WO2021180142A1 - 一种混合协同强化型低温scr脱硝催化剂及其制备方法 - Google Patents

一种混合协同强化型低温scr脱硝催化剂及其制备方法 Download PDF

Info

Publication number
WO2021180142A1
WO2021180142A1 PCT/CN2021/080079 CN2021080079W WO2021180142A1 WO 2021180142 A1 WO2021180142 A1 WO 2021180142A1 CN 2021080079 W CN2021080079 W CN 2021080079W WO 2021180142 A1 WO2021180142 A1 WO 2021180142A1
Authority
WO
WIPO (PCT)
Prior art keywords
catalyst
temperature
denitration catalyst
ceo
hybrid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2021/080079
Other languages
English (en)
French (fr)
Inventor
高翔
宋浩
郑成航
吴卫红
刘少俊
杨洋
余鸿敏
邹仁智
张宇
张烁
张涌新
翁卫国
岑可法
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Original Assignee
Zhejiang University ZJU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU filed Critical Zhejiang University ZJU
Publication of WO2021180142A1 publication Critical patent/WO2021180142A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/19—Catalysts containing parts with different compositions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8621—Removing nitrogen compounds
    • B01D53/8625—Nitrogen oxides
    • B01D53/8628—Processes characterised by a specific catalyst
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/002—Mixed oxides other than spinels, e.g. perovskite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56—Platinum group metals
    • B01J23/64—Platinum group metals with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/652—Chromium, molybdenum or tungsten
    • B01J23/6525—Molybdenum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56—Platinum group metals
    • B01J23/64—Platinum group metals with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/652—Chromium, molybdenum or tungsten
    • B01J23/6527—Tungsten
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56—Platinum group metals
    • B01J23/64—Platinum group metals with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/656—Manganese, technetium or rhenium
    • B01J23/6562—Manganese
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/83—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with rare earths or actinides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/84—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/85—Chromium, molybdenum or tungsten
    • B01J23/88—Molybdenum
    • B01J23/887—Molybdenum containing in addition other metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/8877—Vanadium, tantalum, niobium or polonium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/84—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/85—Chromium, molybdenum or tungsten
    • B01J23/888—Tungsten
    • B01J23/8885—Tungsten containing also molybdenum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/04—Mixing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2523/00—Constitutive chemical elements of heterogeneous catalysts

Definitions

  • the invention relates to a preparation method of a denitration catalyst, in particular to a mixed and synergistic enhanced low-temperature SCR denitration catalyst and a preparation method thereof, and belongs to the technical field of catalysts.
  • SCR Selective Catalytic Reduction
  • the operating temperature of commercial vanadium-titanium catalysts is generally 300-420°C, and the temperature is lower than 300°C.
  • the denitration efficiency of the catalyst will be significantly reduced, and the desired effect cannot be achieved.
  • the exhaust gas temperature of most industrial boilers, kilns, steel industry and coking furnaces in my country is lower than 250°C, and traditional commercial vanadium-titanium catalysts can no longer meet their denitration requirements. Therefore, it is of great significance to develop a low-temperature SCR denitration catalyst suitable for my country's national conditions.
  • the purpose of the present invention is to provide a hybrid and synergistic enhanced low-temperature SCR denitration catalyst to solve the problems of low low-temperature activity of commercial vanadium-titanium catalysts in the prior art and difficulty in achieving the required denitration efficiency.
  • a hybrid and synergistic enhanced low-temperature SCR denitration catalyst which is a mixture of two catalysts, one is an oxidation catalyst MnO 2 -CeO 2 or CoO 3 -CeO 2 or a combination of two in any ratio ,
  • the molar ratio of MnO 2 and CeO 2 in MnO 2 -CeO 2 is any ratio
  • the molar ratio of CoO 3 and CeO 2 in CoO 3 -CeO 2 is any ratio
  • the other is a medium temperature denitration catalyst V 2 O 5 -WO 3- MoO 3 /TiO 2 , wherein the mass fraction of V 2 O 5 is 0.5% to 2%, the mass fraction of WO 3 is 0-5%, and the mass fraction of MoO 3 is 0-5%
  • the oxidation catalyst The mass ratio to the medium temperature denitration catalyst is 1: (0.5-3).
  • the inventor of the present invention developed a hybrid and synergistically enhanced low-temperature SCR catalyst based on the vanadium-titanium catalyst based on the long-term research and development of flue gas denitration catalysts. Compared with the current commercial SCR catalysts, the inventors have greatly reduced The reaction activation energy of the catalyst in the low temperature range of 150-250°C greatly improves the catalyst activity, and the catalyst has good anti-poisoning ability. It is a low-cost, high-performance new low-temperature SCR catalyst.
  • the oxidation catalyst is mixed and ground with a moderate temperature denitration catalyst, an appropriate amount of nitric acid solution with a pH of 3 to 4, and a binder, and dried to obtain a catalyst powder with a particle size of 100 to 200 meshes.
  • Low temperature SCR denitration catalyst The nitric acid solution is used in the mixed catalyst to improve the dispersibility of each catalyst.
  • the amount of nitric acid solution with a pH of 3 to 4 is 3 to 5 parts by weight, and the amount of binder is 0.02 to 0.05 parts by weight.
  • the molar ratio of MnO 2 and CeO 2 in MnO 2 -CeO 2 is 5:5-6:4, and the molar ratio of CoO 3 and CeO 2 in CoO 3 -CeO 2 is 8:2-9:1.
  • the mass ratio of the oxidation catalyst to the medium temperature denitration catalyst is 1: (1-2).
  • the binder is one or two of polyethylene glycol or carboxymethyl cellulose.
  • a method for preparing a hybrid and synergistic enhanced low-temperature SCR denitration catalyst includes the following steps:
  • Step S101 preparation of oxidation catalyst
  • Step S102 preparation of medium temperature denitration catalyst
  • Step S103 mixing and tableting of the two catalysts
  • the rotation speed of the ball mill in step S103 is 200-300 revolutions per minute.
  • step S101 preparation of oxidation catalyst
  • step S102 preparation of medium temperature denitration catalyst
  • TiO 2 is used as a carrier after drying
  • the nitrite intermediate product formed by the oxidation catalyst can quickly react with the adsorbed NH 3 in the medium temperature denitration catalyst, which greatly reduces the activation energy of the reaction and greatly improves the activity of the catalyst.
  • the activity of the catalyst is more than 2 times higher than that of the two separate catalysts, which has obvious synergistic effect;
  • the present invention adopts the method of first preparing two catalysts separately, and then mixing and fixing the two by adding a binder and an appropriate amount of nitric acid to prepare a mixed catalyst.
  • the low-temperature SCR denitration catalyst suppresses the side effects caused by the interaction between the two active components;
  • reagents used in the following examples can be purchased from conventional biochemical reagent stores.
  • the core of the present invention is to provide a hybrid and synergistic enhanced low-temperature SCR denitration catalyst, which is called specific embodiment 1.
  • the catalyst is a mixture of two catalysts, one is an oxidation catalyst MnO 2 -CeO 2 or CoO 3 -CeO 2 or a combination of two in any ratio (including the case where one of them is 0, the same below), the molar ratio of MnO 2 and CeO 2 in MnO 2 -CeO 2 is any ratio, CoO 3 -CeO in CoO and CeO 2 mole ratio of 2 than any other is a medium temperature denitration catalyst V 2 O 5 -WO 3 -MoO 3 / TiO 2, wherein the mass fraction of V 2 O 5 is 0.5% to 2%, The mass fraction of WO 3 is 0-5%, and the mass fraction of MoO 3 is 0-5%; the mass ratio of the oxidation catalyst to the medium temperature denitration catalyst is 1: (0.5-3).
  • the research focus of the present invention is the synergistic effect of the combination of the two catalysts. Tests have proved that the catalytic performance is the best when the oxidation catalyst and the medium temperature denitration catalyst are prepared separately and then physically compressed and mixed for molding.
  • the amount of nitric acid solution with a pH of 3 to 4 is 3 to 5 parts by weight, and the amount of binder is 0.02 to 0.05 parts by weight. share.
  • the mass ratio of the oxidation catalyst to the medium temperature denitration catalyst is 1: (1-2).
  • the best mass ratio between the two is slightly different due to the specific active components of the catalyst selected.
  • the oxidation catalyst is MnO 2 -CeO 2 and the medium temperature denitration catalyst is V 2 O 5 -WO 3 /TiO 2 , the best mass ratio of the two is 1:1;
  • the oxidation catalyst is CoO 3 -CeO 2 and the medium temperature denitration catalyst is V 2 O 5 -WO 3 -MoO 3 /TiO 2 or V 2 O 5 -MoO 3 /TiO 2 , the best mass ratio of the two is 1: 2;
  • the optimal ratio of the two catalysts is that the molar ratio of MnO 2 to CeO 2 in MnO 2 -CeO 2 is 5:5 to 6:4, and the molar ratio of CoO 3 to CeO 2 in CoO 3 -CeO 2 is 8. :2 ⁇ 9:1.
  • the best process for mixing and tableting of the two catalysts is to mix and grind the oxidation catalyst, the medium temperature denitration catalyst, an appropriate amount of nitric acid solution with a pH of 3 to 4, and a binder, and dry them to obtain a particle size of 100 to 100.
  • the catalyst powder of 200 meshes is mechanically pressed into tablets to obtain the low-temperature SCR denitration catalyst.
  • the binder is one or two of polyethylene glycol or carboxymethyl cellulose.
  • the low temperature is in the temperature range of 150-250°C.
  • the carrier obtained in step 3) and the solution obtained in step 4) with a pH value of less than 2 are mixed and stirred uniformly by immersion method, ultrasonically shaken with an ultrasonic cleaner for 20 minutes, and then stirred for 10 minutes while steaming to dryness in a water bath at 80°C, and then in an oven Bake at 110°C for 12 hours, and then calcined at 500°C to obtain a V 2 O 5 -WO 3 /TiO 2 catalyst.
  • the catalyst composition in mass percentage is: carrier TiO 2 94%, active component V 2 O 51 %, active ingredient WO 3 5%.
  • the prepared mixed synergistic enhanced low-temperature SCR denitration catalyst (hereinafter referred to as the mixed catalyst) was crushed and sieved to obtain catalyst particles with a particle size between 60 mesh and 40 mesh.
  • Catalyst activity test 0.2g each of the three kinds of catalyst particles prepared in this example were put into a catalyst denitration activity evaluation device for activity evaluation, and the activity evaluation was carried out in a fixed bed reactor with an inner diameter of 8 mm. O 2 /N 2 , NO/N 2 , NH 3 /N 2 and N 2 are mixed after being controlled by a mass flow meter.
  • the injection volume of the micro-injection pump By adjusting the injection volume of the micro-injection pump, deionized water is injected into the heating pipe to vaporize to realize the addition of water vapor ,
  • the simulated flue gas is obtained, the composition is 5% O 2 , 1000 ppmNO, 1000 NH 3 , 5% H 2 O, N 2 is the balance gas, and the space velocity is 200,000 h -1 .
  • the reaction temperature is 200°C, and NH 3 /NO is 1.
  • the gas composition is tested by Gasmet FTIR Dx4000 flue gas analyzer manufactured by Finland Gasmet Company. The denitration efficiency and selectivity of the test are shown in Table 1.
  • the inventors also compared the effects of the mixed catalyst obtained by mechanical mixing and tableting (measured under the same experimental conditions).
  • the denitration efficiency of the mixed catalyst obtained by mechanical mixing was 65.5%.
  • the obtained mixed catalyst has a denitration efficiency of 92.7%, which once again proves the synergistic effect of the two catalysts in the present invention. Since the two have a larger contact area and a closer contact distance after the tableting treatment, it is beneficial to the intermediate product nitrite. Therefore, the denitration efficiency of the mixed catalyst has been improved qualitatively.
  • the carrier obtained in step 3) and the solution obtained in step 4) with a pH value of less than 2 are mixed and stirred uniformly by immersion method, ultrasonically shaken with an ultrasonic cleaner for 20 minutes, and then stirred for 10 minutes while steaming to dryness in a water bath at 80°C, and then in an oven Bake at 110°C for 12 hours, and then calcined at 600°C to obtain a V 2 O 5 -WO 3 -MoO 3 /TiO 2 catalyst.
  • the catalyst composition in mass percentage is: carrier TiO 2 93%, active components V 2 O 5 1%, active component WO 3 3%, active component MoO 3 3%.
  • Catalyst activity test The specific test method is the same as that of the second embodiment, and the denitration efficiency and selectivity tested are shown in Table 2.
  • the carrier obtained in step 3) and the solution obtained in step 4) with a pH value of less than 2 are mixed and stirred uniformly by immersion method, ultrasonically shaken with an ultrasonic cleaner for 20 minutes, and then stirred for 10 minutes while steaming to dryness in a water bath at 80°C, and then in an oven Bake at 110°C for 12 hours, and then calcined at 600°C to obtain a V 2 O 5 -WO 3 -MoO 3 /TiO 2 catalyst.
  • the catalyst composition in mass percentage is: carrier TiO 2 92%, active components V 2 O 5 2%, active component WO 3 4%, active component MoO 3 2%.
  • Catalyst activity test The specific test method is the same as that of the second embodiment, and the denitration efficiency and selectivity tested are shown in Table 3.
  • the carrier obtained in step 3) and the solution obtained in step 4) with a pH value of less than 2 are mixed and stirred uniformly by immersion method, ultrasonically shaken with an ultrasonic cleaner for 20 minutes, and then stirred for 10 minutes while steaming to dryness in a water bath at 80°C, and then in an oven Bake at 110°C for 12h, and then calcined at 600°C to obtain a supported V 2 O 5 -MoO 3 /TiO 2 catalyst.
  • the catalyst composition in mass percentage is: carrier TiO 2 94%, active component V 2 O 5 1%, active component MoO 3 5%.
  • Catalyst activity test The specific test method is the same as that of the second embodiment, and the denitration efficiency and selectivity tested are shown in Table 4.
  • the catalyst prepared in the second embodiment as an example to investigate the performance of the catalyst at different temperatures.
  • the test method refer to the aforementioned catalyst activity test, and the data is shown in Table 5.
  • the mixed catalyst of the present invention still maintains a good denitration efficiency at low temperatures, and can be applied in a temperature range of 150-250°C. It is obvious that the higher the temperature, the better the catalytic activity. Therefore, its Temperatures in excess of 250°C must also apply.
  • this test example prepared V 2 O 5 -MnO 2 -WO 3 / under the same conditions as in the previous test.
  • TiO 2 catalyst, V 2 O 5 -CoO 3 -WO 3 /TiO 2 catalyst and V 2 O 5 -CeO 2 -WO 3 /TiO 2 catalyst, the specific methods are as follows:
  • step 1) and the solution obtained in step 2) with a pH value of less than 2 are mixed and stirred uniformly by immersion method, ultrasonically shaken by an ultrasonic cleaner for 20 minutes, and then stirred for 10 minutes while steaming to dryness in a water bath at 80°C, and then in an oven Bake at 110 °C for 12 hours, and then calcined at 500 °C to obtain V 2 O 5 -MnO 2 -WO 3 /TiO 2 catalyst or V 2 O 5 -CoO 3 -WO 3 /TiO 2 catalyst or V 2 O 5 -CeO 2 -WO 3 /TiO 2 catalyst, the catalyst composition in mass percentage is: carrier TiO 2 89%, active component V 2 O 5 1%, active component WO 3 5%, active component MnO 2 Or CoO 3 or CeO 2 5%.
  • the catalyst was ground into catalyst particles with a particle size between 60 mesh and 40 mesh; the catalyst activity test was carried out using the aforementioned method, and the results are shown in Table

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Catalysts (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)

Abstract

本发明涉及一种混合协同强化型低温SCR脱硝催化剂及其制备方法，属于催化剂技术领域。一种混合协同强化型低温SCR脱硝催化剂，该催化剂是由两种催化剂混合而成，一种是氧化型催化剂MnO 2-CeO 2或CoO 3-CeO 2中的一种或两种任意比例的组合，MnO 2-CeO 2中MnO 2和CeO 2的摩尔比为任意比，CoO 3-CeO 2中CoO 3和CeO 2的摩尔比为任意比，另一种是中温脱硝催化剂V 2O 5-WO 3-MoO 3/TiO 2，其中V 2O 5的质量分数为0.5％～2％，WO 3的质量分数为0-5％，MoO 3的质量分数为0-5％；所述氧化型催化剂与中温脱硝催化剂的质量比为1：(0.5～3)。

Description

一种混合协同强化型低温SCR脱硝催化剂及其制备方法 技术领域
本发明涉及一种脱硝催化剂的制备方法，特别涉及一种混合协同强化型低温SCR脱硝催化剂及其制备方法，属于催化剂技术领域。
背景技术
我国以煤为主的能源结构在很长一段时间内都不会发生根本改变，煤燃烧产生的氮氧化物是主要的大气污染物之一，会导致许多环境污染问题，如酸雨、光化学烟雾、臭氧层空洞等，同时还会对人体健康造成严重的危害。
选择性催化还原(SCR)技术是目前脱硝效率最高的技术，已成为我国燃煤电厂烟气脱硝的首选，然而，商用钒钛催化剂的运行温度一般为300-420℃，温度低于300℃时，催化剂脱硝效率会显著降低，无法达到理想效果。而我国大部分工业锅炉、窑炉、钢铁行业以及焦化炉等的排放烟气温度都低于250℃，传统的商用钒钛催化剂已经无法满足其脱硝要求。因此，开发适合我国国情的低温SCR脱硝催化剂具有重要的意义。
发明内容
本发明的目的在于提供一种混合协同强化型低温SCR脱硝催化剂，以解决现有技术中商用钒钛催化剂低温活性低，脱硝效率难以达到要求的问题。
本发明解决其技术问题所采用的技术方案是：
一种混合协同强化型低温SCR脱硝催化剂，该催化剂是由两种催化剂混合而成，一种是氧化型催化剂MnO 2-CeO 2或CoO 3-CeO 2中的一种或两种任意比例的组合，MnO 2-CeO 2中MnO 2和CeO 2的摩尔比为任意比，CoO 3-CeO 2中CoO 3和CeO 2的摩尔比为任意比，另一种是中温脱硝催化剂V 2O 5-WO 3-MoO 3/TiO 2，其中V 2O 5的质量分数为0.5％～2％，WO 3的质量分数为0-5％，MoO 3的质量分数为0-5％；所述氧化型催化剂与中温脱硝催化剂的质量比为1：(0.5～3)。
针对现有技术的不足，本发明人在长期从事烟气脱硝催化剂研发的基础上，以钒钛催化剂为基础开发一种混合协同强化型低温SCR催化剂，相比于目前商用SCR催化剂，大大降低了催化剂在150-250℃的低温范围区间内的反应活化能，使催化剂活性得到了大幅度提高，并且催化剂具有较好的抗中毒能力，是一种低成本、高性能的新型低温 SCR催化剂。
发明人在研究工作中发现，通过氧化型催化剂MnO 2-CeO 2或CoO 3-CeO 2与钒钛催化剂进行物理结合，NO在氧化型催化剂表面上会形成亚硝酸盐等中间物种，这些中间物种会迁移至钒钛催化剂上，与钒钛催化剂上吸附的活性氨物种发生快速SCR反应，从而大大提升了催化剂的反应速率。而物理结合的方式，又避免了Mn-V或Co-V之间的化学键合作用产生的副反应，如N 2O的生成，占据活性位等，使催化剂保持了较高的选择性。
作为优选，将氧化型催化剂与中温脱硝催化剂以及适量pH为3～4的硝酸溶液、粘结剂混合研磨，烘干，得到颗粒度为100～200目的催化剂粉末，机械压片成型即得到所述低温SCR脱硝催化剂。硝酸溶液在混合催化剂中用于提高各催化剂的分散性。
作为优选，该混合协同强化型低温SCR脱硝催化剂中，以氧化型催化剂为1重量份计，pH为3～4的硝酸溶液用量为3～5重量份、粘结剂用量为0.02～0.05重量份。
作为优选，MnO 2-CeO 2中MnO 2和CeO 2的摩尔比为5:5～6:4，CoO 3-CeO 2中CoO 3和CeO 2的摩尔比为8:2～9:1。
作为优选，所述氧化型催化剂与中温脱硝催化剂的质量比为1：(1～2)。
作为优选，所述粘结剂为聚乙二醇或羧甲基纤维素中的一种或两种。
一种混合协同强化型低温SCR脱硝催化剂的制备方法，该方法包括如下步骤：
步骤S101：氧化型催化剂的制备，
步骤S102：中温脱硝催化剂的制备，
步骤S103：两种催化剂的混合压片，
将1重量份氧化型催化剂、0.5～2重量份中温脱硝催化剂、3～5重量份pH为3～4的硝酸溶液、0.02～0.05重量份粘结剂混合，球磨机中球磨1～2h，然后在200～250℃烘干，将催化剂磨成颗粒度为100～200目的粉末，机械压片成型，即得到低温SCR脱硝催化剂。
进一步优选的是，步骤S103中球磨机的转速为200～300转/分钟。
作为优选，步骤S101：氧化型催化剂的制备，
1)将硝酸锰、硝酸铈和柠檬酸在25℃～35℃下搅拌使之溶于去离子水中，其中柠檬酸与金属盐的摩尔比为1.2～1.5:1，得到溶液A；
或将硝酸钴、硝酸铈和柠檬酸在25℃～35℃下搅拌使之溶于去离子水中，其中柠檬 酸与金属盐的摩尔比为1.2～1.5:1，得到溶液B；
2)将溶液A或溶液B加热至75～85℃并不停搅拌，直至溶液呈凝胶状，然后在烘箱中烘干，再在400℃～500℃温度条件下煅烧3～5h后，将催化剂研磨成颗粒度小于300目的粉末，得到氧化型催化剂。
作为优选，步骤S102：中温脱硝催化剂的制备，
TiO 2干燥后作为载体，
将偏钒酸铵、偏钨酸铵和钼酸铵在50℃～70℃温度下搅拌使之溶于草酸溶液中，得到pH值小于2的溶液D；
将TiO 2载体浸渍于溶液D中搅拌均匀，超声震荡，再用水浴边蒸干边搅拌10～60min，然后在烘箱中烘干，再在500℃～600℃温度条件下煅烧3～5h后，将催化剂研磨成颗粒度小于300目的粉末，得到中温脱硝催化剂。
一种本发明所述的混合协同强化型低温SCR脱硝催化剂在低温烟气脱硝方面的催化应用，所述的低温是150～250℃的温度范围内。
与现有技术相比，本发明的优点在于：
(1)在低温SCR反应过程中，氧化型催化剂形成的亚硝酸盐中间产物可快速与中温脱硝催化剂中吸附的NH 3发生反应，大大降低了反应活化能，并大幅提高了催化剂的活性，同样条件下，该催化剂活性比两种单独的催化剂活性均提高了2倍以上，具有显而易见的协同效果；
(2)相比于氧化型催化剂，其选择性得到了较大提高；
(3)相比于直接合成的催化剂，本发明采用先各自制备两种催化剂，然后通过添加粘合剂及适量硝酸将两者混合固定，制备得到混合催化剂，该制备方法得到的混合协同强化型低温SCR脱硝催化剂抑制了两种活性组分之间相互影响带来的副作用；
(4)制备工艺简单、成本较低等。
具体实施方式
下面通过具体实施例，对本发明的技术方案作进一步的具体说明。应当理解，本发明的实施并不局限于下面的实施例，对本发明所做的任何形式上的变通和/或改变都将落入本发明保护范围。
在本发明中，若非特指，所有的份、百分比均为重量单位，所采用的设备和原料等 均可从市场购得或是本领域常用的。下述实施例中的方法，如无特别说明，均为本领域的常规方法。
下述实施例中所用的试剂，如无特殊说明，可以从常规生化试剂商店购买得到。
本发明的核心是提供一种混合协同强化型低温SCR脱硝催化剂，称其为具体实施方式一，该催化剂是由两种催化剂混合而成，一种是氧化型催化剂MnO 2-CeO 2或CoO 3-CeO 2中的一种或两种任意比例的组合(含其中之一为0的情况，下同)，MnO 2-CeO 2中MnO 2和CeO 2的摩尔比为任意比，CoO 3-CeO 2中CoO 3和CeO 2的摩尔比为任意比，另一种是中温脱硝催化剂V 2O 5-WO 3-MoO 3/TiO 2，其中V 2O 5的质量分数为0.5％～2％，WO 3的质量分数为0-5％，MoO 3的质量分数为0-5％；所述氧化型催化剂与中温脱硝催化剂的质量比为1：(0.5～3)。
本发明的研究重点为两种催化剂的组合后的协同效应。试验证明，所述氧化型催化剂与中温脱硝催化剂两者分别制备后再物理压片混合成型时，催化性能最佳。
更进一步地，该混合协同强化型低温SCR脱硝催化剂中，以氧化型催化剂为1重量份计，pH为3～4的硝酸溶液用量为3～5重量份、粘结剂用量为0.02～0.05重量份。
更进一步地，所述氧化型催化剂与中温脱硝催化剂的质量比为1：(1～2)。两者最佳的质量比因选择的具体催化剂活性成分而略有不同，
当氧化型催化剂为MnO 2-CeO 2，中温脱硝催化剂为V 2O 5-WO 3/TiO 2时，两者最佳质量比为1：1；
当氧化型催化剂为CoO 3-CeO 2，中温脱硝催化剂为V 2O 5-WO 3-MoO 3/TiO 2或V 2O 5-MoO 3/TiO 2时，两者最佳质量比为1：2；
两种催化剂各自的最佳配比为，MnO 2-CeO 2中MnO 2和CeO 2的摩尔比为5:5～6:4，CoO 3-CeO 2中CoO 3和CeO 2的摩尔比为8:2～9:1。
更进一步地，两种催化剂的混合压片最佳工艺是：将氧化型催化剂与中温脱硝催化剂以及适量pH为3～4的硝酸溶液、粘结剂混合研磨，烘干，得到颗粒度为100～200目的催化剂粉末，机械压片成型即得到所述低温SCR脱硝催化剂。
更进一步地，所述粘结剂为聚乙二醇或羧甲基纤维素中的一种或两种。
所述的混合协同强化型低温SCR脱硝催化剂在低温烟气脱硝方面的催化应用，其中所述的低温是150～250℃的温度范围内。
在具体实施方式一的基础上，进一步对上述混合协同强化型低温SCR脱硝催化剂的制备方法做限定，得到具体实施方式二，该方法具体步骤是：
1)将硝酸锰、硝酸铈和柠檬酸在30℃下搅拌使之溶于去离子水中，其中柠檬酸与金属盐的摩尔比为1.2：1，硝酸锰与硝酸铈的摩尔比为1:9，得到溶液；
2)将上述溶液加热至80℃并不停搅拌，直至溶液呈凝胶状，然后在烘箱中烘干，再在450℃温度条件下煅烧3h后，将催化剂研磨成颗粒度小于300目的粉末，得到催化剂A(MnO 2-CeO 2)，另外取部分催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒作为对比样品；
3)将TiO 2在105℃温度下干燥12h，作为载体；
4)将偏钒酸铵和偏钨酸铵在50℃温度下搅拌使之溶于草酸溶液中，得到pH值小于2的溶液；
5)将步骤3)得到的载体、步骤4)得到pH值小于2的溶液采用浸渍法混合搅拌均匀，利用超声波清洗仪超声震荡20min，再用水浴80℃边蒸干边搅拌10min，然后在烘箱中110℃下烘12h，再在500℃温度条件下煅烧，得到了V 2O 5-WO 3/TiO 2催化剂，以质量百分比计催化剂组成为：载体TiO 2 94％，活性组分V 2O 5 1％，活性组分WO 3 5％。将催化剂研磨成颗粒度小于300目的粉末，得到催化剂B(V 2O 5-WO 3/TiO 2)，另外取部分催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒作为对比样品；
6)将1份催化剂A(MnO 2-CeO 2)、1份催化剂B(V 2O 5-WO 3/TiO 2)、4份pH为3的硝酸溶液、0.05份聚乙二醇混合在一起，放入球磨机中以200转/分钟的转速进行球磨混合2h，然后在烘箱中200℃烘干，将催化剂磨成颗粒度为100-200目的粉末，放入压片机中进行压片，经压片成型即得到本发明所述的混合协同强化型低温SCR脱硝催化剂。
为了对比实验效果，将制备的混合协同强化型低温SCR脱硝催化剂(以下简称混合催化剂)粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒。
催化剂活性试验取本实施例制备得到的三种催化剂颗粒各0.2g分别放入催化剂脱硝活性评价装置进行活性评价，活性评价在内径为8mm的固定床反应器中进行。O 2/N 2、NO/N 2、NH 3/N 2和N 2经质量流量计控制后混合，通过调节微量注射泵的注射量将去离子水注入加热管路汽化来实现水蒸气的加入，得到模拟烟气，组成为5％O 2、1000ppmNO、 1000NH 3、5％H 2O，N 2为平衡气，空速为200000h -1。反应温度为200℃，NH 3/NO为1。气体成分由芬兰gasmet公司制造的Gasmet FTIR Dx4000烟气分析仪进行检测，检测的脱硝效率和选择性见表1。
表1
  MnO 2-CeO 2 V 2O 5-WO 3/TiO 2 混合催化剂(本发明)
脱硝效率(％) 46.08 24.4 92.7
选择性(％) 90.4 99.5 99.3
在本实施例中，发明人还对比了机械混合和压片成型分别得到的混合催化剂的效果(同等实验条件下测得)，其中机械混合后得到的混合催化剂脱硝效率为65.5％，压片成型得到的混合催化剂脱硝效率为92.7％，再次证明了本发明所述两者催化剂混合的协同效果，由于二者压片处理后接触面积更大，且接触距离更近，有利于中间产物亚硝酸盐的迁移和传质，因此混合催化剂的脱硝效率有了质的改进。
在具体实施方式一的基础上，进一步对上述混合协同强化型低温SCR脱硝催化剂的制备方法做限定，得到具体实施方式三，该方法具体步骤是：
1)将硝酸锰、硝酸铈和柠檬酸在35℃下搅拌使之溶于去离子水中，其中柠檬酸与金属盐的摩尔比为1.3：1，硝酸锰与硝酸铈的摩尔比为6:4，得到溶液；
2)将上述溶液加热至80℃并不停搅拌，直至溶液呈凝胶状，然后在烘箱中烘干，再在400℃温度条件下煅烧5h后，将催化剂研磨成颗粒度小于300目的粉末，得到催化剂A，另外取部分催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒作为对比样品；
3)将TiO 2在105℃温度下干燥12h，作为载体；
4)将偏钒酸铵、偏钨酸铵和钼酸铵在60℃温度下搅拌使之溶于草酸溶液中，得到pH值小于2的溶液；
5)将步骤3)得到的载体、步骤4)得到pH值小于2的溶液采用浸渍法混合搅拌均匀，利用超声波清洗仪超声震荡20min，再用水浴80℃边蒸干边搅拌10min，然后在烘箱中110℃下烘12h，再在600℃温度条件下煅烧，得到了V 2O 5-WO 3-MoO 3/TiO 2催化剂，以质量百分比计催化剂组成为：载体TiO 2 93％，活性组分V 2O 5 1％，活性组分WO 3 3％， 活性组分MoO 3 3％。将催化剂研磨成颗粒度小于300目的粉末，得到催化剂B，另外取部分催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒作为对比样品；
6)将1份催化剂A、1.5份催化剂B、5份pH为3的硝酸溶液、0.05份羧甲基纤维素混合在一起，放入球磨机中以200转/分钟的转速进行球磨混合2h，然后在烘箱中烘干，将催化剂磨成颗粒度为100-200目的粉末，放入压片机中进行压片，经压片成型即得到低温SCR脱硝催化剂，将制备的催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒。
催化剂活性试验 具体试验方法同具体实施方式二，检测的脱硝效率和选择性见表2。
表2
  MnO 2-CeO 2 V 2O 5-WO 3-MoO 3/TiO 2 混合催化剂
脱硝效率(％) 48.1 25.6 96.5
选择性(％) 85.2 99.1 99.0
由表2数据可知，在低温SCR反应过程(反应温度为200℃)中，氧化型催化剂形成的亚硝酸盐中间产物可快速与V 2O 5-WO 3-MoO 3/TiO 2催化剂中吸附的NH 3发生反应，大大降低了反应活化能，并大幅提高了催化剂的活性，同样条件下，该混合催化剂活性比两种单独的催化剂活性均提高了2倍以上。
在具体实施方式一的基础上，进一步对上述混合协同强化型低温SCR脱硝催化剂的制备方法做限定，得到具体实施方式四，该方法具体步骤是：
1)将硝酸钴、硝酸铈和柠檬酸在35℃下搅拌使之溶于去离子水中，其中柠檬酸与金属盐的摩尔比为1.2：1，硝酸钴与硝酸铈的摩尔比为3:7，得到溶液；
2)将上述溶液加热至80℃并不停搅拌，直至溶液呈凝胶状，然后在烘箱中烘干，再在500℃温度条件下煅烧3h后，将催化剂研磨成颗粒度小于300目的粉末，得到催化剂A，另外取部分催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒作为对比样品；
3)将TiO 2在105℃温度下干燥12h，作为载体；
4)将偏钒酸铵、偏钨酸铵和钼酸铵在60℃温度下搅拌使之溶于草酸溶液中，得到 pH值小于2的溶液；
5)将步骤3)得到的载体、步骤4)得到pH值小于2的溶液采用浸渍法混合搅拌均匀，利用超声波清洗仪超声震荡20min，再用水浴80℃边蒸干边搅拌10min，然后在烘箱中110℃下烘12h，再在600℃温度条件下煅烧，得到了V 2O 5-WO 3-MoO 3/TiO 2催化剂，以质量百分比计催化剂组成为：载体TiO 2 92％，活性组分V 2O 5 2％，活性组分WO 3 4％，活性组分MoO 3 2％。将催化剂研磨成颗粒度小于300目的粉末，得到催化剂B，另外取部分催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒作为对比样品；
6)将1份催化剂A、1份催化剂B、3份pH为3的硝酸溶液、0.05份羧甲基纤维素混合在一起，放入球磨机中以300转/分钟的转速进行球磨混合1h，然后在烘箱中烘干，将催化剂磨成颗粒度为100-200目的粉末，放入压片机中进行压片，经压片成型即得到低温SCR脱硝催化剂，将制备的催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒。
催化剂活性试验 具体试验方法同具体实施方式二，检测的脱硝效率和选择性见表3。
表3
  CoO 3-CeO 2 V 2O 5-WO 3-MoO 3/TiO 2 混合催化剂
脱硝效率(％) 41.8 32.5 93.6
选择性(％) 91.2 99.6 99.5
在具体实施方式一的基础上，进一步对上述混合协同强化型低温SCR脱硝催化剂的制备方法做限定，得到具体实施方五，该方法具体步骤是：
1)将硝酸钴、硝酸铈和柠檬酸在25℃下搅拌使之溶于去离子水中，其中柠檬酸与金属盐的摩尔比为1.5：1，硝酸钴与硝酸铈的摩尔比为9:1，得到溶液；
2)将上述溶液加热至80℃并不停搅拌，直至溶液呈凝胶状，然后在烘箱中烘干，再在450℃温度条件下煅烧3h后，将催化剂研磨成颗粒度小于300目的粉末，得到催化剂A，另外取部分催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒作为对比样品；
3)将TiO 2在105℃温度下干燥12h，作为载体；
4)将偏钒酸铵和钼酸铵在60℃温度下搅拌使之溶于草酸溶液中，得到pH值小于2的溶液；
5)将步骤3)得到的载体、步骤4)得到pH值小于2的溶液采用浸渍法混合搅拌均匀，利用超声波清洗仪超声震荡20min，再用水浴80℃边蒸干边搅拌10min，然后在烘箱中110℃下烘12h，再在600℃温度条件下煅烧，得到负载了V 2O 5-MoO 3/TiO 2催化剂，以质量百分比计催化剂组成为：载体TiO 2 94％，活性组分V 2O 5 1％，活性组分MoO 3 5％。将催化剂研磨成颗粒度小于300目的粉末，得到催化剂B，另外取部分催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒作为对比样品；
6)将1份催化剂A、2份催化剂B、5份pH为4的硝酸溶液、0.03份聚乙二醇混合在一起，放入球磨机中以200转/分钟的转速进行球磨混合2h，然后在烘箱中烘干，将催化剂磨成颗粒度为100-200目的粉末，放入压片机中进行压片，经压片成型即得到低温SCR脱硝催化剂，将制备的催化剂粉碎过筛，得到粒径为60目至40目之间的催化剂颗粒。
催化剂活性试验 具体试验方法同具体实施方式二，检测的脱硝效率和选择性见表4。
表4
  CoO 3-CeO 2 V 2O 5-MoO 3/TiO 2 混合催化剂
脱硝效率(％) 51.5 27.3 98.2
选择性(％) 83.2 99.5 99.1
综上，由表1-4的数据可知，在低温SCR反应过程中，氧化型催化剂形成的亚硝酸盐中间产物可快速与中温脱硝催化剂中吸附的NH 3发生反应，大大降低了反应活化能，并大幅提高了催化剂的活性，同样条件下，本发明所述混合催化剂活性比两种单独的催化剂活性均提高了2倍以上，具有显而易见的协同效果；相比于氧化型催化剂单独使用，其选择性得到了较大提高。
应用例
一种所述的混合协同强化型低温SCR脱硝催化剂在低温烟气脱硝方面的催化应用，所述的低温是150～250℃的温度范围内。以具体实施方式二制得的催化剂为例考察 不同温度下本催化剂的性能，试验方法参见前述催化剂活性试验，数据见表5。
表5 不同温度下的脱硝效率％
温度(℃) MnO 2-CeO 2 V 2O 5-WO 3/TiO 2 混合催化剂(本发明)
150 35.6 8.1 70.6
200 46.08 24.4 92.7
250 65.2 69.2 99.8
由表5的数据可知，本发明所述混合催化剂在低温情况仍然保持较好的脱硝效率，可实现150～250℃的温度范围内的应用，显而易见的温度越高催化活性越好，因此，其超过250℃的温度也必然适用。
对比例
为验证两种催化剂分别制备后混合与一次性制备含有相同催化活性物质的催化剂之间的效果区别，本试验例在前述试验的同等条件下分别制备了V 2O 5-MnO 2-WO 3/TiO 2催化剂，V 2O 5-CoO 3-WO 3/TiO 2催化剂和V 2O 5-CeO 2-WO 3/TiO 2催化剂，具体方法如下：
1)将TiO 2在105℃温度下干燥12h，作为载体；
2)将偏钒酸铵和偏钨酸铵在50℃温度下搅拌使之溶于草酸溶液中，然后将硝酸锰或者硝酸钴或者硝酸铈溶于草酸溶液中，得到pH值小于2的溶液；
3)将步骤1)得到的载体、步骤2)得到pH值小于2的溶液采用浸渍法混合搅拌均匀，利用超声波清洗仪超声震荡20min，再用水浴80℃边蒸干边搅拌10min，然后在烘箱中110℃下烘12h，再在500℃温度条件下煅烧，得到了V 2O 5-MnO 2-WO 3/TiO 2催化剂或V 2O 5-CoO 3-WO 3/TiO 2催化剂或V 2O 5-CeO 2-WO 3/TiO 2催化剂，以质量百分比计催化剂组成为：载体TiO 2 89％，活性组分V 2O 5 1％，活性组分WO 3 5％，活性组分MnO 2或CoO 3或CeO 25％。将催化剂研磨成粒径为60目至40目之间的催化剂颗粒；采用前述方法进行催化剂活性试验，结果见表6。
表6
  V 2O 5-WO 3/TiO 2 V 2O 5-MnO 2-WO 3/TiO 2 V 2O 5-CoO 3-WO 3/TiO 2 V 2O 5-CeO 2-WO 3/TiO 2
脱硝效率(％) 24.4 28.2 21.8 26.7
选择性(％) 99.5 97.5 99.5 96.2
按照理论分析，几种活性组分加在一起应是促进催化活性的，但是根据上述结果可知该促进作用不明显，V 2O 5-CoO 3-WO 3/TiO 2甚至活性更低，这说明多种(含两种)活性组分之间存在相互抑制作用，使得MnO 2，CoO 3或CeO 2的活性作用没有发挥出来。因此，当催化剂中含两种及以上活性组分时，活性组分之间相互影响产生副作用。
本说明书中各个实施例采用递进的方式描述，每个实施例重点说明的都是与其它实施例的不同之处，各个实施例之间相同或相似部分互相参见即可。对于实施例公开的装置而言，由于其与实施例公开的方法相对应，所以描述的比较简单，相关之处参见方法部分说明即可。
以上对本发明所提供的混合协同强化型低温SCR脱硝催化剂进行了详细介绍。本文中应用了具体个例对本发明的原理及实施方式进行了阐述，以上实施例的说明只是用于帮助理解本发明的方法及其核心思想。应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以对本发明进行若干改进和修饰，这些改进和修饰也落入本发明权利要求的保护范围内。

Claims (10)

  1. 一种混合协同强化型低温SCR脱硝催化剂，其特征在于：该催化剂是由两种催化剂混合而成，一种是氧化型催化剂MnO 2-CeO 2或CoO 3-CeO 2中的一种或两种任意比例的组合，MnO 2-CeO 2中MnO 2和CeO 2的摩尔比为任意比，CoO 3-CeO 2中CoO 3和CeO 2的摩尔比为任意比，另一种是中温脱硝催化剂V 2O 5-WO 3-MoO 3/TiO 2，其中V 2O 5的质量分数为0.5％～2％，WO 3的质量分数为0-5％，MoO 3的质量分数为0-5％；
    所述氧化型催化剂与中温脱硝催化剂的质量比为1：(0.5～3)。
  2. 根据权利要求1所述的混合协同强化型低温SCR脱硝催化剂，其特征在于：将氧化型催化剂与中温脱硝催化剂以及适量pH为3～4的硝酸溶液、粘结剂混合研磨，烘干，得到颗粒度为100～200目的催化剂粉末，机械压片成型即得到所述低温SCR脱硝催化剂。
  3. 根据权利要求2所述的混合协同强化型低温SCR脱硝催化剂，其特征在于：该混合协同强化型低温SCR脱硝催化剂中，以氧化型催化剂为1重量份计，pH为3～4的硝酸溶液用量为3～5重量份、粘结剂用量为0.02～0.05重量份。
  4. 根据权利要求1所述的混合协同强化型低温SCR脱硝催化剂，其特征在于：MnO 2-CeO 2中MnO 2和CeO 2的摩尔比为5:5～6:4，CoO 3-CeO 2中CoO 3和CeO 2的摩尔比为8:2～9:1。
  5. 根据权利要求1所述的混合协同强化型低温SCR脱硝催化剂，其特征在于：所述氧化型催化剂与中温脱硝催化剂的质量比为1：(1～2)。
  6. 根据权利要求1所述的混合协同强化型低温SCR脱硝催化剂，其特征在于：所述粘结剂为聚乙二醇或羧甲基纤维素中的一种或两种。
  7. 一种混合协同强化型低温SCR脱硝催化剂的制备方法，其特征在于：该方法包括如下步骤：
    步骤S101：氧化型催化剂的制备，
    步骤S102：中温脱硝催化剂的制备，
    步骤S103：两种催化剂的混合压片，
    将1重量份氧化型催化剂、0.5～2重量份中温脱硝催化剂、3～5重量份pH为3～4的硝酸溶液、0.02～0.05重量份粘结剂混合，球磨机中球磨1～2h，然后在200～250℃烘干，将催化剂磨成颗粒度为100～200目的粉末，机械压片成型，即得到低温SCR脱硝 催化剂。
  8. 根据权利要求6所述的制备方法，其特征在于：步骤S101：氧化型催化剂的制备，
    1)将硝酸锰、硝酸铈和柠檬酸在25℃～35℃下搅拌使之溶于去离子水中，其中柠檬酸与金属盐的摩尔比为1.2～1.5:1，得到溶液A；
    或将硝酸钴、硝酸铈和柠檬酸在25℃～35℃下搅拌使之溶于去离子水中，其中柠檬酸与金属盐的摩尔比为1.2～1.5:1，得到溶液B；
    2)将溶液A或溶液B加热至75～85℃并不停搅拌，直至溶液呈凝胶状，然后在烘箱中烘干，再在400℃～500℃温度条件下煅烧3～5h后，将催化剂研磨成颗粒度小于300目的粉末，得到氧化型催化剂。
  9. 根据权利要求6所述的制备方法，其特征在于：步骤S102：中温脱硝催化剂的制备，TiO 2干燥后作为载体，
    将偏钒酸铵、偏钨酸铵和钼酸铵在50℃～70℃温度下搅拌使之溶于草酸溶液中，得到pH值小于2的溶液D；
    将TiO 2载体浸渍于溶液D中搅拌均匀，超声震荡，再用水浴边蒸干边搅拌10～60min，然后在烘箱中烘干，再在500℃～600℃温度条件下煅烧3～5h后，将催化剂研磨成颗粒度小于300目的粉末，得到中温脱硝催化剂。
  10. 一种权利要求1所述的混合协同强化型低温SCR脱硝催化剂在低温烟气脱硝方面的催化应用，其特征在于所述的低温是150～250℃的温度范围内。
PCT/CN2021/080079 2020-03-11 2021-03-10 一种混合协同强化型低温scr脱硝催化剂及其制备方法 Ceased WO2021180142A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010166619.5A CN111282569B (zh) 2020-03-11 2020-03-11 一种混合协同强化型低温scr脱硝催化剂及其制备方法
CN202010166619.5 2020-03-11

Publications (1)

Publication Number Publication Date
WO2021180142A1 true WO2021180142A1 (zh) 2021-09-16

Family

ID=71018123

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/080079 Ceased WO2021180142A1 (zh) 2020-03-11 2021-03-10 一种混合协同强化型低温scr脱硝催化剂及其制备方法

Country Status (2)

Country Link
CN (1) CN111282569B (zh)
WO (1) WO2021180142A1 (zh)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113926466A (zh) * 2021-11-23 2022-01-14 商河县格尔环保科技服务中心 一种脱硝催化剂及其制备方法
CN114146721A (zh) * 2021-12-01 2022-03-08 通化鑫鸿新材料有限公司 一种以生物质炭粉为载体的复合脱硝剂及其制备方法和应用
CN116651436A (zh) * 2023-05-04 2023-08-29 安徽元琛环保科技股份有限公司 一种抗水耐硫超低温条状脱硝催化剂及其制备方法
CN117244560A (zh) * 2023-09-21 2023-12-19 哈尔滨工业大学(深圳)(哈尔滨工业大学深圳科技创新研究院) 一种抗硫水型Mn基低温脱硝催化剂及其制备方法和应用
CN117861669A (zh) * 2024-01-05 2024-04-12 陕西煤业化工技术研究院有限责任公司 一种稀土铁氧体型脱硝催化剂及其制备方法
CN118925789A (zh) * 2024-10-11 2024-11-12 绍兴文理学院 一种固相高速高压球磨法一步合成耐重金属和硫中毒的脱硝协同脱除co/ch多功能催化剂及其应用
CN120393996A (zh) * 2025-02-26 2025-08-01 浙江大学 一种协同脱硝脱含氯有机物的复合催化剂及其制备方法和应用
CN121423042A (zh) * 2026-01-05 2026-01-30 西南石油大学 一种改性载体催化剂的制备方法及其在聚光催化甲烷硫化氢重整反应中的应用

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111282569B (zh) * 2020-03-11 2021-04-02 浙江大学 一种混合协同强化型低温scr脱硝催化剂及其制备方法
CN114377670B (zh) * 2021-12-10 2023-06-20 浙江大学 用于低温scr脱硝的复合型金属氧化物催化剂及其制备方法
CN114307634A (zh) * 2022-01-05 2022-04-12 嘉兴沃特泰科环保科技股份有限公司 颗粒态脱硝剂及其制备方法和应用

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105664924A (zh) * 2016-01-13 2016-06-15 南京大学 形貌效应强化低温活性的脱硝催化剂及其制备方法和应用
CN111282569A (zh) * 2020-03-11 2020-06-16 浙江大学 一种混合协同强化型低温scr脱硝催化剂及其制备方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103785409B (zh) * 2014-02-19 2015-12-02 哈尔滨工程大学 一种超声与分步浸渍法制备低温脱硝复合催化剂的方法
CN105413705A (zh) * 2015-11-11 2016-03-23 福建紫荆环境工程技术有限公司 一种光催化协同热催化氧化去除VOCs的催化剂及其制备方法和应用
CN107497482A (zh) * 2016-12-29 2017-12-22 廊坊市北辰创业树脂材料有限公司 一种新型低温复合催化剂的制备和应用
CN108404931B (zh) * 2018-05-16 2020-04-28 江苏浩日朗环保科技有限公司 复合scr脱硝催化剂及其制备方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105664924A (zh) * 2016-01-13 2016-06-15 南京大学 形貌效应强化低温活性的脱硝催化剂及其制备方法和应用
CN111282569A (zh) * 2020-03-11 2020-06-16 浙江大学 一种混合协同强化型低温scr脱硝催化剂及其制备方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SALAZAR MARIAM, HOFFMANN STEFANIE, TKACHENKO OLGA P., BECKER RALF, GRÜNERT WOLFGANG: "Hybrid catalysts for the selective catalytic reduction of NO by NH 3 : The influence of component separation on the performance of hybrid systems", APPLIED CATALYSIS B. ENVIRONMENTAL, vol. 182, 1 March 2016 (2016-03-01), pages 213 - 219, XP055845567, ISSN: 0926-3373, DOI: 10.1016/j.apcatb.2015.09.028 *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113926466A (zh) * 2021-11-23 2022-01-14 商河县格尔环保科技服务中心 一种脱硝催化剂及其制备方法
CN114146721A (zh) * 2021-12-01 2022-03-08 通化鑫鸿新材料有限公司 一种以生物质炭粉为载体的复合脱硝剂及其制备方法和应用
CN114146721B (zh) * 2021-12-01 2024-04-19 通化鑫鸿新材料有限公司 一种以生物质炭粉为载体的复合脱硝剂及其制备方法和应用
CN116651436A (zh) * 2023-05-04 2023-08-29 安徽元琛环保科技股份有限公司 一种抗水耐硫超低温条状脱硝催化剂及其制备方法
CN117244560A (zh) * 2023-09-21 2023-12-19 哈尔滨工业大学(深圳)(哈尔滨工业大学深圳科技创新研究院) 一种抗硫水型Mn基低温脱硝催化剂及其制备方法和应用
CN117861669A (zh) * 2024-01-05 2024-04-12 陕西煤业化工技术研究院有限责任公司 一种稀土铁氧体型脱硝催化剂及其制备方法
CN118925789A (zh) * 2024-10-11 2024-11-12 绍兴文理学院 一种固相高速高压球磨法一步合成耐重金属和硫中毒的脱硝协同脱除co/ch多功能催化剂及其应用
CN120393996A (zh) * 2025-02-26 2025-08-01 浙江大学 一种协同脱硝脱含氯有机物的复合催化剂及其制备方法和应用
CN121423042A (zh) * 2026-01-05 2026-01-30 西南石油大学 一种改性载体催化剂的制备方法及其在聚光催化甲烷硫化氢重整反应中的应用

Also Published As

Publication number Publication date
CN111282569A (zh) 2020-06-16
CN111282569B (zh) 2021-04-02

Similar Documents

Publication Publication Date Title
WO2021180142A1 (zh) 一种混合协同强化型低温scr脱硝催化剂及其制备方法
CN101920213B (zh) 以金属有机框架物为载体的低温scr脱硝催化剂及其制备方法
CN103990496B (zh) 一种具有抗中毒性能的中低温scr脱硝催化剂及其制备方法
CN100542670C (zh) 一种烟气脱硝中的低温多组分催化剂及其制备方法
CN103638942A (zh) 一种用于水泥窑低温烟气脱硝的scr催化剂及其制备方法
CN101676019B (zh) 一种氨气选择性催化还原(scr)电厂烟气低温脱硝的催化剂及其制备方法
CN105833901B (zh) 一种PrOx-MnOx/SAPO-34低温SCR烟气脱硝催化剂及其制备方法与应用
CN101507928A (zh) 一种铁锰复合氧化物催化剂及其制备方法和应用
CN103706390B (zh) 一种用于催化氧化no的钛基载体负载钒磷氧化物催化剂及其制备方法
CN102166522A (zh) 一种烟气脱硝催化剂及其制备和应用
CN111992203A (zh) 一种nh3-scr低温脱硝催化剂及其制备方法与应用
CN105214670B (zh) 以原铁矿石为载体的中低温负载型脱硝催化剂的制备及测试方法
CN111229208A (zh) 一种荷叶源生物炭负载金属氧化物的低温scr烟气脱硝催化剂及其制备方法与应用
CN110841653B (zh) 一种低温脱硝催化剂的制备方法
CN112844366A (zh) 抗多重中毒的nh3-scr催化剂及其制备方法
CN108187661A (zh) 一种具有抗高浓度k中毒性能的中高温scr脱硝催化剂及其制备方法
CN108246282A (zh) 一种中低温scr脱硝催化剂及其制备方法
CN106582874A (zh) 一种耐高温磷钨酸吸附型铁基氧化物催化剂及其制备方法
CN111905721A (zh) 二氧化钛纳米阵列低温脱硝脱汞用催化剂及制备方法
CN103055889A (zh) 一种低温脱硝MnOx-CuO-TiO2催化剂及其制备方法和应用
CN101367046B (zh) 一种用于去除氮氧化物的阴离子修饰催化剂的制备方法
CN109012680A (zh) 一种用于烟气脱硝的催化剂及其制备方法和应用
CN107433204A (zh) 同时还原烟气中二氧化硫和氮氧化物的负载型铁基催化剂及其制备方法与应用
CN108236943A (zh) 一种钒基氧化物催化剂的制备方法
CN105498799A (zh) 铁锰钛复合金属氧化物脱硝催化剂及其制备方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21766958

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21766958

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 21766958

Country of ref document: EP

Kind code of ref document: A1

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 06/06/2023)