CN111569866A - Low-temperature SCR denitration catalyst and preparation method thereof - Google Patents

Low-temperature SCR denitration catalyst and preparation method thereof Download PDF

Info

Publication number
CN111569866A
CN111569866A CN202010522694.0A CN202010522694A CN111569866A CN 111569866 A CN111569866 A CN 111569866A CN 202010522694 A CN202010522694 A CN 202010522694A CN 111569866 A CN111569866 A CN 111569866A
Authority
CN
China
Prior art keywords
low
scr denitration
salt
denitration catalyst
temperature
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.)
Pending
Application number
CN202010522694.0A
Other languages
Chinese (zh)
Inventor
王建成
史建强
王兵
王美鑫
胡江亮
姚俊轩
鲍卫仁
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.)
Taiyuan University of Technology
Original Assignee
Taiyuan University of Technology
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 Taiyuan University of Technology filed Critical Taiyuan University of Technology
Priority to CN202010522694.0A priority Critical patent/CN111569866A/en
Publication of CN111569866A publication Critical patent/CN111569866A/en
Pending legal-status Critical Current

Links

Images

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
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/32—Manganese, technetium or rhenium
    • B01J23/34—Manganese
    • 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
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/206—Ammonium compounds
    • B01D2251/2062—Ammonia
    • 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

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (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

The invention provides a low-temperature SCR denitration catalyst and a preparation method thereof, wherein the low-temperature SCR denitration catalyst comprises manganese, cerium, samarium and titanium, wherein the molar ratio of the manganese to the cerium to the samarium to the titanium is Mn: Ce: Sm: Ti (0.1-1): 0.1-0.5): 4. The low-temperature SCR denitration catalyst prepared by the invention shows good NH in the range of 140 ℃ and 400 DEG C3Selectively reducing NO activity and having stable sulfur resistance and water resistance.

Description

Low-temperature SCR denitration catalyst and preparation method thereof
Technical Field
The invention relates to the field of denitration catalysts, in particular to a sulfur-resistant and water-resistant low-temperature SCR denitration catalyst and a preparation method thereof.
Background
Coal is an important part of energy structures in China, and has absolute advantages in quantity. In China, coal accounts for over 70 percent of primary energy, and for the national energy consumption pattern, coal occupies an important position, the important position of coal does not change in the future for a long time, a large amount of coal is combusted to bring serious environmental pollution to China, and NO generated at the same timexPollutants bring a plurality of environmental problems such as acid rain, photochemical smog and the like, influence human living and are always highly concerned by countries in the world.
The most widely used denitration method is Selective Catalytic Reduction (SCR) in which NO is reduced with a reducing agent (hydrocarbons, hydrogen and ammonia)xReduction to N harmless to atmosphere2Because of its high denitration efficiency and good selectivity, it has been widely used.
The most widely used SCR catalyst at present is V2O5-WO3/TiO2The catalyst has been applied to the fields of power plants, cement plants, glass kilns, steel plants and the like. However, the working temperature of the traditional SCR is above 300 ℃, and the SCR device needs to be arranged before desulfurization and dust removal so as to avoid repeatedly heating the flue gas. At this temperature, SO in the flue gas2And dust can lead to deactivation of the catalyst. If the SCR device is arranged at the tail end, the SCR device needs to be reheated, and energy consumption is increased. At the same time, V2O5Has great harm to human and environment.
The working temperature of the catalyst in the low-temperature SCR technology is generally 100-300 ℃, and the SCR device can be placed after desulfurization and dust removal, thereby avoiding SO in flue gas2And the interference of dust, compared with the traditional SCR, the SCR has higher economical practicability and is beneficial to popularization.
Chinese patent application CN201811441127.1 discloses a method for improving water resistance and sulfur resistance of a manganese-based low-temperature SCR denitration catalyst, which adopts hydrophobic polytetrafluoroethylene as a coating or dopant, and the hydrophobic polytetrafluoroethylene and the manganese-based catalyst are simply dispersed in a reactor filled with absolute ethyl alcohol, and are mixed, stirred, filtered, dried and calcined to prepare the manganese-based low-temperature SCR denitration catalyst with excellent water resistance and sulfur resistanceA catalyst. The catalyst prepared by the method has NO at 160 DEG CxThe conversion rate is below 70%, and the denitration efficiency is low.
Therefore, how to improve the NO conversion rate and N of the low-temperature SCR denitration catalyst2The selectivity, water resistance and sulfur resistance have become the hot spots and difficulties of the technical research in the field.
Disclosure of Invention
In view of the above problems, the present invention provides a NOxConversion, N2A low-temperature SCR denitration catalyst with high selectivity, water resistance and sulfur resistance and a preparation method thereof.
The invention aims to provide a low-temperature SCR denitration catalyst which comprises manganese, cerium, samarium and titanium, wherein the molar ratio of the manganese to the cerium to the samarium to the titanium is Mn: Ce: Sm: Ti (0.1-1): 0.1-0.5): 4.
Preferably, the molar ratio of manganese, cerium, samarium and titanium is Mn: Ce: Sm: Ti ═ 1:0.5 (0.1-0.5): 4.
More preferably, the molar ratio of manganese, cerium, samarium and titanium is Mn: Ce: Sm: Ti ═ 1:0.5:0.3: 4.
Preferably, the low-temperature SCR denitration catalyst is a porous mixed metal oxide nanoparticle.
Another object of the present invention is to provide a method for preparing a low-temperature SCR denitration catalyst, comprising the following steps:
(1) dissolving manganese salt, cerium salt, samarium salt and titanium salt in deionized water to obtain a mixed solution A;
(2) adding polyethylene glycol into the mixed solution A, heating and stirring to obtain a mixed solution B;
(3) adding an alkaline solution into the mixed solution B, adjusting the pH value, and stirring to obtain a mixed solution C;
(4) aging the mixed solution C in a closed container to obtain an intermediate product;
(5) and cooling the intermediate product, and carrying out solid-liquid separation, washing, drying and roasting to obtain the low-temperature SCR denitration catalyst.
Preferably, in the step (1), the molar ratio of the manganese salt, the cerium salt, the samarium salt and the titanium salt is Mn: Ce: Sm: Ti (0.1-1): 0.1-0.5): 4.
More preferably, in step (1), the molar ratio of manganese salt, cerium salt, samarium salt and titanium salt is Mn: Ce: Sm: Ti ═ 1:0.5 (0.1-0.5): 4.
Further preferably, in the step (1), the molar ratio of the manganese salt, the cerium salt, the samarium salt and the titanium salt is Mn: Ce: Sm: Ti ═ 1:0.5:0.3: 4.
Preferably, in step (1), the manganese salt is manganese nitrate and/or manganese acetate; the cerium salt is cerium nitrate and/or cerium acetate; the samarium salt is samarium nitrate and/or samarium acetate; the titanium salt is titanium sulfate and/or tetrabutyl titanate.
More preferably, in step (1), the manganese salt, cerium salt, samarium salt and titanium salt are respectively manganese nitrate, cerium nitrate, samarium nitrate and titanium sulfate, wherein the manganese nitrate is 50 wt.% manganese nitrate in water.
Preferably, in the step (2), the heating and stirring temperature is 25-40 ℃, and the heating time is 30-60 min.
Preferably, in the step (3), the pH is adjusted to 10-12; the stirring time is 5-8 h. The alkaline solution is preferably ammonia.
Preferably, in the step (4), the aging temperature is 100-120 ℃, and the aging time is 24-36 h.
Preferably, in the step (5), the drying temperature is 100-130 ℃, and the drying time is 11-14 h.
Preferably, in the step (5), the roasting temperature is 500-600 ℃, and the roasting time is 5-8 h.
According to the low-temperature SCR denitration catalyst provided by the technical scheme of the invention, Mn with excellent low-temperature activity is used for replacing a toxic element V, and lanthanide elements Sm and Ce are introduced, so that the dispersity of the catalyst is improved, and the synergistic effect of the components Mn, Ce, Sm and Ti is increased, thereby improving the catalytic activity of the catalyst. In addition, in the technical scheme of the invention, Ce is simultaneously used as a sacrificial site to reduce sulfation of a main active phase, SO that the SO of the catalyst is improved at the cost of Ce2The resistance of (1).
Compared with the prior art, the invention has the following beneficial effects:
(1) the preparation method is simple, convenient to operate, wide in application prospect and suitable for industrial mass production.
(2) The low-temperature SCR denitration catalyst prepared by the invention shows good NH in the range of 140 ℃ and 400 DEG C3Selectively reducing NO activity and having stable sulfur resistance and water resistance.
(3) The active component of the low-temperature SCR denitration catalyst prepared by the invention does not contain V component, the sublimation and falling of the active component and the toxicity of the inactivated catalyst in the denitration process are reduced, and the low-temperature SCR denitration catalyst is environment-friendly and environment-friendly.
Drawings
To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, and it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope of the present invention.
FIG. 1 is a graph showing NO conversion rates of low-temperature SCR denitration catalysts prepared in examples 1 to 4 of the present invention and comparative examples 1 to 4;
FIG. 2 shows N of low-temperature SCR denitration catalysts prepared in examples 1 to 4 of the present invention and comparative examples 1 to 42A plot of selectivity;
FIG. 3 shows that 5% H is introduced into the low-temperature SCR denitration catalysts prepared in examples 1 to 4 and comparative examples 1 to 4 of the present invention at 160 ℃2O、200ppm SO2A plot of NO conversion of (a);
fig. 4 is HRTEM images of the low-temperature SCR denitration catalysts prepared in example 3 of the present invention and comparative examples 1 to 3.
Detailed Description
The terms as used herein:
the terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.
When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1-5" is disclosed, the described range should be interpreted to include the ranges "1-4", "1-3", "1-2 and 4-5", "1-3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.
"and/or" is used to indicate that one or both of the illustrated conditions may occur, e.g., a and/or B includes (a and B) and (a or B).
One embodiment of the invention provides a low-temperature SCR denitration catalyst, which comprises manganese, cerium, samarium and titanium, wherein the molar ratio of the manganese to the cerium to the samarium to the titanium is Mn: Ce: Sm: Ti (0.1-1): (0.1-0.5): 4.
Preferably, the molar ratio of manganese, cerium, samarium and titanium is Mn: Ce: Sm: Ti ═ 1:0.5 (0.1-0.5): 4.
More preferably, the molar ratio of manganese, cerium, samarium and titanium is Mn: Ce: Sm: Ti ═ 1:0.5:0.3: 4.
Preferably, the low-temperature SCR denitration catalyst is a porous mixed metal oxide nanoparticle.
Another embodiment of the present invention provides a preparation method of a low-temperature SCR denitration catalyst, including the steps of:
(1) dissolving manganese salt, cerium salt, samarium salt and titanium salt in deionized water to obtain a mixed solution A;
preferably, the molar ratio of manganese salt, cerium salt, samarium salt and titanium salt is Mn: Ce: Sm: Ti ═ 0.1-1: 0.1-0.5: 4;
in a preferred embodiment, the molar ratio of manganese salt, cerium salt, samarium salt and titanium salt is Mn: Ce: Sm: Ti ═ 1:0.5 (0.1-0.5): 4;
as a specific embodiment, the molar ratio of manganese salt, cerium salt, samarium salt and titanium salt is Mn: Ce: Sm: Ti is 1:0.5:0.3: 4;
preferably, the manganese salt is manganese nitrate and/or manganese acetate; the cerium salt is cerium nitrate and/or cerium acetate; the samarium salt is samarium nitrate and/or samarium acetate; the titanium salt is titanium sulfate and/or tetrabutyl titanate; the metal salts have good solubility, are easy to dissolve, are beneficial to the synergistic action of the components of Mn, Ce, Sm and Ti and are beneficial to the structural form control of the catalyst;
as a specific embodiment, the manganese salt, cerium salt, samarium salt and titanium salt are respectively manganese nitrate, cerium nitrate, samarium nitrate and titanium sulfate, wherein the manganese nitrate is 50 wt.% manganese nitrate in water.
(2) Adding polyethylene glycol into the mixed solution A obtained in the step (1), heating and stirring to obtain a mixed solution B;
as a preferred embodiment, in the step, the heating and stirring temperature is 25-40 ℃, and the heating time is 30-60 min; the addition of the polyethylene glycol is beneficial to promoting the catalyst to obtain larger specific surface area, so that the contact area required by catalytic reaction is provided, the utilization rate of active components is improved, the absorption of gas is facilitated, and the catalytic activity of the catalyst is improved; in addition, the polyethylene glycol has good water solubility, is favorable for improving the dispersibility of metal salt when used as a template agent, and is environment-friendly and non-toxic;
(3) adding an alkaline solution into the mixed solution B obtained in the step (2), adjusting the pH value, and stirring to obtain a mixed solution C;
as a preferred embodiment, in this step, the pH is adjusted to 10 to 12; the stirring time is 5-8 h. The alkaline solution is preferably ammonia. The pH is adjusted by ammonia water, so that the introduction of other metal elements can be effectively prevented, and the control of catalyst components is facilitated;
(4) aging the mixed solution C obtained in the step (3) in a closed container to obtain an intermediate product;
as a preferred embodiment, in the step, the aging temperature is 100-120 ℃, and the aging time is 24-36 h; in the step, solid-phase reaction occurs, and the reasonable control of the aging temperature and time is beneficial to the formation of a special structure of a substance;
(5) and (4) cooling the intermediate product obtained in the step (4), and carrying out solid-liquid separation, washing, drying and roasting to obtain the low-temperature SCR denitration catalyst.
As a preferred embodiment, in the step, the drying temperature is 100-; the roasting temperature is 500-600 ℃, and the roasting time is 5-8 h. The template agent can be removed by baking.
The low-temperature SCR denitration catalyst provided by the embodiment of the invention comprises four metal components of Mn, Ce, Sm and Ti, wherein the Sm is beneficial to improving the dispersibility of the catalyst and increasing the synergistic effect of the components of Mn, Ce, Sm and Ti, so that the catalytic activity is improved, but excessive Sm can cause the blockage of catalyst pore channels and cover MnO2Such that the activity of the catalyst is reduced; ce acts as a sacrificial site to mitigate sulfation of the major active phase, thereby increasing the SO-pair of the catalyst at the expense of Ce2The resistance of (1). The mesoporous nanostructure of the low-temperature SCR denitration catalyst promotes the contact and connection of mixed oxides, and is beneficial to the interaction of the mixed oxides and the transfer of adsorbed reactants. All of these factors contribute to the excellent catalytic activity of the mixed phase oxide catalyst and SO2And H2O tolerance and effectively increases the active temperature window of the catalyst.
Embodiments of the present invention will be described in detail below with reference to specific examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
Example 1
The embodiment provides a low-temperature SCR denitration catalyst MnCeSm (0.1) TiOxWherein the molar ratio of manganese, cerium, samarium and titanium is Mn: Ce: Sm: Ti: 1:0.5:0.1:4, the MnCeSm (0.1) TiOxThe low-temperature SCR denitration catalyst is porous mixed metal oxide nano particles.
This implementationExample MnCeSm (0.1) TiOxThe preparation method of the low-temperature SCR denitration catalyst comprises the following steps:
(1) heating 30mL of deionized water in a 50mL beaker to 25 ℃ under magnetic stirring, and adding 1.75mL of 50 wt.% Mn (NO) after the temperature is stabilized3)2Aqueous solution, 1.63g Ce (NO)3)2·6H2O，0.33g Sm(NO3)3·6H2O，7.2gTi(SO4)2Obtaining a mixed solution A;
(2) adding 1.78g of polyethylene glycol (PEG) into the mixed solution A obtained in the step (1), and stirring for 60min at 25 ℃ to obtain a mixed solution B;
(3) adding ammonia water into the mixed solution B obtained in the step (2), adjusting the pH to 10, and stirring at the rotating speed of 500r/min for 8 hours to obtain a mixed solution C;
(4) aging the mixed solution C obtained in the step (3) in a closed container at the aging temperature of 100 ℃ for 36h to obtain an intermediate product;
(5) cooling the intermediate product obtained in the step (4), performing solid-liquid separation, washing and filtering for multiple times by using deionized water, drying for 14 hours at 100 ℃, roasting for 8 hours at 500 ℃, tabletting and grinding to obtain 40-60-mesh MnCeSm (0.1) TiOxAnd (3) a low-temperature SCR denitration catalyst.
The prepared catalyst was tested for catalytic performance: 500ppm NH3，500ppm NO，5％O2Ar is balance gas, and the space velocity is 80000h-1. As shown in FIG. 1-2, the NO conversion rate reaches more than 89% when the reaction temperature is 140 ℃ and 400 ℃, and the N thereof2The selectivity reaches over 86 percent.
And (3) testing the water resistance and sulfur resistance of the prepared catalyst: SO is introduced into the simulated flue gas2And water vapor, SO2The concentration was 200ppm, the water vapor volume ratio was 5%, the other test conditions were unchanged, and the reaction temperature was 160 ℃. Under the test condition, the denitration efficiency of the catalyst is still stabilized to be more than 70% (as shown in figure 3), and the MnCeSm (0.1) TiOx catalyst is proved to have stronger water resistance and sulfur resistance.
Example 2
The embodiment is providedProvides a low-temperature SCR denitration catalyst MnCeSm (0.2) TiOxWherein the molar ratio of manganese, cerium, samarium and titanium is Mn: Ce: Sm: Ti: 1:0.5:0.2:4, the MnCeSm (0.2) TiOxThe low-temperature SCR denitration catalyst is porous mixed metal oxide nano particles.
MnCeSm (0.2) TiO of this examplexThe preparation method of the low-temperature SCR denitration catalyst comprises the following steps:
(1) heating 30mL of deionized water in a 50mL beaker to 30 ℃ under magnetic stirring, and adding 1.75mL of 50 wt.% Mn (NO) after the temperature is stabilized3)2Aqueous solution, 1.63g Ce (NO)3)2·6H2O，0.67g Sm(NO3)3·6H2O，7.2gTi(SO4)2Obtaining a mixed solution A;
(2) adding 1.53g of PEG into the mixed solution A obtained in the step (1), and stirring for 50min at 30 ℃ to obtain a mixed solution B;
(3) adding ammonia water into the mixed solution B obtained in the step (2), adjusting the pH to 11, and stirring for 6 hours at the rotating speed of 500r/min to obtain a mixed solution C;
(4) aging the mixed solution C obtained in the step (3) in a closed container at the aging temperature of 110 ℃ for 30h to obtain an intermediate product;
(5) cooling the intermediate product obtained in the step (4), performing solid-liquid separation, washing and filtering for multiple times by using deionized water, drying for 13h at 110 ℃, roasting for 6h at 550 ℃, tabletting and grinding to obtain 40-60-mesh MnCeSm (0.2) TiOxAnd (3) a low-temperature SCR denitration catalyst.
The prepared catalyst was tested for catalytic performance: 500ppm NH3，500ppm NO，5％O2Ar is balance gas, and the space velocity is 80000h-1. As shown in FIG. 1-2, the NO conversion rate reaches over 88% when the reaction temperature is 140 ℃ and 400 ℃, and the N thereof2The selectivity reaches more than 94 percent.
And (3) testing the water resistance and sulfur resistance of the prepared catalyst: SO is introduced into the simulated flue gas2And water vapor, SO2Concentration of 200ppm, water vapor volume ratio of 5%, other test conditions were unchanged, andthe temperature should be 160 ℃. Under the test condition, the denitration efficiency of the catalyst is still stabilized to be more than 72 percent (as shown in figure 3), and the MnCeSm (0.2) TiO is provedxThe catalyst has stronger water-resistant and sulfur-resistant capabilities.
Example 3
The embodiment provides a low-temperature SCR denitration catalyst MnCeSm (0.3) TiOxWherein the molar ratio of manganese, cerium, samarium and titanium is Mn: Ce: Sm: Ti: 1:0.5:0.3:4, the MnCeSm (0.3) TiOxThe low-temperature SCR denitration catalyst is porous mixed metal oxide nano particles.
MnCeSm (0.3) TiO of this examplexThe preparation method of the low-temperature SCR denitration catalyst comprises the following steps:
(1) heating 30mL of deionized water in a 50mL beaker to 35 ℃ under magnetic stirring, and adding 1.75mL of 50 wt.% Mn (NO) after the temperature is stabilized3)2Aqueous solution, 1.63g Ce (NO)3)2·6H2O，1.0g Sm(NO3)3·6H2O，7.2gTi(SO4)2Obtaining a mixed solution A;
(2) adding 1.88g of PEG into the mixed solution A obtained in the step (1), and stirring at 35 ℃ for 40min to obtain a mixed solution B;
(3) adding ammonia water into the mixed solution B obtained in the step (2), adjusting the pH to 11, and stirring at the rotating speed of 500r/min for 7 hours to obtain a mixed solution C;
(4) aging the mixed solution C obtained in the step (3) in a closed container at the aging temperature of 110 ℃ for 30h to obtain an intermediate product;
(5) cooling the intermediate product obtained in the step (4), performing solid-liquid separation, washing and filtering for multiple times by using deionized water, drying at 120 ℃ for 12 hours, roasting at 550 ℃ for 7 hours, tabletting and grinding to obtain 40-60-mesh MnCeSm (0.3) TiOxAnd (3) a low-temperature SCR denitration catalyst.
The prepared catalyst was tested for catalytic performance: 500ppm NH3，500ppm NO，5％O2Ar is balance gas, and the space velocity is 80000h-1. It was found by detection (as shown in FIG. 1-2) that the NO conversion rate reached 96% at the reaction temperature of 140 ℃ and 400 DEG CTo N thereof2The selectivity reaches more than 92 percent.
And (3) testing the water resistance and sulfur resistance of the prepared catalyst: SO is introduced into the simulated flue gas2And water vapor, SO2The concentration was 200ppm, the water vapor volume ratio was 5%, the other test conditions were unchanged, and the reaction temperature was 160 ℃. Under the test condition, the denitration efficiency of the catalyst is still stabilized to be more than 80% (as shown in figure 3), and the MnCeSm (0.3) TiO is provedxThe catalyst has stronger water-resistant and sulfur-resistant capabilities.
Example 4
The embodiment provides a low-temperature SCR denitration catalyst MnCeSm (0.5) TiOxWherein the molar ratio of manganese, cerium, samarium and titanium is Mn: Ce: Sm: Ti: 1:0.5:0.5:4, the MnCeSm (0.5) TiOxThe low-temperature SCR denitration catalyst is porous mixed metal oxide nano particles.
MnCeSm (0.5) TiO of this examplexThe preparation method of the low-temperature SCR denitration catalyst comprises the following steps:
(1) heating 30mL of deionized water in a 50mL beaker to 40 ℃ under magnetic stirring, and adding 1.75mL of 50 wt.% Mn (NO) after the temperature is stabilized3)2Aqueous solution, 1.63g Ce (NO)3)2·6H2O，1.67g Sm(NO3)3·6H2O，7.2gTi(SO4)2Obtaining a mixed solution A;
(2) adding 1.98g of PEG into the mixed solution A obtained in the step (1), and stirring for 30min at 40 ℃ to obtain a mixed solution B;
(3) adding ammonia water into the mixed solution B obtained in the step (2), adjusting the pH to 12, and stirring for 5 hours at the rotating speed of 500r/min to obtain a mixed solution C;
(4) aging the mixed solution C obtained in the step (3) in a closed container at the aging temperature of 120 ℃ for 24h to obtain an intermediate product;
(5) cooling the intermediate product obtained in the step (4), performing solid-liquid separation, washing and filtering for multiple times by using deionized water, drying for 11h at 130 ℃, roasting for 5h at 600 ℃, tabletting and grinding to obtain 40-60-mesh MnCeSm (0.5) TiOxLow-temperature SCR denitration catalyst。
The prepared catalyst was tested for catalytic performance: 500ppm NH3，500ppm NO，5％O2Ar is balance gas, and the space velocity is 80000h-1. As shown in FIG. 1-2, the NO conversion rate reaches over 86% when the reaction temperature is 140 ℃ and 400 ℃, and the N content thereof is2The selectivity reaches over 88 percent.
And (3) testing the water resistance and sulfur resistance of the prepared catalyst: SO is introduced into the simulated flue gas2And water vapor, SO2The concentration was 200ppm, the water vapor volume ratio was 5%, the other test conditions were unchanged, and the reaction temperature was 160 ℃. Under the test condition, the denitration efficiency of the catalyst is still stabilized to be more than 67 percent (as shown in figure 3), and the MnCeSm (0.5) TiO is provedxThe catalyst has stronger water-resistant and sulfur-resistant capabilities.
Comparative example 1
The comparative example provides a low-temperature SCR denitration catalyst MnCeTiOxThe catalyst is different from example 3 only in that the low-temperature SCR denitration catalyst of the comparative example does not contain Sm, and the molar ratios of the other three components Mn, Ce and Ti are the same as those of example 3; accordingly, in the preparation method of the low-temperature SCR denitration catalyst of the comparative example, Sm (NO) is not added3)3·6H2O, the remaining steps and the relevant parameters are the same as in example 3.
The prepared catalyst was tested for catalytic performance: 500ppm NH3，500ppm NO，5％O2Ar is balance gas, and the space velocity is 80000h-1. It was found by detection (as shown in FIG. 1-2) that the NO conversion rate was reduced to 83% at a reaction temperature of 140 ℃ and 400 ℃ and that N was2The selectivity is reduced to 80%. As can be seen, the Sm-deficient three-way catalyst MnCeTiOxThe catalytic activity of (a) is significantly reduced.
And (3) testing the water resistance and sulfur resistance of the prepared catalyst: SO is introduced into the simulated flue gas2And water vapor, SO2The concentration was 200ppm, the water vapor volume ratio was 5%, the other test conditions were unchanged, and the reaction temperature was 160 ℃. Under this test condition, the denitration efficiency of the catalyst was reduced to 55% (see fig. 3). As can be seen, the Sm-deficient three-way catalyst MnCeTiOxThe water-resistant and sulfur-resistant capability of the product is obviously reduced.
This is because the dispersibility of Sm, Mn, Ce and Ti by default is reduced and the synergy of the components is reduced, thereby resulting in a reduction in the catalytic activity and water-and sulfur-resistance of the catalyst. In addition, Sm inhibits the adsorption of electrons from adsorbed SO2To Mn4+Thereby hindering SO from being transferred2Oxidation to SO3Thereby reducing the deposition rate of sulfate species, thus the Sm default three-way catalyst MnCeTiOxThe NO conversion rate and the water and sulfur resistance are obviously reduced, and the temperature window is also reduced to 200-350 ℃.
Comparative example 2
The comparative example provides a low-temperature SCR denitration catalyst MnSmTiOxThe catalyst is different from example 3 only in that the low-temperature SCR denitration catalyst of the comparative example does not contain Ce, and the molar ratio of the other three components of Mn, Sm and Ti is the same as that of example 3; accordingly, in the preparation method of the low-temperature SCR denitration catalyst of the present comparative example, Ce (NO) was not added3)2·6H2O, the remaining steps and the relevant parameters are the same as in example 3.
The prepared catalyst was tested for catalytic performance: 500ppm NH3，500ppm NO，5％O2Ar is balance gas, and the space velocity is 80000h-1. It was found by detection (as shown in FIG. 1-2) that the NO conversion rate decreased to 78% at the reaction temperature of 140 ℃ and 400 ℃ and that N was2The selectivity dropped to 86%. As can be seen, the Ce-deficient three-way catalyst MnSmTiOxThe catalytic activity of (a) is significantly reduced.
And (3) testing the water resistance and sulfur resistance of the prepared catalyst: SO is introduced into the simulated flue gas2And water vapor, SO2The concentration was 200ppm, the water vapor volume ratio was 5%, the other test conditions were unchanged, and the reaction temperature was 160 ℃. Under this test condition, the denitration efficiency of the catalyst dropped to 52% (see fig. 3). As can be seen, the Ce-deficient three-way catalyst MnSmTiOxThe water resistance and sulfur resistance of the product are obviously reduced.
This is because the dispersibility of the default Ce, Mn, Sm, and Ti is decreased, and the synergistic effect of the components is decreased, resulting in a decrease in the catalytic activity and water-and sulfur-resistance of the catalyst. In addition, since Ce is strongerAcid site of B and oxidation of NO to NO2Thus, the three-way catalyst MnSmTiO with the default of Ce is enhancedxThe NO conversion rate and the water and sulfur resistance are obviously reduced, and the temperature window is also reduced to 200-350 ℃.
Comparative example 3
The comparative example provides a low-temperature SCR denitration catalyst CeSmTiOxThe catalyst is different from example 3 only in that the low-temperature SCR denitration catalyst of the comparative example does not contain Mn, and the molar ratio of the other three components Ce, Sm and Ti is the same as that of example 3; accordingly, in the preparation method of the low-temperature SCR denitration catalyst of the present comparative example, 50 wt.% Mn (NO) was not added3)2The aqueous solution, the remaining steps and the relevant parameters were the same as in example 3.
The prepared catalyst was tested for catalytic performance: 500ppm NH3500ppm NO, 5% O2, Ar is balance gas, and the space velocity is 80000h-1. It was found by detection (as shown in FIG. 1-2) that the NO conversion rate decreased to 73% at the reaction temperature of 140 ℃ and 400 ℃ and that N was2The selectivity was 86%. As can be seen, the Mn-deficient three-way catalyst CeSmTiOxThe catalytic activity of (a) is significantly reduced.
And (3) testing the water resistance and sulfur resistance of the prepared catalyst: SO is introduced into the simulated flue gas2And water vapor, SO2The concentration was 200ppm, the water vapor volume ratio was 5%, the other test conditions were unchanged, and the reaction temperature was 160 ℃. Under this test condition, the denitration efficiency of the catalyst dropped to 62% (see fig. 3). As can be seen, the Mn-deficient three-way catalyst CeSmTiOxThe water resistance and sulfur resistance of the product are obviously reduced.
This is because the dispersibility of the default Mn, Ce, Sm, and Ti is decreased, and the synergistic effect of the components is decreased, resulting in a decrease in the catalytic activity and water-and sulfur-resistance of the catalyst. In addition, Mn is absent as a three-way catalyst CeSmTiO because of its variable valence state and excellent redox ability, resulting in excellent low-temperature SCR activityxThe NO conversion rate and the water and sulfur resistance are obviously reduced, and the temperature window is also reduced to 200-350 ℃.
Comparative example 4
This comparative example provides a low temperature SCR stripperNitro catalyst MnCeSm (0.6) TiOxThe low-temperature SCR denitration catalyst of the comparative example is different from example 3 in the molar ratio of Mn, Ce, Sm and Ti of the four components in the low-temperature SCR denitration catalyst of the comparative example, namely Mn: Ce: Sm: Ti is 1:0.5:0.6: 4; correspondingly, in the preparation method of the low-temperature SCR denitration catalyst of the comparative example, 2.0g of Sm (NO) is added3)3·6H2O, the remaining steps and the relevant parameters are the same as in example 3.
The prepared catalyst was tested for catalytic performance: 500ppm NH3500ppm NO, 5% O2, Ar is balance gas, and the space velocity is 80000h-1. It was found by detection (as shown in FIG. 1-2) that the NO conversion rate decreased to 82% at the reaction temperature of 140 ℃ and 400 ℃ and that N was2The selectivity was 86%. As can be seen, MnCeSm (0.6) TiOxThe catalytic activity of (a) is significantly reduced.
And (3) testing the water resistance and sulfur resistance of the prepared catalyst: SO is introduced into the simulated flue gas2And water vapor, SO2The concentration was 200ppm, the water vapor volume ratio was 5%, the other test conditions were unchanged, and the reaction temperature was 160 ℃. Under this test condition, the denitration efficiency of the catalyst dropped to 66% (see fig. 3). As can be seen, MnCeSm (0.6) TiOxThe water resistance and sulfur resistance of the product are obviously reduced.
This is because excessive Sm causes clogging of catalyst channels and covers MnO2The activity of the catalyst and the water and sulfur resistance of the catalyst are reduced.
To further illustrate the properties of the catalysts, the present invention provides pore structure parameters of the low temperature SCR denitration catalysts of examples 1 to 4 and comparative examples 1 to 4, as shown in table 1.
Table 1 pore structure parameters of low-temperature SCR denitration catalysts prepared in examples 1 to 4 of the present invention and comparative examples 1 to 4
Figure BDA0002532712720000151
As can be seen from Table 1, a suitable amount of Sm improves the dispersion of the active oxide and increases the catalyst activitySpecific surface area of the agent, wherein MnCeSm (0.3) TiOxHas a large specific surface area and a small average pore diameter, which is equivalent to NH3The SCR reaction is advantageous, and the results of the catalyst performance tests likewise show MnCeSm (0.3) TiOxNO conversion, N2The selectivity and the water and sulfur resistance are both stronger.
In addition, as shown in fig. 4, the four catalysts prepared in example 3 and comparative examples 1 to 3 were all disordered agglomerated porous mixed metal oxide nanoparticles. Wherein, MnSm (0.3) TiOxThe number of bright spots (by FFT treatment of the displayed HRTEM image area) shown in the crystal area and SAED pattern shown in the HRTEM image of (1) was the largest, indicating that MnSm (0.3) TiOxIs an amorphous structure. And according to Table 1, MnSm (0.3) TiOxThe amorphous structure has higher specific surface area, so that the amorphous structure has good adsorption and diffusion capacity.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Furthermore, those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Claims (10)

1. The low-temperature SCR denitration catalyst is characterized by comprising manganese, cerium, samarium and titanium, wherein the molar ratio of the manganese to the cerium to the samarium to the titanium is Mn: Ce: Sm: Ti (0.1-1): 0.1-0.5): 4.
2. The low-temperature SCR denitration catalyst of claim 1, wherein the low-temperature SCR denitration catalyst is a porous mixed metal oxide nanoparticle.
3. A preparation method of a low-temperature SCR denitration catalyst is characterized by comprising the following steps:
(1) dissolving manganese salt, cerium salt, samarium salt and titanium salt in deionized water to obtain a mixed solution A;
(2) adding polyethylene glycol into the mixed solution A, heating and stirring to obtain a mixed solution B;
(3) adding an alkaline solution into the mixed solution B, adjusting the pH value, and stirring to obtain a mixed solution C;
(4) aging the mixed solution C in a closed container to obtain an intermediate product;
(5) and cooling the intermediate product, and carrying out solid-liquid separation, washing, drying and roasting to obtain the low-temperature SCR denitration catalyst.
4. The method of claim 3, wherein in the step (1), the molar ratio of the manganese salt, the cerium salt, the samarium salt and the titanium salt is Mn: Ce: Sm: Ti (0.1-1): (0.1-0.5): 4.
5. The preparation method of the low-temperature SCR denitration catalyst according to claim 3, wherein in the step (1), the manganese salt is manganese nitrate and/or manganese acetate; the cerium salt is cerium nitrate and/or cerium acetate; the samarium salt is samarium nitrate and/or samarium acetate; the titanium salt is titanium sulfate and/or tetrabutyl titanate.
6. The preparation method of the low-temperature SCR denitration catalyst according to claim 3, wherein the heating and stirring temperature in the step (2) is 25-40 ℃, and the heating time is 30-60 min.
7. The preparation method of the low-temperature SCR denitration catalyst according to claim 3, wherein in the step (3), the pH is adjusted to 10 to 12; the stirring time is 5-8 h.
8. The preparation method of the low-temperature SCR denitration catalyst as recited in claim 3, wherein in the step (4), the aging temperature is 100-120 ℃, and the aging time is 24-36 h.
9. The preparation method of the low-temperature SCR denitration catalyst as recited in claim 3, wherein in the step (5), the drying temperature is 100 ℃ and 130 ℃, and the drying time is 11-14 h.
10. The preparation method of the low-temperature SCR denitration catalyst as recited in claim 3, wherein in the step (5), the calcination temperature is 500-600 ℃, and the calcination time is 5-8 h.
CN202010522694.0A 2020-06-10 2020-06-10 Low-temperature SCR denitration catalyst and preparation method thereof Pending CN111569866A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010522694.0A CN111569866A (en) 2020-06-10 2020-06-10 Low-temperature SCR denitration catalyst and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010522694.0A CN111569866A (en) 2020-06-10 2020-06-10 Low-temperature SCR denitration catalyst and preparation method thereof

Publications (1)

Publication Number Publication Date
CN111569866A true CN111569866A (en) 2020-08-25

Family

ID=72123907

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010522694.0A Pending CN111569866A (en) 2020-06-10 2020-06-10 Low-temperature SCR denitration catalyst and preparation method thereof

Country Status (1)

Country Link
CN (1) CN111569866A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114289046A (en) * 2021-12-14 2022-04-08 上海电力大学 Denitration catalyst with Sm as active ingredient, and preparation and application thereof

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103381362A (en) * 2013-07-22 2013-11-06 哈尔滨工业大学 Low-temperature manganese-based denitration catalyst and preparing method thereof
CN106268787A (en) * 2016-08-11 2017-01-04 武汉理工大学 A kind of samarium doping MnOxlow-temperature SCR catalyst and its preparation method and application
CN106902813A (en) * 2017-03-16 2017-06-30 山东师范大学 A kind of samarium doped, the manganese based denitration catalyst of zirconium and preparation method
CN107469811A (en) * 2017-08-16 2017-12-15 浙江浙能富兴燃料有限公司 A kind of wide temperature window denitrating catalyst and its preparation method and application
CN109772471A (en) * 2019-01-31 2019-05-21 北京科技大学 One kind low-temperature denitration catalyst containing samarium and preparation method thereof
CN110841653A (en) * 2019-08-28 2020-02-28 南京晓庄学院 Preparation method of low-temperature denitration catalyst

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103381362A (en) * 2013-07-22 2013-11-06 哈尔滨工业大学 Low-temperature manganese-based denitration catalyst and preparing method thereof
CN106268787A (en) * 2016-08-11 2017-01-04 武汉理工大学 A kind of samarium doping MnOxlow-temperature SCR catalyst and its preparation method and application
CN106902813A (en) * 2017-03-16 2017-06-30 山东师范大学 A kind of samarium doped, the manganese based denitration catalyst of zirconium and preparation method
CN107469811A (en) * 2017-08-16 2017-12-15 浙江浙能富兴燃料有限公司 A kind of wide temperature window denitrating catalyst and its preparation method and application
CN109772471A (en) * 2019-01-31 2019-05-21 北京科技大学 One kind low-temperature denitration catalyst containing samarium and preparation method thereof
CN110841653A (en) * 2019-08-28 2020-02-28 南京晓庄学院 Preparation method of low-temperature denitration catalyst

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
王美鑫等: "Mn-Ce-Ti低温NH3-SCR脱硝催化剂的改性及性能研究", 《第十届全国催化剂制备科学与技术研讨会（成都）论文集》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114289046A (en) * 2021-12-14 2022-04-08 上海电力大学 Denitration catalyst with Sm as active ingredient, and preparation and application thereof
CN114289046B (en) * 2021-12-14 2024-04-26 上海电力大学 Denitration catalyst taking Sm as active ingredient and preparation and application thereof

Similar Documents

Publication Publication Date Title
CN111229212B (en) CO-SCR denitration catalyst, preparation method and application
CN105214679B (en) A kind of water resistant sulfur resistive type denitrating flue gas powder catalyst, preparation method and its usage
CN108722477B (en) Anti-alkalosis efficient denitration catalyst and preparation method and application thereof
CN111905719B (en) Manganese-based catalyst and preparation method thereof
WO2017181570A1 (en) Alkali (alkaline earth) metal-resistant, sulfur-resistant, and water-resistant denitrification catalyst, and manufacturing method and application thereof
CN111185182B (en) Perovskite catalyst and preparation method and application thereof
CN108393085B (en) Attapulgite-loaded cerium-doped MnTiOX ternary-component low-temperature denitration catalyst and preparation method thereof
CN112742413B (en) Low-temperature SCR denitration catalyst and preparation method and application thereof
CN108097238B (en) Preparation method of Mn-Ce-Ti-O composite metal oxide catalyst
CN111569865A (en) Bio-based low-temperature denitration catalyst and preparation method thereof
CN110605114A (en) Application of mullite oxide supported catalyst in low-temperature selective catalytic reduction denitration
CN108479762A (en) A kind of manganese oxide catalyst and its preparation method and application
CN112337460A (en) Method for preparing Mn-based spinel low-temperature denitration catalyst by using complex acid solution
CN111569866A (en) Low-temperature SCR denitration catalyst and preparation method thereof
CN113398920B (en) Ultra-long cerium dioxide nanorod-loaded manganese oxide low-temperature denitration catalyst and preparation method thereof
CN110773224A (en) Preparation method of alkali metal-resistant denitration catalyst
CN107185555B (en) Preparation method of copper-doped cerium sulfide-based nanocrystalline denitration catalyst
CN112452326A (en) Preparation method of copper black titanium catalyst and application of copper black titanium catalyst in selective catalytic oxidation denitration
CN108126707A (en) A kind of low temperature, SCR denitration, the preparation method and application that nontoxic, composite oxides are carrier
CN112023908A (en) Nitrogen oxide removing catalyst and preparation method thereof
CN107469811A (en) A kind of wide temperature window denitrating catalyst and its preparation method and application
CN110721676A (en) Low-temperature SCR denitration catalyst and preparation method and application thereof
CN114471533B (en) Dual-functional nano rod-shaped manganese oxide catalyst and preparation method and application thereof
CN113522316B (en) Gas phase cerium-titanium sulfide supported tin oxide catalyst and preparation method and application thereof
CN108686647B (en) Low-temperature sulfur-resistant Mn-based SCR catalyst and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20200825