CN119926398A - A CO oxidation catalyst and its preparation method and application - Google Patents
A CO oxidation catalyst and its preparation method and application Download PDFInfo
- Publication number
- CN119926398A CN119926398A CN202411944278.4A CN202411944278A CN119926398A CN 119926398 A CN119926398 A CN 119926398A CN 202411944278 A CN202411944278 A CN 202411944278A CN 119926398 A CN119926398 A CN 119926398A
- Authority
- CN
- China
- Prior art keywords
- tio
- species
- catalyst
- powder
- oxidation catalyst
- 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
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Landscapes
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
The invention relates to the technical field of catalysts, and discloses a CO oxidation catalyst, a preparation method and application thereof. The CO oxidation catalyst comprises a composite carrier, nb 2O5, K species and Pt species which are loaded on the composite carrier, wherein the composite carrier comprises TiO 2 and La 2O3, and Pt-O-K bonds are formed between the K species and the Pt species. The CO oxidation catalyst has better sulfur resistance, better catalytic stability in the long-time use process and higher catalytic activity.
Description
Technical Field
The invention relates to the technical field of catalysts, in particular to a CO oxidation catalyst and a preparation method and application thereof.
Background
The catalytic oxidation technology is considered as an effective method for removing CO in industrial flue gas because of the characteristics of high efficiency, less secondary pollution and the like. Pt-based catalysts are currently commonly used as CO oxidation catalysts, but impurities in the flue gas, such as SO 2 and H 2 O, can irreversibly deactivate Pt-based catalysts during long-term operation under practical conditions. Wherein SO 2 can generate sulfate on the surface of the catalyst, and the chemical property of the catalyst is changed. Furthermore, the presence of H 2 O can exacerbate the poisoning of SO 2 on the catalyst surface, and form sticky H 2SO4 with SO 2 to cover the catalyst surface. These factors lead to a drastic decrease in the performance of the catalyst. Therefore, developing a high activity and high stability CO catalyst for industrial flue gas has become a challenge.
In order to prolong the service life of the catalyst as far as possible and reduce the cost of the catalyst, scientific researchers dope acidic oxides (such as WO 3) on the surface of the Pt-based catalyst according to the acid attribute of SO 2, and attract the outermost electrons of Pt by using the acidic oxides, SO that the electron pairing process of SO 2 and the surface of Pt is inhibited, and the aim of inhibiting the adsorption of SO 2 on the surface of the catalyst is fulfilled. However, in the doping process, the carrier is often doped with an acidic oxide, and then the active component Pt is loaded, which results in a decrease in catalytic activity of the catalyst, because the carrier commonly used for CO catalysis is an active carrier (such as TiO 2、ZrO2、CeO2), in which lattice oxygen provides O required for the CO catalysis, in addition, metal-carrier interaction (SMSI effect) between the active carrier and the active component plays an important role in controlling valence state and electron transfer of the active component, and after doping the acidic oxide, interaction between the active component and the carrier in the catalyst is interrupted, resulting in a decrease in the rate of CO oxidation reaction performed on the active component. Thus, conventional acidic oxide doping methods increase catalytic stability at the expense of catalytic activity.
Disclosure of Invention
In order to solve the technical problems, namely that doping acidic oxide can improve the stability of a Pt-based CO oxidation catalyst but can cause the reduction of catalytic activity, the invention provides a CO oxidation catalyst and a preparation method and application thereof. The CO oxidation catalyst has better sulfur (SO 2) resistance, better catalytic stability in the long-time use process and higher catalytic activity.
The specific technical scheme of the invention is as follows:
In a first aspect, the invention provides a CO oxidation catalyst, which comprises a composite carrier, and Nb 2O5, a K species and a Pt species supported on the composite carrier, wherein the composite carrier comprises TiO 2 and La 2O3, and Pt-O-K bonds are formed between the K species and the Pt species.
According to the invention, nb 2O5 is loaded in the catalyst, SO that electrons on the outermost layer of Pt can be attracted, and the electron pairing process between SO 2 and the surface of Pt is inhibited, SO that the sulfur resistance of the catalyst is improved, and the catalyst has better catalytic stability when being used for oxidizing CO in flue gas containing SO 2.
The introduction of Nb 2O5 can hinder the interaction between Pt and the active support TiO 2, resulting in a decrease in catalytic activity. Therefore, K species are introduced, and after the K species are doped into the catalyst, pt-O-K bonds can be formed between the K species and Pt species, so that a Pt-carrier bonding mode Pt-O-Ti is replaced. A strong metal-promoter interaction can occur between Pt and K species, K acting as an electron promoter modifies the electron state of nearby Pt sites, and electronegative O attracts electrons on Pt during formation of Pt-O-K, where electron-deficient Pt is in ionic form on the catalyst surface. In CO catalysis, the acquisition of active oxygen (O 2, hydroxyl) by the catalyst is a very critical step in the reaction. The promotion of the catalyst adsorption O 2 by the K species is attributed to the independent s electrons of the K outermost layer, which act as electron donors, promoting the adsorption of the electron acceptor gas (CO, O 2) on the catalyst surface. In addition, to maintain local charge balance, negatively charged hydroxyl groups (OH-or OH-x) are adsorbed on the surface of positively charged groups formed by Pt and K. Therefore, the doping of K species can effectively stabilize the surrounding hydroxyl groups of Pt, provide oxygen required by low-temperature oxidation for the catalyst, reduce the dependence of the catalyst on an active carrier TiO 2, and further solve the problem of reduced catalytic activity caused by Nb 2O5 doping.
And compared with Na element, the K element adopted in the invention has larger ionic radius, can be more effectively dispersed in the catalyst, and improves the efficiency of the catalytic reaction by changing the electron density, SO that the catalyst can show better stability and activity at high temperature or high SO 2 concentration. Also, the K species can form a stronger interaction between Pt and TiO 2, especially under high temperature conditions, helping to reduce Pt aggregation and thus maintain its active site dispersibility, which may be more pronounced in long-term reactions of the catalyst.
Compared with other acidic oxides, the invention adopts Nb 2O5 to improve the sulfur resistance of the catalyst, and has the advantages that Nb 2O5 can form a stronger coordination structure with K species, further polarize the hydroxyl groups on the surface of the oxide, thereby enhancing the activation capability of oxygen species. Meanwhile, nb 2O5 can effectively stabilize Pt-O-K bonds at low temperature, so that the low-temperature activity of the catalyst is improved.
In addition, la 2O3 is introduced into the carrier to form a composite carrier, so that the acidic environment can be further improved, the electron coupling effect of Pt-O-K is enhanced, and better catalytic activity and catalytic stability are further provided for the CO oxidation catalyst.
Preferably, the mass ratio of the TiO 2 to the La 2O3 is 8-10:1.
Preferably, the K species is K oxide and the Pt species is Pt oxide.
In a second aspect, the present invention provides a method for preparing the CO oxidation catalyst, comprising the steps of:
S1, mixing a K + solution with a composite carrier, drying and calcining;
s2, mixing the product of the step S1 with a Nb 2O5 precursor solution, drying and calcining;
and S3, mixing the product obtained in the step S3 with the Pt 3+ solution, drying and calcining.
In the preparation process, the K species are loaded firstly and then Nb 2O5 is loaded, so that the pre-loaded K can form more uniform alkaline active sites on the surface of the carrier, and the sites can form stronger coordination structures in the subsequent dispersion process of Nb 2O5, thereby improving the acidity and catalytic activity. In addition, alkali metal pretreatment may alter the hydroxyl distribution of the support surface, optimizing other redox reaction pathways that may be involved. By the mode, the prepared catalyst has higher catalytic activity and can still maintain higher activity after long-time use.
Preferably, in step S1, the mass ratio of the composite carrier to K + is 10:0.07-0.10.
Preferably, in step S2, the mass ratio of the product of step S1 to Nb element in the Nb 2O5 precursor solution is 10:0.1-0.3.
Preferably, in the step S3, the mass ratio of the product of the step S3 to Pt 3+ is 1:0.03-0.08.
Preferably, in step S1, the K + solution is a K 2CO3 solution, in step S2, the Nb 2O5 precursor is Nb (NO 3)5), and in step S3, the Pt 3+ solution is Pt (NO 3)3 solution).
Preferably, in the steps S1 to S3, the calcination is aerobic calcination, the temperature is 500-550 ℃, and the time is 2-3 hours.
In a third aspect, the invention provides the use of the CO oxidation catalyst in the catalysis of CO oxidation reactions.
Compared with the prior art, the invention has the following advantages:
(1) According to the invention, nb 2O5 is loaded in the catalyst, SO 2 resistance of the catalyst can be improved, nb 2O5 can form a stronger coordination structure with K, and Pt-O-K bonds can be more effectively stabilized at low temperature, SO that catalytic activity and catalytic stability can be improved to a greater extent.
(2) The invention solves the problem of reduced catalytic activity caused by doping of the acidic oxide Nb 2O5 by loading K species in the catalyst, and can utilize the larger ionic radius of K and stronger interaction formed between Pt and TiO 2 to endow the catalyst with better catalytic activity and catalytic stability.
(3) According to the invention, la 2O3 is introduced into the catalyst carrier, so that the electron coupling effect of Pt-O-K can be enhanced, and the catalyst has better catalytic activity and catalytic stability.
(4) The method adopts the sequence of loading K species and then loading Nb 2O5 in the process of preparing the catalyst, so that the catalytic activity and the catalytic stability of the catalyst can be further improved.
Drawings
Fig. 1 shows the results of the detection of the catalytic activity of the CO oxidation catalysts of example 1 and comparative examples 1 to 5.
Fig. 2 shows the results of the catalytic stability test of the CO oxidation catalysts of example 1 and comparative examples 1 to 5.
Fig. 3 shows the results of the detection of the catalytic activity of the CO oxidation catalysts of examples 1 to 3.
Fig. 4 shows the results of the catalytic stability test of the CO oxidation catalysts of examples 1 to 3.
Detailed Description
The invention is further described below with reference to examples.
General examples
First, the invention relates to a CO oxidation catalyst, which comprises a composite carrier, nb 2O5, a K species and a Pt species, wherein the Nb 2O5, the K species and the Pt species are supported on the composite carrier, the composite carrier comprises TiO 2 and La 2O3, and a Pt-O-K bond is formed between the K species and the Pt species. In the CO oxidation catalyst, under the coordination effect of TiO 2、La2O3、Nb2O5, K species and Pt species, the catalyst has higher catalytic activity and better sulfur (SO 2) resistance, and can still maintain higher catalytic activity after long-term use in flue gas containing SO 2.
In some embodiments, the mass ratio of the TiO 2 to the La 2O3 is 8-10:1.
In some embodiments, the K species is a K oxide and the Pt species is a Pt oxide.
Second, the invention relates to a preparation method of the CO oxidation catalyst, comprising the following steps:
S1, mixing a K + solution with a composite carrier, drying and calcining;
s2, mixing the product of the step S1 with a Nb 2O5 precursor solution, drying and calcining;
and S3, mixing the product obtained in the step S3 with the Pt 3+ solution, drying and calcining.
In the preparation method, the catalytic activity and the catalytic stability of the catalyst can be further improved by adopting the sequence of loading K species and then loading Nb 2O5.
In some embodiments, in step S1, the mass ratio of the composite carrier to K + is 10:0.07-0.10.
In some embodiments, in step S2, the mass ratio of the product of step S1 to Nb element in the Nb 2O5 precursor solution is 10:0.1-0.3.
In some embodiments, in step S3, the mass ratio of the product of step S3 to Pt 3+ is 1:0.03-0.08.
In some embodiments, in step S1, the K + solution is a K 2CO3 solution, in step S2, the Nb 2O5 precursor is Nb (NO 3)5), and in step S3, the Pt 3+ solution is Pt (NO 3)3 solution).
In some embodiments, in steps S1-S3, the calcination is aerobic calcination, the temperature is 500-550 ℃, and the time is 2-3 hours.
Thirdly, the invention relates to the use of the above-mentioned CO oxidation catalyst for catalyzing CO oxidation reactions.
In some embodiments, the temperature of the CO oxidation reaction is no less than 95 ℃.
The invention is illustrated by the following specific examples. It is to be understood that these embodiments are merely for illustrating the present invention and are not to be construed as limiting the scope of the present invention, and that variations and advantages which can be conceived by those skilled in the art are included therein without departing from the spirit and scope of the inventive concept, and the appended claims and any equivalents thereof are intended to be protected by the present invention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The raw materials and equipment used in the invention are conventional in the art, and can be obtained from conventional commercial sources unless otherwise specified, and the methods used in the invention are conventional in the art.
Example 1 preparation of catalyst Pt-Nb 2O5-K/TiO2-La2O3
The CO oxidation catalyst (Pt-Nb 2O5-K/TiO2-La2O3) was prepared by the following steps:
S1 load K species
Under the condition of 70 ℃ water bath, 0.14g K 2CO3 of deionized water is added into a beaker containing 100mL of deionized water, after the deionized water is fully dissolved, 10g of TiO 2-La2O3 composite carrier (composed of TiO 2 and La 2O3 with the mass ratio of 9:1) is added, and the mixture is stirred to be sticky. After the excessive water is removed by a 100 ℃ oven for one night, grinding the water into powder, putting the powder into a muffle furnace, and calcining the powder for 2 hours at 500 ℃ in an air atmosphere to obtain K/TiO 2-La2O3.
S2 load Nb 2O5
0.606G of Nb (NO 3)5, after full dissolution, 10g of K/TiO 2-La2O3 prepared in the step S1 is added into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, stirred to be sticky, placed in a 100 ℃ oven for one night to remove excessive moisture, ground into powder, placed into a muffle furnace, and calcined for 2h at 500 ℃ in an air atmosphere to obtain Nb 2O5-K/TiO2-La2O3.
S3 Supported Pt species
13.4ML of 5g/L Pt (NO 3)3 solution, stirring uniformly) is added into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, then 9.95g of Nb 2O5-K/TiO2-La2O3 prepared in the step S2 is added, stirring is carried out until the mixture is thick, the mixture is placed in a100 ℃ oven for one night to remove excessive water, then the mixture is ground into powder, the powder is placed in a muffle furnace, and the mixture is calcined for 2 hours at 500 ℃ in an air atmosphere, so as to obtain a CO oxidation catalyst which is recorded as Pt-Nb 2O5-K/TiO2-La2O3.
Example 2 preparation of catalyst Pt-Nb 2O5-K/TiO2-La2O3
The CO oxidation catalyst (Pt-Nb 2O5-K/TiO2-La2O3) was prepared by the following steps:
S1 load K species
Under the condition of 70 ℃ water bath, 0.13g K 2CO3 of deionized water is added into a beaker containing 100mL of deionized water, after the deionized water is fully dissolved, 10g of TiO 2-La2O3 composite carrier (composed of TiO 2 and La 2O3 in a mass ratio of 8:1) is added, and the mixture is stirred to be sticky. After the excessive water is removed by a 100 ℃ oven for one night, grinding the water into powder, putting the powder into a muffle furnace, and calcining the powder for 2 hours at 550 ℃ in an air atmosphere to obtain K/TiO 2-La2O3.
S2 load Nb 2O5
0.434G of Nb (NO 3)5, after full dissolution, 10g of K/TiO 2-La2O3 prepared in the step S1 is added into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, stirred to be sticky, placed in a 100 ℃ oven for one night to remove excessive moisture, ground into powder, placed into a muffle furnace, and calcined for 2h at 550 ℃ in an air atmosphere to obtain Nb 2O5-K/TiO2-La2O3.
S3 Supported Pt species
15.5ML of 10g/L Pt (NO 3)3 solution, stirring uniformly) is added into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, then 9.95g of Nb 2O5-K/TiO2-La2O3 prepared in the step S2 is added, stirring is carried out until the mixture is thick, the mixture is placed in a 100 ℃ oven for one night to remove excessive water, then the mixture is ground into powder, the powder is placed in a muffle furnace, and the mixture is calcined for 2h at 550 ℃ in an air atmosphere, so as to obtain a CO oxidation catalyst which is recorded as Pt-Nb 2O5-K/TiO2-La2O3.
Example 3 preparation of catalyst Pt-Nb 2O5-K/TiO2-La2O3
The CO oxidation catalyst (Pt-Nb 2O5-K/TiO2-La2O3) was prepared by the following steps:
S1 load K species
Under the condition of 70 ℃ water bath, 0.17g K 2CO3 of deionized water is added into a beaker containing 100mL of deionized water, after the deionized water is fully dissolved, 10g of TiO 2-La2O3 composite carrier (composed of TiO 2 and La 2O3 in a mass ratio of 10:1) is added, and the mixture is stirred to be sticky. After the excessive water is removed by a 100 ℃ oven for one night, grinding the water into powder, putting the powder into a muffle furnace, and calcining the powder for 3 hours at 500 ℃ in an air atmosphere to obtain K/TiO 2-La2O3.
S2 load Nb 2O5
1.301G of Nb (NO 3)5, after complete dissolution, 10g of K/TiO 2-La2O3 prepared in step S1 is added to a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, stirred to be viscous, placed in a 100 ℃ oven for one night to remove excessive moisture, ground into powder, placed in a muffle furnace, and calcined for 3h at 500 ℃ in an air atmosphere to obtain Nb 2O5-K/TiO2-La2O3.
S3 Supported Pt species
Under the condition of 70 ℃ water bath, 11.7mL of 5g/L Pt (NO 3)3 solution, stirring uniformly) is added into a beaker containing 100mL of deionized water, then 9.95g of Nb 2O5-K/TiO2-La2O3 prepared in the step S2 is added, stirring is carried out until the mixture is thick, the mixture is placed in a100 ℃ oven for one night to remove excessive water, then the mixture is ground into powder, the powder is placed into a muffle furnace, and the muffle furnace is calcined at 500 ℃ for 3 hours in an air atmosphere, so that a CO oxidation catalyst which is recorded as Pt-Nb 2O5-K/TiO2-La2O3 is obtained.
Comparative example 1 preparation of catalyst Pt-WO 3-K/TiO2-La2O3
The difference between this comparative example and example 1 is only that the kind of the acidic oxide was changed in the catalyst of this comparative example, and that Nb 2O5 was changed to WO 3. The rest of the procedure is the same as in example 1.
Specifically, the CO oxidation catalyst (Pt-WO 3-K/TiO2-La2O3) of this comparative example was prepared by the following steps S1: supported K species
Under the condition of 70 ℃ water bath, 0.14g K 2CO3 of deionized water is added into a beaker containing 100mL of deionized water, after the deionized water is fully dissolved, 10g of TiO 2-La2O3 composite carrier (composed of TiO 2 and La 2O3 with the mass ratio of 9:1) is added, and the mixture is stirred to be sticky. After the excessive water is removed by a 100 ℃ oven for one night, grinding the water into powder, putting the powder into a muffle furnace, and calcining the powder for 2 hours at 500 ℃ in an air atmosphere to obtain K/TiO 2-La2O3.
S2 load WO 3
Under the condition of 70 ℃ water bath, 0.24g (NH 4)6W7O24·6H2 O is added into a beaker containing 100mL of deionized water, after full dissolution, 10g of K/TiO 2-La2O3 prepared in the step S1 is added, the mixture is stirred to be sticky, a 100 ℃ oven is placed for one night to remove excessive moisture, the mixture is ground into powder, and the powder is placed into a muffle furnace to be calcined for 2 hours at 500 ℃ in an air atmosphere, so that WO 3-K/TiO2-La2O3 is obtained.
S3, adding 13.4mL of 5g/L Pt (NO 3)3 solution, stirring uniformly, then adding 9.95g of WO 3-K/TiO2-La2O3 prepared in the step S2 into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, stirring to be sticky, standing in a 100 ℃ oven for one night to remove excessive water, grinding into powder, placing into a muffle furnace, calcining for 2 hours at 500 ℃ in the air atmosphere, and obtaining the CO oxidation catalyst, namely 'Pt-WO 3-K/TiO2-La2O3'.
Comparative example 2 preparation of catalyst Pt-K-Nb 2O5/TiO2-La2O3
The comparative example differs from example 1 only in that the comparative example changes the loading order of the K species and Nb 2O5, and Nb 2O5 is loaded first and then the K species. The rest of the procedure is the same as in example 1.
Specifically, the CO oxidation catalyst (Pt-K-Nb 2O5/TiO2-La2O3) of this comparative example was prepared by the following steps S1: supported Nb 2O5
0.606G of Nb (NO 3)5, after full dissolution, 10g of TiO 2-La2O3 composite carrier (composed of TiO 2 and La 2O3 in a mass ratio of 9:1) is added into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, stirred to be sticky, and after the excessive water is removed by standing in a 100 ℃ oven for one night, the mixture is ground into powder, and the powder is put into a muffle furnace for calcination for 2 hours at 500 ℃ in an air atmosphere, so that Nb 2O5/TiO2-La2O3 is obtained.
S2 loading of K species
Under the condition of 70 ℃ water bath, 0.14g K 2CO3 of Nb 2O5/TiO2-La2O3 prepared in the step S2 is added into a beaker containing 100mL of deionized water, and after the solution is fully dissolved, 10g of Nb 2O5/TiO2-La2O3 is added and stirred to be sticky. And (3) placing the mixture in a 100 ℃ oven for one night to remove excessive moisture, grinding the mixture into powder, placing the powder into a muffle furnace, and calcining the powder for 2 hours at 500 ℃ in an air atmosphere to obtain K-Nb 2O5/TiO2-La2O3.
S3 Supported Pt species
13.4ML of 5g/L Pt (NO 3)3 solution, stirring uniformly) is added into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, then 9.95g of K-Nb 2O5/TiO2-La2O3 prepared in the step S2 is added, stirring is carried out until the mixture is thick, the mixture is placed in a 100 ℃ oven for one night to remove excessive water, then the mixture is ground into powder, the powder is placed in a muffle furnace, and the mixture is calcined for 2 hours at 500 ℃ in an air atmosphere, so that a CO oxidation catalyst which is recorded as Pt-K-Nb 2O5/TiO2-La2O3 is obtained.
Comparative example 3 preparation of catalyst Pt- (Nb 2O5-K)/TiO2-La2O3)
The comparative example differs from example 1 only in that the comparative example changes the order of loading of the K species and Nb 2O5, and the K species and Nb 2O5 are loaded together on the support. The rest of the procedure is the same as in example 1.
Specifically, the CO oxidation catalyst (Pt- (Nb 2O5-K)/TiO2-La2O3) of this comparative example was prepared by the steps of S1: supporting K species and Nb 2O5
0.14G K 2CO3 and 0.606g Nb (NO 3)5, after sufficient dissolution) were added to a beaker containing 100mL of deionized water under 70 ℃ water bath conditions, 10g of TiO 2-La2O3 composite carrier (composed of TiO 2 and La 2O3 in a mass ratio of 9:1) was added, stirred to be viscous, and after standing in a 100 ℃ oven for one night to remove excessive moisture, the mixture was ground into powder, and the powder was placed in a muffle furnace and calcined at 500 ℃ for 2 hours under an air atmosphere to obtain (Nb 2O5-K)/TiO2-La2O3).
S2 Supported Pt species
13.4ML of 5g/L Pt (NO 3)3 solution, stirred uniformly) was added to a beaker containing 100mL of deionized water under a 70 ℃ water bath condition, then 9.95g of the solution prepared in step S1 was added (Nb 2O5-K)/TiO2-La2O3, stirred to be viscous, placed in a 100 ℃ oven for one night to remove excessive water, ground into powder, placed in a muffle furnace, and calcined at 500 ℃ for 2h under an air atmosphere to obtain a CO oxidation catalyst, which was designated as 'Pt- (Nb 2O5-K)/TiO2-La2O3').
Comparative example 4 preparation of catalyst Pt-Nb 2O5-K/TiO2
The comparative example differs from example 1 only in that the support used in this comparative example was TiO 2 and did not contain La 2O3. The rest of the procedure is the same as in example 1.
Specifically, the CO oxidation catalyst (Pt-Nb 2O5-K/TiO2) of this comparative example was prepared by the following steps:
S1 load K species
Under the condition of 70 ℃ water bath, 0.14g K 2CO3 g of TiO 2 carrier is added into a beaker containing 100mL of deionized water, and after the solution is fully dissolved, the mixture is added into the beaker, and the mixture is stirred to be sticky. After the excessive water is removed by a 100 ℃ oven for one night, grinding the water into powder, putting the powder into a muffle furnace, and calcining the powder for 2 hours at 500 ℃ in an air atmosphere to obtain K/TiO 2.
S2 load Nb 2O5
0.606G of Nb (NO 3)5, after full dissolution, 10g of K/TiO 2 prepared in the step S1 is added into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, stirred to be sticky, placed in a 100 ℃ oven for one night to remove excessive moisture, ground into powder, placed into a muffle furnace, and calcined for 2h at 500 ℃ in an air atmosphere to obtain Nb 2O5-K/TiO2.
S3 Supported Pt species
13.4ML of 5g/L Pt (NO 3)3 solution, stirring uniformly) is added into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, then 9.95g of Nb 2O5-K/TiO2 prepared in the step S2 is added, stirring is carried out until the mixture is thick, the mixture is placed in a100 ℃ oven for one night to remove excessive water, then the mixture is ground into powder, the powder is placed in a muffle furnace, and the mixture is calcined for 2 hours at 500 ℃ in an air atmosphere, so as to obtain a CO oxidation catalyst which is recorded as Pt-Nb 2O5-K/TiO2.
Comparative example 5 preparation of catalyst Pt-Nb 2O5-Na/TiO2-La2O3
The comparative example differs from example 1 only in that in the catalyst of the comparative example, the K species was replaced by Na species. The rest of the procedure is the same as in example 1.
Specifically, the CO oxidation catalyst (Pt-Nb 2O5-Na/TiO2-La2O3) of this comparative example was prepared by S1, adding 0.14g Na 2CO3 to a beaker containing 100mL deionized water at 70℃in a water bath, sufficiently dissolving, adding 10g of TiO 2-La2O3 composite carrier (composed of TiO 2 and La 2O3 in a mass ratio of 9:1), and stirring to be viscous. After the excessive water is removed by a 100 ℃ oven for one night, grinding the water into powder, putting the powder into a muffle furnace, and calcining the powder for 2 hours at 500 ℃ in an air atmosphere to obtain Na/TiO 2-La2O3.
S2 load Nb 2O5
0.606G of Nb (NO 3)5, after full dissolution, 10g of Na/TiO 2-La2O3 prepared in the step S1 is added into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, stirred to be sticky, placed in a 100 ℃ oven for one night to remove excessive moisture, ground into powder, placed into a muffle furnace, and calcined for 2h at 500 ℃ in an air atmosphere to obtain Nb 2O5-Na/TiO2-La2O3.
S3 Supported Pt species
13.4ML of 5g/L Pt (NO 3)3 solution, stirring uniformly) is added into a beaker containing 100mL of deionized water under the condition of 70 ℃ water bath, then 9.95g of Nb 2O5-Na/TiO2-La2O3 prepared in the step S2 is added, stirring is carried out until the mixture is thick, the mixture is placed in a100 ℃ oven for one night to remove excessive water, then the mixture is ground into powder, the powder is placed in a muffle furnace, and the mixture is calcined for 2 hours at 500 ℃ in an air atmosphere, so as to obtain a CO oxidation catalyst which is recorded as Pt-Nb 2O5-Na/TiO2-La2O3.
Test examples catalytic Activity and catalytic stability test
The CO oxidation catalysts prepared according to the methods of examples and comparative examples were used to catalyze the oxidation of CO in flue gas under the flue gas conditions (the contents of the following components are all by volume fraction) CO 8000ppm, O 2 16％,N2 as balance gas, and space velocity 30000h -1. The measured CO conversions at different temperatures are shown in fig. 1 and 3 (the term "Pt-Nb 2O5-K/TiO2-La2O3" in fig. 1 refers to the catalyst prepared according to the method of example 1).
The CO oxidation catalysts prepared according to the methods of examples and comparative examples were used to catalyze CO oxidation in flue gas under the conditions of CO 8000ppm and O 2 16％,SO2 50ppm,H2O 15％,N2 as balance gas at 170℃and a space velocity of 30000h -1. After a prolonged period of use, the measured CO conversions are shown in FIGS. 2 and 4 (the term "Pt-Nb 2O5-K/TiO2-La2O3" in FIG. 2 refers to the catalyst prepared according to the procedure of example 1).
From fig. 1 to 4, it can be seen that:
(1) The catalyst of example 1 (Pt-Nb 2O5-K/TiO2-La2O3) has higher catalytic activity and stability than the catalyst of comparative example 1 (Pt-WO 3-K/TiO2-La2O3). The reason is presumed that Nb 2O5 is capable of forming a stronger coordination structure with K species than WO 3, further polarizes the oxide surface hydroxyl groups, thereby enhancing the activation ability of oxygen species, and at the same time Nb 2O5 is also capable of more effectively stabilizing Pt-O-K bonds at low temperature, thereby improving the low temperature activity of the catalyst.
(2) The reason for this is presumed to be that the pre-supported K forms more uniform basic active sites on the support surface when the order of K species loading followed by Nb 2O5 is adopted, and these sites form stronger coordination structures during the subsequent dispersion of Nb 2O5, thereby enhancing acidity and catalytic activity, and that the alkali pretreatment may alter the hydroxyl distribution on the support surface to optimize other oxidation-reduction reaction pathways that may be involved, while the above-described effect cannot be produced when the order of K species loading and Nb 2O5 loading is changed, or both are carried together, as compared to the catalyst of comparative example 2 (Pt-K-Nb 2O5/TiO2-La2O3) and the catalyst of comparative example 3 (Pt- (Nb 2O5-K)/TiO2-La2O3).
(3) The catalyst of example 1 has higher catalytic activity and stability than the catalyst of comparative example 4 (Pt-Nb 2O5-K/TiO2). The reason is presumed that, compared with the method which adopts TiO 2 as the carrier alone, the method can further promote the acidic environment and strengthen the electron coupling effect of Pt-O-K by introducing La 2O3 into the carrier to form a composite carrier, thereby further endowing the CO oxidation catalyst with better catalytic activity and catalytic stability.
(4) The catalyst of example 1 has higher catalytic activity and stability than the catalyst of comparative example 5 (Pt-Nb 2O5-Na/TiO2-La2O3). The reason is presumed that the K element has a larger ionic radius than the Na element, can be more effectively dispersed in the catalyst, and improves the efficiency of the catalytic reaction by changing the electron density, which enables the catalyst to exhibit better stability and activity at high temperature or high SO 2 concentration, and the K species can form stronger interaction between Pt and TiO 2, particularly under high temperature conditions, helping to reduce aggregation of Pt, thereby maintaining the dispersibility of its active sites, which may be more remarkable in the long-term reaction of the catalyst.
The foregoing description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and any simple modification, variation and equivalent transformation of the above embodiment according to the technical substance of the present invention still fall within the scope of the technical solution of the present invention.
Claims (10)
1. A CO oxidation catalyst is characterized by comprising a composite carrier, nb 2O5, a K species and a Pt species, wherein the Nb 2O5, the K species and the Pt species are supported on the composite carrier, the composite carrier comprises TiO 2 and La 2O3, and a Pt-O-K bond is formed between the K species and the Pt species.
2. The CO oxidation catalyst according to claim 1, wherein the mass ratio of TiO 2 to La 2O3 is 8-10:1.
3. The CO oxidation catalyst of claim 1, wherein the K species is a K oxide and the Pt species is a Pt oxide.
4. A method for preparing the CO oxidation catalyst according to any one of claims 1 to 3, comprising the steps of:
S1, mixing a K + solution with a composite carrier, drying and calcining;
s2, mixing the product of the step S1 with a Nb 2O5 precursor solution, drying and calcining;
and S3, mixing the product obtained in the step S3 with the Pt 3+ solution, drying and calcining.
5. The preparation method of claim 4, wherein in the step S1, the mass ratio of the composite carrier to K + is 10:0.07-0.10.
6. The method according to claim 4, wherein in the step S2, the mass ratio of the product of the step S1 to Nb element in the Nb 2O5 precursor solution is 10:0.1-0.3.
7. The method according to claim 4, wherein in the step S3, the mass ratio of the product of the step S3 to Pt 3+ is 1:0.03-0.08.
8. The method according to any one of claims 4 to 7, wherein in step S1, the K + solution is a K 2CO3 solution, in step S2, the Nb 2O5 precursor is Nb (NO 3)5), and in step S3, the Pt 3+ solution is Pt (NO 3)3 solution).
9. The method according to claim 4, wherein in the steps S1 to S3, the calcination is aerobic calcination at 500 to 550 ℃ for 2 to 3 hours.
10. Use of a CO oxidation catalyst according to one of claims 1 to 3 for catalyzing CO oxidation reactions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411944278.4A CN119926398A (en) | 2024-12-27 | 2024-12-27 | A CO oxidation catalyst and its preparation method and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411944278.4A CN119926398A (en) | 2024-12-27 | 2024-12-27 | A CO oxidation catalyst and its preparation method and application |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN119926398A true CN119926398A (en) | 2025-05-06 |
Family
ID=95543982
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202411944278.4A Pending CN119926398A (en) | 2024-12-27 | 2024-12-27 | A CO oxidation catalyst and its preparation method and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN119926398A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3784675A (en) * | 1971-08-02 | 1974-01-08 | Gulf Research Development Co | Process for reducing the content of nitrogen oxides in the exhaust gases from internal combustion engines |
| JP2002102704A (en) * | 2000-10-02 | 2002-04-09 | Matsushita Electric Ind Co Ltd | Exhaust gas purifying catalyst and exhaust gas purifying material using the same |
| CN105727943A (en) * | 2016-01-27 | 2016-07-06 | 清华大学 | Method for synthesizing nano three-way catalyst |
| CN117599841A (en) * | 2015-07-30 | 2024-02-27 | 巴斯夫公司 | Diesel oxidation catalyst |
| CN118304885A (en) * | 2024-04-15 | 2024-07-09 | 浙江大学 | Heavy metal poisoning resistant CO platinum oxide/palladium-based catalyst, preparation method and application thereof |
-
2024
- 2024-12-27 CN CN202411944278.4A patent/CN119926398A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3784675A (en) * | 1971-08-02 | 1974-01-08 | Gulf Research Development Co | Process for reducing the content of nitrogen oxides in the exhaust gases from internal combustion engines |
| JP2002102704A (en) * | 2000-10-02 | 2002-04-09 | Matsushita Electric Ind Co Ltd | Exhaust gas purifying catalyst and exhaust gas purifying material using the same |
| CN117599841A (en) * | 2015-07-30 | 2024-02-27 | 巴斯夫公司 | Diesel oxidation catalyst |
| CN105727943A (en) * | 2016-01-27 | 2016-07-06 | 清华大学 | Method for synthesizing nano three-way catalyst |
| CN118304885A (en) * | 2024-04-15 | 2024-07-09 | 浙江大学 | Heavy metal poisoning resistant CO platinum oxide/palladium-based catalyst, preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103537279B (en) | A kind of low-temperature denitration catalyst adding auxiliary agent and preparation method thereof | |
| CN107456965B (en) | It is a kind of using cerium oxide as load type palladium catalyst of carrier and preparation method thereof | |
| CN110801829B (en) | Amorphous Ce x MnO 2 Material, preparation method and application thereof | |
| CN102000582B (en) | Preparation and application of sulfur-resistant La0.7Sr0.3Co1-xFexO3 perovskite catalyst | |
| CN109794272B (en) | A kind of supported phosphomolybdenum heteropolyacid low-temperature SCR catalyst and preparation method thereof | |
| CN104353455A (en) | Au-loaded different-crystalline-phase ZrO2 catalyst as well as preparation method and application thereof | |
| JP2014073485A (en) | Catalyst for decomposing nitrogen oxide and preparation method thereof | |
| CN113522272A (en) | A kind of denitration catalyst and preparation method thereof | |
| CN111686803A (en) | Environment-friendly VOCs low-temperature combustion catalyst and preparation method thereof | |
| CN108816218A (en) | Modified vanadium series catalyst of a kind of Mn oxide for exhaust gas from diesel vehicle denitration and its preparation method and application | |
| CN113019411B (en) | Boron nitride supported platinum-based catalyst for low-temperature selective catalytic oxidation of ammonia, preparation method and application thereof | |
| CN113663671A (en) | Ternary metal catalyst and preparation method and application thereof | |
| JP4432588B2 (en) | Catalyst and method for producing catalyst | |
| CN113083286B (en) | A kind of preparation method of ultra-high temperature denitrification catalyst | |
| CN119926398A (en) | A CO oxidation catalyst and its preparation method and application | |
| CN107185523A (en) | Preparation method of denitrating catalyst that a kind of holmium is modified and products thereof | |
| CN114849699A (en) | Biochar-based supported catalyst and preparation method and application thereof | |
| JP4483348B2 (en) | catalyst | |
| CN119500119A (en) | Metal promoter modified Pt supported CeO2 catalyst, preparation and application in CO oxidation | |
| US11697109B2 (en) | Catalyst particles for treating vehicle exhaust gas, preparation method therefor, and method for treating vehicle exhaust gas by using same | |
| CN117380238A (en) | A loaded wide-temperature, sulfur-resistant, water-resistant, CO-resistant SCR denitrification catalyst for the steel industry and its preparation method and application | |
| CN102188972B (en) | Fuel cell catalyst and preparation method thereof | |
| CN114247447B (en) | Low-temperature denitration catalyst taking modified carbon material as carrier and preparation method thereof | |
| CN116371429A (en) | Supported vanadate denitration catalyst and preparation method and application thereof | |
| JP4779461B2 (en) | Catalyst carrier, method for producing the same, and exhaust gas purification catalyst |
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 |