CN114100610A - Gold catalyst, preparation method and application thereof - Google Patents

Gold catalyst, preparation method and application thereof Download PDF

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CN114100610A
CN114100610A CN202111534004.4A CN202111534004A CN114100610A CN 114100610 A CN114100610 A CN 114100610A CN 202111534004 A CN202111534004 A CN 202111534004A CN 114100610 A CN114100610 A CN 114100610A
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gold
gold catalyst
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catalyst
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张长斌
秦晓晓
陈敏
陈学燕
张江浩
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Research Center for Eco Environmental Sciences of CAS
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
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    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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    • 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
    • B01D53/864—Removing carbon monoxide or hydrocarbons
    • 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
    • B01D53/8668—Removing organic compounds not provided for in B01D53/8603 - B01D53/8665
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    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/48—Silver or gold
    • B01J23/52—Gold
    • 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

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Abstract

The invention provides a gold catalyst and a preparation method and application thereof, wherein a deposition precipitation method is improved for preparing a supported gold catalyst by omitting heating, repeated washing and roasting, and the gold catalyst obtained by the invention has excellent formaldehyde oxide and carbon monoxide performances.

Description

Gold catalyst, preparation method and application thereof
Technical Field
The invention belongs to the technical field of catalyst preparation, and particularly relates to a gold catalyst, and a preparation method and application thereof.
Background
Formaldehyde and carbon monoxide are the mainThe indoor air pollutants of (2) have serious harm to human body. The main harm of formaldehyde is represented by stimulation to skin mucosa, and when the formaldehyde reaches a certain concentration indoors, people feel uncomfortable, and the concentration is more than 0.08mg/m3The formaldehyde concentration can cause redness, itching, discomfort or pain in the throat, hoarseness, sneezing, chest distress, asthma, dermatitis, etc. Carbon monoxide is a pollutant with strong toxicity to blood and nervous system, and carbon monoxide in air enters human blood through respiratory system and combines with hemoglobin in blood to form reversible combination. The combination of carbon monoxide and hemoglobin not only reduces the oxygen carrying capacity of blood cells, but also inhibits and delays the resolution and release of oxyhemoglobin, so that body tissues are necrotized due to oxygen deficiency, and serious patients can endanger human life.
The pollutants such as carbon monoxide and formaldehyde in indoor air have great negative effects on human health, and the catalytic oxidation of carbon monoxide and formaldehyde at low temperature and normal temperature by using a high-efficiency catalyst is a common air purification method.
Research shows that the gold catalyst has better low-temperature catalytic oxidation activity on carbon monoxide, formaldehyde and ethylene, and metal oxide is one of the carriers of the commonly used gold catalyst. Since gold has a high activity only in the form of nanoparticles having a certain particle size, generally speaking, there are high requirements on the catalyst preparation conditions and the catalyst preparation process. Commonly used methods for preparing metal oxide supported gold catalysts include coprecipitation and precipitation.
The coprecipitation method is that metal salt except gold and chloroauric acid are mixed and dissolved, a precipitator is added to form mixture sediment of non-gold hydroxide and gold hydroxide, and the catalyst is obtained after precipitation separation, drying and activation treatment. For example, CN105170146A discloses a preparation method of a supported gold catalyst using a layered composite hydroxide as a precursor, which specifically comprises the following steps: mixing chloroauric acid, magnesium metal salt and aluminum metal salt, synthesizing gold-containing layered composite hydroxide by a coprecipitation method, and then preparing gold nanoparticles in situ by liquid phase reduction by taking the composite hydroxide as a precursor to prepare a gold catalyst; the content of gold in the catalyst is 0.5-10.0 wt%, and the method has the advantages of mild reaction conditions, simple process, convenience in operation, good repeatability, easiness in realization of large-scale preparation and good application prospect. However, the coprecipitation method has a disadvantage in that gold is easily embedded in a carrier, resulting in low gold utilization.
The deposition precipitation method is to disperse the metal oxide carrier into the aqueous solution of chloroauric acid, add alkaline substances under the condition of fully stirring, control a certain temperature and pH value to deposit gold on the surface of the carrier, and then carry out separation, drying and activation treatment to obtain the catalyst. For example, CN103801326B discloses a supported nano-gold catalyst and a preparation method thereof, the preparation method of the supported nano-gold catalyst comprises contacting a carrier with an aqueous solution of tetrachloroauric acid in a rotary evaporator under the condition of deposition and precipitation to obtain a mixed solution containing a solid precipitate, then evaporating to remove water, and sequentially drying and calcining the obtained solid; the conditions for depositing the precipitate include: alkaline substances are adopted to adjust the pH value to 9-11, and the supported nano-gold catalyst prepared by the method has the advantages of high nano-gold loading rate, narrow particle size distribution, good dispersibility and small size.
CN101797514A discloses a preparation method of a high-temperature sintering resistant silicon-based nano gold catalyst, which specifically comprises the following steps: (1) adding a carrier into a chloroauric acid solution according to the gold loading amount of the catalyst, and adjusting the pH value of the chloroauric acid solution to 9-10; (2) stirring and aging the obtained mixed solution at normal temperature; (3) filtering the aged mixed solution, and repeatedly washing with deionized water until no chloride ion is detected in the filtrate; (4) filtering to obtain a filter cake, and drying; (5) the dried filter cake is pretreated and activated, and is respectively roasted in the reducing atmosphere of hydrogen and oxygen to obtain the silicon-based nano gold catalyst; the method takes silicon dioxide materials which are easy to realize industrialization as a carrier, takes chloroauric acid which is cheap and easy to obtain as a gold source, and prepares the silicon-based nano gold catalyst by a simple and easy deposition precipitation method, and the preparation method is simple and easy to implement, and the obtained silicon-based nano gold catalyst has excellent high-temperature sintering resistance.
However, the deposition-precipitation method has the disadvantages that conditions are not easy to control, reproducibility is often poor, a considerable portion of gold nucleates in a solution instead of depositing on the surface of a carrier, the deposition-precipitation method generally needs to bake a sample under a certain atmosphere and temperature or to perform reduction treatment to activate a catalyst, the treatment process is complicated, and the deposition-precipitation method has the problems of raw material waste, waste water generation, waste gas generation due to high-temperature baking and other secondary pollution.
Currently, a commonly used catalyst capable of efficiently removing formaldehyde and CO at room temperature is a platinum catalyst, for example, CN112371121A discloses a catalyst for removing formaldehyde and carbon monoxide at room temperature and a preparation method thereof, wherein the catalyst takes platinum-based noble metal as an active component, takes a manganesite-type octahedral molecular sieve as a carrier, and loads the platinum-based noble metal active component on the manganesite-type octahedral molecular sieve carrier; however, the catalyst has high cost, and the preparation method needs high-temperature roasting and reduction pretreatment, so that the process is complicated and secondary pollution such as waste gas exists.
The gold catalyst has high-efficiency performance of purifying formaldehyde and carbon monoxide at room temperature, so a novel preparation method of the gold catalyst needs to be developed urgently, the prepared gold catalyst has excellent performance of oxidizing formaldehyde and carbon monoxide, and the gold catalyst has the advantages of simple method, mild reaction conditions and strong repeatability.
Disclosure of Invention
The invention aims to provide a gold catalyst and a preparation method and application thereof, the gold catalyst is used for preparing a supported gold catalyst by improving a deposition precipitation method, and the gold catalyst has excellent formaldehyde oxide and carbon monoxide performances.
In order to achieve the purpose, the invention adopts the following technical scheme:
one of the objects of the present invention is to provide a method for preparing a gold catalyst, comprising the steps of:
(1) adjusting the pH value of the gold source solution to be alkaline to obtain an alkaline gold solution;
(2) and (2) mixing the carrier with the alkaline gold solution in the step (1) and then carrying out standing reaction to obtain a supernatant and a gold catalyst.
The preparation method is simple, has strong repeatability, mild reaction conditions, does not need heating reaction and high-temperature roasting, does not need repeated washing, has low preparation cost, and reduces the generation of waste gas and waste water.
It is worth to be noted that the supernatant obtained in the step (2) is recycled to the step (1) to be used as a gold source solution for pH adjustment, and the prepared gold catalyst has excellent activities of catalyzing and oxidizing formaldehyde and carbon monoxide.
As a preferable technical scheme of the invention, the gold source solution in the step (1) is a chloroauric acid aqueous solution.
As a preferred embodiment of the present invention, the final pH of the pH adjustment in step (1) is 9 to 11, and may be, for example, 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11, etc., but is not limited to the values listed above, and other values not listed above within the above-mentioned range of values are also applicable.
As a preferred technical scheme of the invention, the carrier in the step (2) comprises TiO2，CeO2Or Al2O3Any one or a combination of at least two of which typically, but not by way of limitation, comprise TiO2And CeO2Combinations of (A) and (B), TiO2And Al2O3Combination of (A) CeO2And Al2O3Combinations of (a) and (b).
Preferably, the mass ratio of the carrier in the step (2) to the gold source in the gold source solution in the step (1) is 1 (0.0002-0.1), and may be, for example, 1:0.0002, 1:0.001, 1:0.005, 1:0.01, 1:0.02, 1:0.03, 1:0.04, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, etc., but is not limited to the enumerated values, and other non-enumerated values within the above numerical range are also applicable.
In a preferred embodiment of the present invention, the final pH of the second pH adjustment in step (2) is 8 to 10, and may be, for example, 8, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10, etc., but not limited to the values listed above, and other values not listed above within the above-mentioned range of values are also applicable.
As a preferred embodiment of the present invention, the temperature of the standing reaction in the step (2) is 20 to 30 ℃ and may be, for example, 20 ℃, 21 ℃, 22 ℃, 23 ℃, 24 ℃, 25 ℃, 26 ℃, 27 ℃, 28 ℃, 29 ℃, 30 ℃ or the like, but it is not limited to the above-mentioned values, and other values not listed in the above-mentioned range of values are also applicable.
Preferably, the standing reaction in step (2) is carried out for 7 to 31 days, such as 7 days, 10 days, 12 days, 14 days, 16 days, 18 days, 20 days, 22 days, 24 days, 26 days, 28 days, 30 days, 31 days, etc., but it is not limited to the recited values, and other values not recited in the above-mentioned range of values are also applicable.
The standing reaction time is 7-31 days, and if the standing reaction time is less than 7 days, the performance of the catalyst is reduced, because the time is too short, the interaction between the gold and the carrier is weak, the gold cannot be fully precipitated on the surface of the carrier, and the dispersity of the gold is poor; if the time exceeds 31 days, not only the preparation time of the catalyst is prolonged, but also the catalyst is changed under the action of air, such as the valence state and the particle size of gold are changed, and the performance of the catalyst is also reduced.
As a preferred technical solution of the present invention, the preparation method further comprises: and (3) drying the gold catalyst obtained in the step (2).
Preferably, the temperature of the drying is 40-60 ℃, for example, 40 ℃, 41 ℃, 42 ℃, 3 ℃, 44 ℃, 45 ℃, 46 ℃, 47 ℃, 48 ℃, 49 ℃, 50 ℃, 51 ℃, 52 ℃, 53 ℃, 54 ℃, 55 ℃, 56 ℃, 57 ℃, 58 ℃, 59 ℃, 60 ℃ and the like, but is not limited to the recited values, and other values not recited in the above numerical range are also applicable.
Preferably, the drying time is 2-16h, such as 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, etc., but not limited to the recited values, and other values not recited in the above numerical range are also applicable.
As a preferable technical scheme of the invention, the supernatant obtained in the step (2) is recycled to the step (1) to be used as the gold source solution.
As a preferred technical scheme of the invention, the preparation method comprises the following steps:
(1) adjusting the pH of the chloroauric acid solution to the end point pH of 9-11 to obtain an alkaline gold solution;
(2) mixing a carrier with the alkaline gold solution obtained in the step (1), and standing and reacting for 7-31 days at the pH of 8-10 and the temperature of 20-30 ℃ to obtain a supernatant and a gold catalyst; drying the obtained gold catalyst for 2-16h at 40-60 ℃; recycling the obtained supernatant to the step (1) as a chloroauric acid solution;
wherein the support comprises TiO2，CeO2Or Al2O3Any one or a combination of at least two of; the mass ratio of the carrier to the chloroauric acid in the chloroauric acid solution in the step (1) is 1 (0.0002-0.1).
A second object of the present invention is to provide a gold catalyst obtained by the method of the first object, wherein the gold element is contained in an amount of 0.01 to 5 wt%, such as 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.2 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, 1.8 wt%, 2 wt%, 2.3 wt%, 2.5 wt%, 2.8 wt%, 3 wt%, 3.2 wt%, 3.5 wt%, 3.7 wt%, 4 wt%, 4.2 wt%, 4.5 wt%, 4.8 wt%, 5 wt%, etc., but not limited to the recited values, and other values not recited in the above range are also applicable.
The third object of the present invention is to provide the use of the gold catalyst of the second object for removing formaldehyde and/or carbon monoxide.
The recitation of numerical ranges herein includes not only the above-recited numerical values, but also any numerical values between non-recited numerical ranges, and is not intended to be exhaustive or to limit the invention to the precise numerical values encompassed within the range for brevity and clarity.
Compared with the prior art, the invention has the following beneficial effects:
(1) the gold catalyst has excellent formaldehyde and carbon monoxide oxidation performance, and can convert pollutants into nontoxic and harmless carbon dioxide;
(2) the preparation method of the gold catalyst is simple, has strong repeatability, high utilization rate of raw materials, mild reaction conditions, no need of heating reaction and high-temperature roasting, no need of repeated washing, low preparation cost and reduced generation of waste gas and waste water.
Drawings
FIG. 1 is a graph showing the removal rate of formaldehyde by the gold catalyst of the present invention;
fig. 2 is a graph of the removal rate of carbon monoxide by the gold catalyst of the present invention.
Detailed Description
The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
Example 1
This embodiment provides a gold catalyst and a preparation method thereof, where the preparation method includes the following steps:
(1) adjusting the pH of the chloroauric acid solution to the final pH of 10 to obtain an alkaline gold solution;
(2) adding CeO2Mixing a carrier with the alkaline gold solution in the step (1), and standing and reacting for 18 days at the pH of 10 and the temperature of 25 ℃ to obtain a supernatant and a gold catalyst; drying the obtained gold catalyst for 4 hours at 60 ℃; recycling the obtained supernatant to the step (1) as a chloroauric acid solution;
wherein, CeO2The mass ratio of the carrier to the chloroauric acid in the chloroauric acid solution in the step (1) is 1: 0.05.
The gold catalyst obtained in this example was tested for its removal of formaldehyde and carbon monoxide by the following methods:
50mg of gold is addedThe catalyst is placed in a quartz flow reactor of a fixed bed, reaction gas containing formaldehyde is introduced for reaction, and the initial concentration of the formaldehyde in the reaction gas is X0Sampling at 1h, 2h, 3h, 4h, 5h and 6h to test the concentration of residual formaldehyde, noted as Xi(i-1, 2, 3, 4, 5, 6), the formaldehyde removal rate, i.e., the formaldehyde removal rate (1-X), was obtained by calculationi/X0) X100% where X0＝100ppm；
50mg of gold catalyst is placed in a quartz flow reactor of a fixed bed, reaction gas containing carbon monoxide is introduced for reaction, and the initial concentration of the carbon monoxide in the reaction gas is Y0Samples were taken at 1h, 2h, 3h, 4h, 5h and 6h for the residual carbon monoxide concentration, noted Yi(i-1, 2, 3, 4, 5, 6), the carbon monoxide removal rate, that is, (1-Y) can be obtained by calculationi/Y0) X 100% where Y0＝100ppm；
The results of the test for formaldehyde removal rate of the gold catalyst obtained in this example are shown in table 1 and fig. 1, and the results of the test for carbon monoxide removal rate of the gold catalyst obtained in this example are shown in table 1 and fig. 2.
TABLE 1
Figure BDA0003411917070000081
Example 2
This embodiment provides a gold catalyst and a preparation method thereof, where the preparation method includes the following steps:
(1) adjusting the pH of the chloroauric acid solution to the end point pH of 9 to obtain an alkaline gold solution;
(2) adding TiO into the mixture2Mixing a carrier with the alkaline gold solution in the step (1), and standing and reacting for 14 days at the pH of 9 and the temperature of 30 ℃ to obtain a supernatant and a gold catalyst; drying the obtained gold catalyst for 8 hours at 40 ℃; recycling the obtained supernatant to the step (1) as a chloroauric acid solution;
wherein, TiO2The mass ratio of the carrier to the chloroauric acid in the chloroauric acid solution in the step (1) is 1: 0.0002.
Example 3
This embodiment provides a gold catalyst and a preparation method thereof, where the preparation method includes the following steps:
(1) adjusting the pH of the chloroauric acid solution to the end point pH of 11 to obtain an alkaline gold solution;
(2) mixing Al2O3Mixing a carrier with the alkaline gold solution in the step (1), and standing and reacting for 20 days at the temperature of 20 ℃ and the pH value of 8 to obtain a supernatant and a gold catalyst; drying the obtained gold catalyst for 6h at 50 ℃; recycling the obtained supernatant to the step (1) as a chloroauric acid solution;
wherein, Al2O3The mass ratio of the carrier to the chloroauric acid in the chloroauric acid solution in the step (1) is 1: 0.1.
Example 4
This example provides a gold catalyst and a method of making the same, with reference to the method of making described in example 1, except that: standing for 5 days in the step (2); namely, the preparation method comprises the steps of:
(1) adjusting the pH of the chloroauric acid solution to the final pH of 10 to obtain an alkaline gold solution;
(2) adding CeO2Mixing a carrier with the alkaline gold solution in the step (1), and standing and reacting for 5 days at the pH of 10 and the temperature of 25 ℃ to obtain a supernatant and a gold catalyst; drying the obtained gold catalyst for 4 hours at 60 ℃; recycling the obtained supernatant to the step (1) as a chloroauric acid solution;
wherein, CeO2The mass ratio of the carrier to the chloroauric acid in the chloroauric acid solution in the step (1) is 1: 0.05.
Example 5
This example provides a gold catalyst and a method of making the same, with reference to the method of making described in example 1, except that: the standing reaction time in the step (2) is 36 days; namely, the preparation method comprises the steps of:
(1) adjusting the pH of the chloroauric acid solution to the final pH of 10 to obtain an alkaline gold solution;
(2) adding CeO2Mixing the carrier with the alkaline gold solution in the step (1), and standing at the pH of 10 and the temperature of 25 ℃ for reactionObtaining supernatant and a gold catalyst after 36 days; drying the obtained gold catalyst for 4 hours at 60 ℃; recycling the obtained supernatant to the step (1) as a chloroauric acid solution;
wherein, CeO2The mass ratio of the carrier to the chloroauric acid in the chloroauric acid solution in the step (1) is 1: 0.05.
Comparative example 1
This comparative example provides a gold catalyst and a method of making the same, with reference to the method of making described in example 1, except that: roasting after standing reaction; namely, the preparation method comprises the steps of:
(1) adjusting the pH of the chloroauric acid solution to the final pH of 10 to obtain an alkaline gold solution;
(2) adding CeO2Mixing a carrier with the alkaline gold solution in the step (1), and standing and reacting for 18 days at the pH of 10 and the temperature of 25 ℃ to obtain a supernatant and a gold catalyst; drying the obtained gold catalyst for 4h at 60 ℃, and roasting for 2h at 300 ℃; recycling the obtained supernatant to the step (1) as a chloroauric acid solution;
wherein, CeO2The mass ratio of the carrier to the chloroauric acid in the chloroauric acid solution in the step (1) is 1: 0.05.
Comparative example 2
This comparative example provides a gold catalyst and a method for its preparation, prepared with reference to the preparation method described in CN 110721680A.
Firstly, the gold catalysts obtained in the above examples and comparative examples are tested for the removal rate of formaldehyde and carbon monoxide by the following test methods:
50mg of gold catalyst is placed in a quartz flow reactor of a fixed bed, reaction gas containing formaldehyde or carbon monoxide is introduced for reaction for 2 hours, and the initial concentration of the formaldehyde or the carbon monoxide in the reaction gas is C0And after reaction, the concentration is C1The removal rate of formaldehyde or carbon monoxide is then (1-C)1/C0)×100％。
The results of the test of the removal rates of formaldehyde and carbon monoxide by the gold catalysts obtained in the above examples and comparative examples are shown in table 2.
Second, the exhaust gas and waste water detection was performed during the preparation of the gold catalysts in the above examples and comparative examples, and the detection method was as follows:
when detecting waste gas, detecting the waste gas by using an inorganic waste gas detector; when wastewater is detected, the amount of wastewater produced is recorded.
The results of the exhaust gas and wastewater tests of the above examples and comparative examples are shown in Table 2.
TABLE 2
Figure BDA0003411917070000111
The following points can be found from table 2:
(1) as can be seen from examples 1-3, the gold catalyst of the present invention has excellent formaldehyde and carbon monoxide oxidation performance, the formaldehyde removal rate reaches more than 90%, and the carbon monoxide removal rate reaches more than 45%;
(2) comparing example 1 with examples 4 and 5, it can be seen that, since the standing reaction time in step (2) in example 4 is 5 days, which is less than the preferable 7-31 days of the present invention, the interaction between gold and the carrier is weak, gold cannot be sufficiently precipitated on the surface of the carrier, and the dispersion degree of gold is poor, which in turn results in the performance degradation of the gold catalyst, and the formaldehyde removal rate and the carbon monoxide removal rate are reduced; since the standing reaction time in step (2) in example 5 is 36 days, beyond the preferable 7-31 days of the invention, the catalyst can be changed under the action of air, the valence state and the particle size of gold are changed, the performance of the catalyst is reduced, and the removal rate of formaldehyde and carbon monoxide is reduced;
(3) comparing example 1 with comparative example 1, it can be seen that, since comparative example 1 is calcined after standing reaction, the catalytic performance of the gold catalyst is not much different from that of example 1, but comparative example 1 generates exhaust gas during calcination, causing pollution;
(4) comparing example 1 with comparative example 2, it can be seen that, in comparative example 2, the gold catalyst is washed for a plurality of times, the amount of wastewater generated is large, and environmental pollution is easily caused in practical application.
The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.

Claims (10)

1. A preparation method of a gold catalyst is characterized by comprising the following steps:
(1) adjusting the pH value of the gold source solution to be alkaline to obtain an alkaline gold solution;
(2) and (2) mixing the carrier with the alkaline gold solution in the step (1) and then carrying out standing reaction to obtain a supernatant and a gold catalyst.
2. The method for preparing a gold catalyst according to claim 1, wherein the gold source solution in the step (1) is an aqueous solution of chloroauric acid.
3. The method for producing a gold catalyst according to claim 1 or 2, wherein the end point pH of the pH adjustment in step (1) is 9 to 11.
4. The method for producing a gold catalyst according to any one of claims 1 to 3, wherein the carrier in the step (2) comprises TiO2，CeO2Or Al2O3Any one or a combination of at least two of;
preferably, the mass ratio of the carrier in the step (2) to the gold source in the gold source solution in the step (1) is 1 (0.0002-0.1).
5. The method for preparing a gold catalyst according to any one of claims 1 to 4, wherein the pH environment of the standing reaction in the step (2) is 8 to 10;
preferably, the temperature of the standing reaction in the step (2) is 20-30 ℃;
preferably, the standing reaction time of the step (2) is 7 to 31 days.
6. The method for preparing a gold catalyst according to any one of claims 1 to 5, further comprising: drying the gold catalyst obtained in the step (2);
preferably, the drying temperature is 40-60 ℃;
preferably, the drying time is 2-16 h.
7. The method for preparing a gold catalyst according to any one of claims 1 to 6, wherein the supernatant obtained in step (2) is recycled to step (1) as the gold source solution.
8. The method for preparing a gold catalyst according to any one of claims 1 to 7, comprising the steps of:
(1) adjusting the pH of the chloroauric acid solution to the end point pH of 9-11 to obtain an alkaline gold solution;
(2) mixing a carrier with the alkaline gold solution obtained in the step (1), and standing and reacting for 7-31 days at the pH of 8-10 and the temperature of 20-30 ℃ to obtain a supernatant and a gold catalyst; drying the obtained gold catalyst for 2-16h at 40-60 ℃; recycling the obtained supernatant to the step (1) as a chloroauric acid solution;
wherein the support comprises TiO2，CeO2Or Al2O3Any one or a combination of at least two of; the mass ratio of the carrier to the chloroauric acid in the chloroauric acid solution in the step (1) is 1 (0.0002-0.1).
9. A gold catalyst obtained by the production method according to any one of claims 1 to 8, wherein the content of gold element in the gold catalyst is 0.01 to 5 wt%.
10. Use of a gold catalyst according to claim 9 for the removal of formaldehyde and/or carbon monoxide.
CN202111534004.4A 2021-12-15 2021-12-15 Gold catalyst, preparation method and application thereof Pending CN114100610A (en)

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Publication number Priority date Publication date Assignee Title
US20040087443A1 (en) * 2002-10-30 2004-05-06 Toyota Jidosha Kabushiki Kaisha Support for an exhaust gas purification catalyst and production method
US20070219090A1 (en) * 2004-07-06 2007-09-20 Michael Bowker Supported gold catalysts
CN101198403A (en) * 2005-01-04 2008-06-11 3M创新有限公司 Heterogeneous, composite, carbonaceous catalyst system and methods that use catalytically active gold
CN103301853A (en) * 2013-06-20 2013-09-18 武汉大学 Gold catalyst removing carbon monoxide, formaldehyde and ethylene and preparation and application
CN103599777A (en) * 2013-11-26 2014-02-26 中国科学院福建物质结构研究所 Gold-base catalyst for room-temperature carbon monoxide removal and preparation method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040087443A1 (en) * 2002-10-30 2004-05-06 Toyota Jidosha Kabushiki Kaisha Support for an exhaust gas purification catalyst and production method
US20070219090A1 (en) * 2004-07-06 2007-09-20 Michael Bowker Supported gold catalysts
CN101198403A (en) * 2005-01-04 2008-06-11 3M创新有限公司 Heterogeneous, composite, carbonaceous catalyst system and methods that use catalytically active gold
CN103301853A (en) * 2013-06-20 2013-09-18 武汉大学 Gold catalyst removing carbon monoxide, formaldehyde and ethylene and preparation and application
CN103599777A (en) * 2013-11-26 2014-02-26 中国科学院福建物质结构研究所 Gold-base catalyst for room-temperature carbon monoxide removal and preparation method thereof

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