermal agingThe product still has four phase structures after chemical conversion, and other impurity phases such as perovskite are not generated.
Accordingly, a third aspect of the embodiments of the present invention provides a catalyst comprising the above-described composite phase structured rare earth manganese zirconium compound.
The embodiment of the invention aims to protect a rare earth manganese zirconium compound with a composite phase structure, a preparation method thereof and a catalyst, wherein the chemical formula of the rare earth manganese zirconium compound is RE a Mn b Zr c L d O (2-δ) D β RE is rare earth element; l is a cation doping element, and D is an anion doping element; wherein, in terms of mole number, a is more than or equal to 0.10 and less than or equal to 0.50,0.09, b is more than or equal to 0.40,0.20 and less than or equal to 0.80,0, d is more than or equal to 0.40,0 and less than or equal to 0.30,0, beta is more than or equal to 0.10, and a+b+c+d=1; the composite phase structure of the rare earth manganese zirconium compound comprises: tetragonal rare earth zirconium oxide, mullite phase REMn 2 O 5 、Mn 3 O 4 Phase and Mn 2 O 3 And (3) phase (C). The technical scheme has the following effects:
by having tetragonal rare earth zirconium oxide, mullite phase REMn 2 O 5 、Mn 3 O 4 And Mn of 2 O 3 The rare earth manganese zirconium compound with the composite phase structure realizes the purposes of still having stable tetragonal rare earth zirconium oxide and mullite main phase structure at high temperature, not generating perovskite phase, and maintaining higher NO catalytic oxidation and carbon particle oxidation performance, and meets the use requirements of DOC and DPF catalysts on high-temperature stability and high catalytic activity of coating materials.
It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explanation of the principles of the present invention and are in no way limiting of the invention. Accordingly, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present invention should be included in the scope of the present invention. Furthermore, the appended claims are intended to cover all such changes and modifications that fall within the scope and boundary of the appended claims, or equivalents of such scope and boundary.
Claims (13)
1. A rare earth manganese zirconium compound with a composite phase structure is characterized in that the chemical formula of the rare earth manganese zirconium compound is RE a Mn b Zr c L d O (2-δ) D β RE is rare earth element; l is a cation doping element, and D is an anion doping element;
wherein, in terms of mole number, a is more than or equal to 0.10 and less than or equal to 0.50,0.09, b is more than or equal to 0.40,0.20 and less than or equal to 0.80,0, d is more than or equal to 0.40,0 and less than or equal to 0.30,0, beta is more than or equal to 0.10, and a+b+c+d=1;
the composite phase structure of the rare earth manganese zirconium compound comprises: tetragonal rare earth zirconium oxide, mullite phase REMn 2 O 5 、Mn 3 O 4 Phase and Mn 2 O 3 And (3) phase (C).
2. The composite phase structure rare earth manganese zirconium compound according to claim 1, wherein,
the mole content of the tetragonal phase rare earth zirconium oxide is 60.0% -95.0%, and the mullite phase REMn 2 O 5 The molar content of (2) is 3.0-30.0%, and the Mn is as follows 2 O 3 The molar content of the phase is 0.1-5.0%, mn 3 O 4 The molar content of the phase is 0.1 to 5.0 percent;
preferably, the mole content of the tetragonal rare earth zirconium oxide is 70.0-90.0%, and the mullite phase REMn 2 O 5 The molar content of (2) is 5.0-25.0%, and the Mn is as follows 2 O 3 The molar content of the phase is 0.5-2.0%, mn 3 O 4 The molar content of the phases is 0.5% -2.0%.
3. The composite phase structured rare earth manganese zirconium compound according to claim 2, wherein manganese in the rare earth manganese zirconium compound comprises: trivalent Mn and tetravalent Mn, wherein the mole ratio of the trivalent Mn to the tetravalent Mn on the surface is 0.8:1-5.0:1;
preferably, the molar ratio of trivalent Mn to tetravalent Mn of the surface is in the range of 0.9:1 to 2.5:1.
4. The composite phase structure rare earth manganese zirconium compound according to claim 3, wherein,
the cation doping element L includes: alkaline earth metals, transition metals, aluminum or silicon, present in the tetragonal phase rare earth zirconium oxide and/or in the mullite phase REMn 2 O 5 In (a) and (b);
the anion doping element D includes: at least one of anions N, P, F and S is present in the tetragonal rare earth zirconium oxide, the mullite phase REMn 2 O 5 Mn of the alloy 3 O 4 Phases and Mn 2 O 3 At least one of the phases;
the morphology of the cation doping element L and the anion doping element D in the rare earth manganese zirconium compound includes at least one of an oxide, a nitrogen-containing compound, a fluoride, a phosphate, and a sulfate.
5. The composite phase structure rare earth manganese zirconium compound according to claim 4, wherein,
the cation doping element L includes: at least one of Al, si, ga, ge, in, hf, ba, sr, mg, ca, fe, co, ni, cu, zn, V, ti, cr, mo, W, sn and Nb;
the anion doping element D includes: at least one of anions N, P, F and S.
6. The composite phase structure rare earth manganese zirconium compound according to claim 5, wherein,
the RE comprises: la, ce, pr, nd, sm, eu, gd, tb, dy, ho, er, tm, yb, lu, Y and Sc;
preferably, the RE includes: la, ce, pr, nd, sm, eu, gd and Y.
7. A method for preparing a rare earth manganese zirconium compound with a composite phase structure, which is characterized by being used for preparing the rare earth manganese zirconium compound with the composite phase structure according to any one of claims 1-6, and comprising the following steps:
s1, mixing all zirconium, all or part of RE and all or part of salt solution of cation doping element L, adding alkaline substances for precipitation reaction, and filtering, washing, drying and roasting to obtain RE-L-containing rare earth zirconium oxide;
s2, mixing all manganese, the rest RE and the rest salt solution of the cation doping element L with the rare earth zirconium oxide obtained in the step S1 to obtain a compound precursor;
and S3, performing heat treatment on the composite compound precursor obtained in the step S2 and calcining the composite compound precursor in a preset atmosphere to obtain the composite-phase rare earth manganese zirconium compound.
8. The method for preparing a rare earth manganese zirconium compound with a composite phase structure according to claim 7, further comprising:
in the step S2, mixing the mixed salt solution of all manganese, the rest RE and the rest cation doping element L with the rare earth zirconium oxide obtained in the step S1, adding an alkaline solution and an oxidant at the same time, reacting to obtain composite compound slurry, and filtering and washing to obtain a composite compound precursor.
9. The method for producing a composite phase structured rare earth manganese zirconium compound according to claim 7 or 8, further comprising:
the anionic doping element D is added at the same time as the mixed salt solution is prepared in step S1 and/or step S2.
10. The method for preparing the rare earth manganese zirconium compound with the composite phase structure according to claim 9, wherein,
the manganese source in the mixed brine solution comprises: at least one of chloride, nitrate, sulfate and acetate, preferably manganese nitrate;
the zirconium source in the mixed brine solution comprises: at least one of oxychloride, nitrate, sulfate, acetate and citrate, preferably zirconyl nitrate;
the brine solution containing the cation doping elements L and RE includes: a molten salt or aqueous solution of at least one of a chloride, nitrate, sulfate, acetate, citrate, amino acid salt, organosilicon compound, preferably nitrate;
the alkaline substance includes: at least one of urea, hydroxide, ammonia, carbonate, and bicarbonate, the bicarbonate comprising: at least one of ammonium, potassium, sodium and magnesium elements, wherein the hydroxide comprises at least one of ammonium, sodium, potassium and magnesium elements, and preferably, the alkaline substance comprises: at least one of sodium hydroxide, urea, ammonia water and ammonium bicarbonate;
the roasting is carried out in a preset atmosphere which comprises air, CO and N 2 Or H 2 One or two of the following components;
the oxidizing agent comprises: at least one of hydrogen peroxide, persulfate, air, and ozone;
the anion doping element D includes: at least one of nitrate, fluoride, phosphate and sulfate; preferably, the anion doping element D includes: nitrate and/or sulfate.
11. The method for preparing the rare earth manganese zirconium compound with the composite phase structure according to claim 10, wherein,
the pH value in the precipitation process is controlled to be 4.5-14, preferably 5-11;
the pH value of the precipitation end point is controlled to be 8-13, preferably 9-11;
the temperature during the precipitation is 5-120 ℃, preferably 20-80 ℃.
12. The method for preparing the rare earth manganese zirconium compound with the composite phase structure according to claim 11, wherein,
the roasting condition of the rare earth zirconium oxide is kept for 1 to 20 hours within the temperature range of 500 to 1000 ℃; preferably, the temperature is kept within the range of 600-900 ℃ for 2-10 h;
the heat treatment temperature is 100-500 ℃ and the time is 2-30 hours; preferably, the heat treatment temperature is 150-300 ℃ and the time is 6-12 h;
the calcination condition is kept for 1 to 20 hours within the range of 400 to 1000 ℃; preferably at 500-800 deg.C for 3-10 h.
13. A catalyst comprising the composite phase structured rare earth manganese zirconium compound according to any one of claims 1 to 6.
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