CN114797438B - Formaldehyde scavenger, preparation method and application thereof - Google Patents
Formaldehyde scavenger, preparation method and application thereof Download PDFInfo
- Publication number
- CN114797438B CN114797438B CN202210446514.4A CN202210446514A CN114797438B CN 114797438 B CN114797438 B CN 114797438B CN 202210446514 A CN202210446514 A CN 202210446514A CN 114797438 B CN114797438 B CN 114797438B
- Authority
- CN
- China
- Prior art keywords
- formaldehyde
- formaldehyde scavenger
- filter cake
- water
- stirring
- 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.)
- Active
Links
Images
Classifications
-
- 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
- B01D53/81—Solid phase processes
-
- 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
- B01D53/46—Removing components of defined structure
- B01D53/72—Organic compounds not provided for in groups B01D53/48 - B01D53/70, e.g. 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
-
- 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
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/24—Nitrogen compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
- B01D2253/10—Inorganic adsorbents
- B01D2253/106—Silica or silicates
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/10—Noble metals or compounds thereof
- B01D2255/102—Platinum group metals
- B01D2255/1021—Platinum
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/20—Metals or compounds thereof
- B01D2255/206—Rare earth metals
- B01D2255/2065—Cerium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/70—Organic compounds not provided for in groups B01D2257/00 - B01D2257/602
- B01D2257/708—Volatile organic compounds V.O.C.'s
-
- 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
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
The invention discloses a formaldehyde scavenger, a preparation method and application thereof. The preparation method grows platinum on the nitrogen doped ceria/activated diatomite composite material to obtain the formaldehyde scavenger. The formaldehyde scavenger prepared by the invention improves the adsorption effect of formaldehyde molecules on the surface of the scavenger, further promotes the catalytic degradation, effectively converts the formaldehyde molecules into carbon dioxide, and does not generate toxic and harmful substances. The formaldehyde scavenger prepared by the invention is applied to a closed room, has excellent formaldehyde removal performance and can be used for a long time.
Description
Technical Field
The invention belongs to the field of environment-friendly materials, and particularly relates to a formaldehyde scavenger, a preparation method and application thereof.
Background
The development of industry obviously improves the living standard of people, but along with the wide application of chemical raw materials such as urea-formaldehyde resin and the like, the industry brings harm to people and excessive formaldehyde in the environment. Formaldehyde is a protoplasmic toxin that can bind to proteins and cause allergic reactions in the local skin and even throughout the body. The damage caused by formaldehyde to humans can vary from person to person. The most sensitive to formaldehyde is the human eye, and secondly the respiratory system, where the respiratory tract is most vulnerable to formaldehyde. Formaldehyde, on the other hand, is a hapten which binds to proteins in the human body to form antigens, causing skin diseases such as allergic dermatitis. When a human body is contacted with formaldehyde for a long time, anaphylactic reaction and abnormal smell occur, the immune function and the cardiopulmonary respiratory function of the human body are seriously affected, and various complications such as inappetence, night sweating, belly swelling and pain, irregular pulse, dermatitis, weakness, irregular change of body temperature, eczema, red swelling, headache and the like appear. In severe cases, it can cause allergies and ulcers in skin tissue, and even cancerous changes. Formaldehyde has also been reported in the modern journal of medicine to cause mutations in genes in the nucleus and to cause leukemias and chromosomal abnormalities. The harm to the old, the weak, the pregnant and the children is the greatest.
Houses are the most important workplace and living places for people, where most of the time people spend. After house decoration, formaldehyde is overproof and has a certain pungent smell. Formaldehyde is highly toxic and is identified by the world health organization as a carcinogenic and teratogenic substance. Formaldehyde exceeding the standard seriously jeopardizes the health of people, and causes a series of problems such as respiratory diseases, neonatal physique reduction, chromosome abnormality, leukemia and the like.
Usually, people choose to ventilate and empty a newly-installed house for a period of time and use a formaldehyde scavenger for treatment, so as to achieve the purpose of removing formaldehyde; the formaldehyde release period of the finishing material is as long as 3 to 15 years, so that the indoor formaldehyde can be quickly and effectively removed, and the finishing material is necessary for physical and mental health of people.
CN 103143231A discloses a crystalline formaldehyde scavenger for decoration, which consists of 10-15 parts of attapulgite, 10-15 parts of bentonite, 10-15 parts of sepiolite, 2-4 parts of diatomite, 10-15 parts of zeolite, 10-15 parts of zirconium phosphate and 10-15 parts of nano titanium dioxide; the invention has strong air purifying effect and strong formaldehyde removing effect. CN 104874267A discloses a formaldehyde scavenger, which consists of bentonite 4-8 parts, tea polyphenol 0.5-1.5 parts, amino acid 1-3 parts, sodium sulfate-hydrogen peroxide-sodium chloride adduct 80-90 parts, anatase titanium dioxide 1-5 parts, sodium dodecyl benzene sulfonate 1-5 parts; the invention is healthy and environment-friendly, and can effectively remove formaldehyde. CN 104492023A discloses a formaldehyde scavenger comprising 65-70% of lysimachia foenum-graecum powder, 25-25% of ammonium bicarbonate and CaCl 2 5-10%, and can effectively remove formaldehyde in rooms, automobiles and furniture.
The method is simple to operate, has a good effect on removing formaldehyde in a short period, but slowly releases formaldehyde in the finishing material. The existing formaldehyde scavenger can be used for rapidly removing formaldehyde, the indoor formaldehyde content can be slowly increased after a period of time, and the formaldehyde scavenger needs to be replaced by a new formaldehyde scavenger, so that the formaldehyde scavenger is remarkable in long-acting formaldehyde removal performance. The prior art lacks an assessment of formaldehyde degradation products and many catalysts, while capable of reducing formaldehyde content in the room, may produce irritating formic acid and toxic and hazardous carbon monoxide. Therefore, it is necessary to develop a formaldehyde scavenger that is efficient, maintains long-term formaldehyde removal, while evaluating its catalytic formaldehyde formation products.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, the present invention has an object to provide a formaldehyde scavenger capable of rapidly and effectively removing formaldehyde and maintaining stable removal performance for a long period of time, and to evaluate the product of catalyzing formaldehyde.
In order to achieve the above purpose, the invention provides a preparation method of formaldehyde scavenger, comprising the following steps:
step 1: dispersing activated diatomite, a nitrogen source and a cerium source in water under stirring to form uniform suspension I;
step 2: dropwise adding the reaction solution into the suspension I which is continuously stirred, stirring for reaction, filtering to obtain a filter cake, washing and drying; calcining the dried filter cake, naturally cooling, crushing and sieving to obtain cerium oxide/activated diatomite composite powder;
step 3: uniformly dispersing the cerium dioxide/activated diatomite composite powder obtained in the step 2 in water under ultrasound to form a suspension II; adding chloroplatinic acid into the suspension which is continuously stirred, and continuously stirring; adding a reducing agent solution for reaction, and carrying out suction filtration, washing and drying to obtain the formaldehyde scavenger.
Preferably, in the step 1, the weight ratio of the activated diatomite to the nitrogen source to the cerium source to the water is 100: (1-5): (10-20): 1000; the nitrogen source is one of urea, dicyandiamide and glycine; the cerium source is cerium nitrate hexahydrate; the stirring speed is 300-500 r/min, and the stirring time is 1-3 h; the preparation method of the activated diatomite comprises the following steps: 10 to 20 parts of diatomite with 500 to 1000 meshes is placed in 100 to 300 parts of hydrochloric acid or nitric acid aqueous solution with 0.5mol/L to 3mol/L for soaking for 1 to 3 hours; washing with water until the pH value of the supernatant is 6.5-7.5, suction filtering, putting the filter cake into a constant temperature oven, drying at 60-100 ℃ for 3-5 h, crushing the filter cake, sieving with a 500-1000 mesh sieve, and collecting the powder of the sieve to obtain the activated diatomite.
Preferably, the reaction solution in the step 2 is one of sodium hydroxide, ammonia water, sodium carbonate and sodium bicarbonate aqueous solution, the concentration is 0.6-2 mol/L, and the weight ratio of the reaction solution to water in the suspension is 1: (10-20); the dripping is carried out by putting into a constant pressure funnel at a speed of 10-30 g/min; the stirring speed of the suspension I is 300-500 r/min; the washing is carried out three times by ethanol and water respectively; the drying is to put the filter cake into a constant temperature oven to be dried for 3 to 5 hours at the temperature of between 60 and 100 ℃; the calcination temperature is 500-700 ℃ and the calcination time is 3-5 h; the sieving is carried out by sieving with a 500-1000 mesh sieve, and the powder passing through the sieve is collected.
Preferably, the ultrasonic power in the step 3 is 50-200W, the frequency is 20-130 KHz, the temperature is 20-40 ℃ and the time is 20-60 min; the stirring speed is 300-500 r/min; the weight ratio of the ceria/diatomite composite material to the water to the chloroplatinic acid to the reducing agent solution is 10:100: (0.1-0.5): (1-5), wherein the reducer solution is ascorbic acid water solution with the concentration of 0.5-1 mol/L; adding the reducer solution, and then continuing to react for 1-2 h at the stirring rate of 300-500 r/min; the washing is carried out three times by ethanol and water respectively; and the drying is to put the materials into a constant temperature oven to be dried for 3 to 5 hours at the temperature of between 60 and 100 ℃.
Preferably, the dried filter cake in the step 3 can be crushed into powder or processed and molded by a granulator and filled into a breathable non-woven fabric bag for being matched with different scenes; the crushing is to crush the dry filter cake, pass through a 500-1000 mesh screen, and collect the powder passing through the screen to obtain formaldehyde scavenger powder; the granulating process is to put the dry filter cake into a granulator to prepare a sphere with the diameter of 8-20 mm or a column with the diameter of 6mm and the height of 10 mm.
Another aspect of the present invention provides the use of the formaldehyde scavenger described above:
and (3) measuring the formaldehyde concentration of the newly-installed house after sealing, placing the formaldehyde scavenger for a period of time, and testing the formaldehyde concentration of the closed environment. The house surfaceThe product is 20-30 m 2 The method comprises the steps of carrying out a first treatment on the surface of the Uniformly placing the breathable non-woven fabric bag filled with formaldehyde scavenger into a closed house, wherein the application density is 2-5 g/m 2 。
The formaldehyde concentration test method is based on the second part of GB/T18204.2-2014 public health detection method, namely chemical pollutant, and uses phenol reagent spectrophotometry to test formaldehyde or uses infrared sound gas monitor to detect formaldehyde.
The invention has the beneficial effects that:
1. the invention provides a preparation method of a novel formaldehyde scavenger, which is characterized in that cerium dioxide, nitrogen doping and metal platinum are introduced into activated diatomite, so that the degradation and removal capacity of a composite material to formaldehyde is remarkably improved, the dispersibility of the metal platinum is enhanced by the nitrogen doping, and the oxygen vacancies of the cerium dioxide, active oxygen species gathered on the surface of the metal platinum and the larger specific surface area of the diatomite produce synergistic effect, so that the composite material has extremely high degradation capacity to formaldehyde at room temperature.
2. The preparation method is simple, formaldehyde can be effectively removed, the effective acting time is more than half a year, the formaldehyde can be processed into different shapes according to the needs, and the formaldehyde remover is very convenient to use in cooperation with different use scenes.
Drawings
FIG. 1 variation of formaldehyde conversion at different relative humidities for formaldehyde scavengers prepared in example 3.
Detailed Description
The description of part of raw materials used in the invention is as follows:
diatomite is a biologically deposited silicalite, and is formed by long-term natural environment effect of remains of diatomite, and contains SiO as main ingredient 2 Amorphous protein minerals of (a) are present; diatomite is nontoxic and odorless, exists in a large amount in natural environment, has higher purity, and has lower cost, and the price is about one twentieth of the price of the activated carbon; kieselguhr can be divided into: the diatomite also contains oxides of metal ions such as aluminum oxide, ferric oxide and the like; kieselguhr factorThe wall shell is composed of a plurality of multilevel, large and orderly arranged micropores, has the characteristics of light weight, large holes, large specific surface area, strong adsorption capacity and stable chemical property (basically insoluble except hydrofluoric acid and strong alkali under high temperature and high pressure), is widely used as a reaction catalyst, a filling agent, a heat insulating material, a filtering material and the like, the surface of kieselguhr is covered by a large amount of silicon hydroxyl groups, the kieselguhr has close relation with the adsorption property, besides the silicon hydroxyl groups, the surface of the kieselguhr also contains a large amount of hydroxyl groups, and the kieselguhr used in the invention is collected in the river-facing region of Jilin province and comprises the main components of silicon dioxide, aluminum oxide, ferric oxide, calcium oxide and magnesium oxide;
cerium nitrate hexahydrate, chemical formula of Ce (NO) 3 ) 3 ·6H 2 O, inorganic oxidant, when meeting the flammable thing and catching fire, can promote the fire; mixing with reducing agent, organic matter, inflammable matter such as sulfur, phosphorus or metal powder to form explosive mixture, and releasing toxic nitrogen oxide gas at Wen Shifen%; industrial products are reddish, deliquescent and possibly harmful to the environment, and have accumulation effect in underground water, and are used as a steam lamp gauze cover additive and a petrochemical catalyst, are raw materials for preparing cerium salt, are used as an analysis reagent in analytical chemistry and are also used in the pharmaceutical industry, and cerium nitrate hexahydrate used by the invention is purchased in national pharmaceutical chemical reagent company;
glycine, also known as glycine, is a non-essential amino acid of the formula C 2 H 5 NO 2 Solid glycine is white to off-white crystalline powder, odorless, nontoxic, soluble in water, and practically insoluble in ethanol or diethyl ether; the glycine is used for pharmaceutical industry, biochemical test and organic synthesis, is the amino acid with the simplest structure, has acidic and alkaline functional groups in the molecule, can ionize in water, has strong hydrophilicity, belongs to nonpolar amino acid, is dissolved in polar solvent and indissolvable in nonpolar solvent, has higher boiling point and melting point, and can be made to take different molecular forms through the adjustment of the acidity and alkalinity of aqueous solution;
chloroplatinic acid of the formula H 2 PtCl 6 ·6H 2 O, also called hexachloroplatinic (IV) acid, contains six crystal waters, is orange yellow powder or reddish brown crystal, is deliquescent, is dissolved in water, ethanol and acetone, and is an active ingredient of a hydrogenation dehydrogenation catalyst in petrochemical industry; the chloroplatinic acid used in the invention is purchased from national pharmaceutical group chemical reagent company, which is commonly used as a chemical reagent and catalyst, the precipitation of alkaloid, the preparation of noble metal catalyst and the coating of noble metal;
ascorbic acid, also known as vitamin C, is a polyhydroxy compound of the formula C 6 H 8 O 6 The structure is similar to glucose, and two adjacent enol type hydroxyl groups at the 2 nd and 3 rd positions in the molecule are easy to be dissociated to release H + The ascorbic acid has acid property, namely L-ascorbic acid, wherein the ascorbic acid has lactone ring and 2 chiral carbon atoms, is active in property, has optical activity and strong reducibility, is easily oxidized into dehydroascorbic acid, is white crystal or crystalline powder, has no odor, is sour, is gradually yellow after long-term color setting, is easy to dissolve in water and acidic, is slightly soluble in ethanol, and is insoluble in chloroform or diethyl ether;
the present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
EXAMPLE 1 preparation of Formaldehyde scavenger
100g of activated diatomite, 5g of urea and 20g of cerium nitrate hexahydrate are dispersed in 1000g of water and stirred for 1h at a stirring rate of 500r/min to form a uniform suspension I; 100g of 0.6mol/L aqueous ammonia solution is placed in a constant pressure funnel and is added into a suspension I stirred at a stirring rate of 500r/min in a dropwise manner at a rate of 20g/min, the stirring reaction is continued for 2h, suction filtration is carried out, ethanol and water are used for washing three times respectively, and a filter cake is transferred to a constant temperature oven and dried for 3h at 80 ℃ to obtain a dried filter cake; calcining the dried filter cake in a muffle furnace at 600 ℃ for 2 hours, naturally cooling, crushing the calcined filter cake, sieving the filter cake with a 500-mesh sieve, and collecting powder under the sieve to obtain cerium oxide/diatomite composite material powder;
dispersing 10g of cerium dioxide/activated diatomite composite powder in 100g of water at the ultrasonic power of 100W, the frequency of 50KHz and the temperature of 25 ℃ to form uniform suspension II; continuously stirring the suspension II at a stirring rate of 500r/min, adding 0.5g of chloroplatinic acid into the continuously stirred suspension II, continuously stirring and dispersing for 1h, adding 5g of 0.5mol/L ascorbic acid aqueous solution, and continuously stirring at 500r/min for reacting for 2h; filtering, washing with ethanol and water for three times, transferring the filter cake to a constant temperature oven, and drying at 80 ℃ for 3 hours to obtain a dried filter cake, crushing the dried filter cake, sieving with a 500-mesh sieve, and collecting powder under the sieve to obtain the formaldehyde scavenger prepared in the embodiment;
the preparation method of the activated diatomite comprises the following steps: 100g of 500-mesh diatomite is placed in 1000g of 2mol/L hydrochloric acid for soaking for 3 hours; washing with water until the pH of the supernatant is 7.0, filtering, putting the filter cake into a constant temperature oven, drying at 100 ℃ for 4 hours, crushing the filter cake, sieving with a 500-mesh sieve, and collecting the powder passing through the sieve to obtain the activated diatomite.
EXAMPLE 2 preparation of Formaldehyde scavenger
100g of activated diatomite, 5g of dicyandiamide and 20g of cerium nitrate hexahydrate are dispersed in 1000g of water and stirred for 1h at a stirring rate of 500r/min to form a uniform suspension I; 100g of 0.6mol/L aqueous ammonia solution is placed in a constant pressure funnel and is added into a suspension I stirred at a stirring rate of 500r/min in a dropwise manner at a rate of 20g/min, the stirring reaction is continued for 2h, suction filtration is carried out, ethanol and water are used for washing three times respectively, and a filter cake is transferred to a constant temperature oven and dried for 3h at 80 ℃ to obtain a dry filter cake; calcining the dried filter cake in a muffle furnace at 600 ℃ for 2 hours, naturally cooling, crushing the calcined filter cake, sieving the filter cake with a 500-mesh sieve, and collecting powder under the sieve to obtain cerium oxide/activated diatomite composite material powder;
dispersing 10g of cerium dioxide/activated diatomite composite powder in 100g of water at the ultrasonic power of 100W, the frequency of 50KHz and the temperature of 25 ℃ to form uniform suspension II; continuously stirring the suspension II at a stirring rate of 500r/min, adding 0.5g of chloroplatinic acid into the continuously stirred suspension II, continuously stirring and dispersing for 1h, adding 5g of 0.5mol/L ascorbic acid aqueous solution, and continuously stirring at 500r/min for reacting for 2h; filtering, washing with ethanol and water for three times, transferring the filter cake to a constant temperature oven, and drying at 80 ℃ for 3 hours to obtain a dried filter cake, crushing the dried filter cake, sieving with a 500-mesh sieve, and collecting powder under the sieve to obtain the formaldehyde scavenger prepared in the embodiment;
the preparation method of the activated diatomite is the same as that of example 1.
EXAMPLE 3 preparation of Formaldehyde scavenger
100g of activated diatomite, 5g of glycine and 20g of cerium nitrate hexahydrate are dispersed in 1000g of water and stirred for 1h at a stirring rate of 500r/min to form a uniform suspension I; 100g of 0.6mol/L aqueous ammonia solution is placed in a constant pressure funnel and is added into a suspension I stirred at a stirring rate of 500r/min in a dropwise manner at a rate of 20g/min, the stirring reaction is continued for 2h, suction filtration is carried out, ethanol and water are used for washing three times respectively, and a filter cake is transferred to a constant temperature oven and dried for 3h at 80 ℃ to obtain a dry filter cake; calcining the dried filter cake in a muffle furnace at 600 ℃ for 2 hours, naturally cooling, crushing the calcined filter cake, sieving the filter cake with a 500-mesh sieve, and collecting powder under the sieve to obtain cerium oxide/activated diatomite composite material powder;
dispersing 10g of cerium dioxide/activated diatomite composite powder in 100g of water at the ultrasonic power of 100W, the frequency of 50KHz and the temperature of 25 ℃ to form uniform suspension II; continuously stirring the suspension II at a stirring rate of 500r/min, adding 0.5g of chloroplatinic acid into the continuously stirred suspension II, continuously stirring and dispersing for 1h, adding 5g of 0.5mol/L ascorbic acid aqueous solution, and continuously stirring at 500r/min for reacting for 2h; filtering, washing with ethanol and water for three times, transferring the filter cake to a constant temperature oven, and drying at 80 ℃ for 3 hours to obtain a dried filter cake, crushing the dried filter cake, sieving with a 500-mesh sieve, and collecting powder under the sieve to obtain the formaldehyde scavenger prepared in the embodiment;
the preparation method of the activated diatomite is the same as that of example 1.
Comparative example 1 preparation of Formaldehyde scavenger
100g of activated diatomite and 20g of cerium nitrate hexahydrate are dispersed in 1000g of water, and stirred for 1h at a stirring rate of 500r/min to form a uniform suspension I; 100g of 0.6mol/L aqueous ammonia solution is placed in a constant pressure funnel and is added into a suspension I stirred at a stirring rate of 500r/min in a dropwise manner at a rate of 20g/min, the stirring reaction is continued for 2h, suction filtration is carried out, ethanol and water are used for washing three times respectively, and a filter cake is transferred to a constant temperature oven and dried for 3h at 80 ℃ to obtain a dry filter cake; calcining the dried filter cake in a muffle furnace at 600 ℃ for 2 hours, naturally cooling, crushing the calcined filter cake, sieving the filter cake with a 500-mesh sieve, and collecting powder under the sieve to obtain cerium oxide/activated diatomite composite material powder;
dispersing 10g of cerium dioxide/activated diatomite composite powder in 100g of water for ultrasonic treatment for 1h under the conditions that the ultrasonic power is 100W, the frequency is 50KHz and the temperature is 25 ℃ to form uniform suspension II; continuously stirring the suspension II at a stirring rate of 500r/min, adding 0.5g of chloroplatinic acid into the continuously stirred suspension II, continuously stirring and dispersing for 1h, adding 5g of 0.5mol/L ascorbic acid aqueous solution, and continuously stirring at 500r/min for reacting for 2h; filtering, washing with ethanol and water for three times, transferring the filter cake to a constant temperature oven, and drying at 80 ℃ for 3 hours to obtain a dried filter cake, crushing the dried filter cake, sieving with a 500-mesh sieve, and collecting powder under the sieve to obtain the formaldehyde scavenger prepared in the embodiment;
the preparation method of the activated diatomite is the same as that of example 1.
Comparative example 2 preparation of Formaldehyde scavenger
100g of 500-mesh diatomite, 5g of glycine and 20g of cerium nitrate hexahydrate are dispersed in 1000g of water, and stirred for 1h at a stirring rate of 500r/min to form a uniform suspension I; 100g of 0.6mol/L aqueous ammonia solution is placed in a constant pressure funnel and is added into a suspension I stirred at a stirring rate of 500r/min in a dropwise manner at a rate of 20g/min, the stirring reaction is continued for 2h, suction filtration is carried out, ethanol and water are used for washing three times respectively, and a filter cake is transferred to a constant temperature oven and dried for 3h at 80 ℃ to obtain a dry filter cake; calcining the dried filter cake in a muffle furnace at 600 ℃ for 2 hours, naturally cooling, crushing the calcined filter cake, sieving the filter cake with a 500-mesh sieve, and collecting powder under the sieve to obtain cerium oxide/diatomite composite material powder;
dispersing 10g of cerium oxide/diatomite composite powder in 100g of water for ultrasonic treatment for 1h under the conditions that the ultrasonic power is 100W, the frequency is 50KHz and the temperature is 25 ℃ to form uniform suspension II; continuously stirring the suspension II at a stirring rate of 500r/min, adding 0.5g of chloroplatinic acid into the continuously stirred suspension II, continuously stirring and dispersing for 1h, adding 5g of 0.5mol/L ascorbic acid aqueous solution, and continuously stirring at 500r/min for reacting for 2h; and (3) carrying out suction filtration, washing with ethanol and water for three times, transferring the filter cake to a constant temperature oven, drying at 80 ℃ for 3 hours to obtain a dried filter cake, crushing the dried filter cake, sieving the filter cake with a 500-mesh sieve, and collecting powder under the sieve to obtain the formaldehyde scavenger prepared in the embodiment.
Comparative example 3 preparation of a Formaldehyde scavenger
100g of activated diatomite, 5g of glycine and 20g of cerium nitrate hexahydrate are dispersed in 1000g of water and stirred for 1h at a stirring rate of 500r/min to form a uniform suspension I; 100g of 0.6mol/L aqueous ammonia solution is placed in a constant pressure funnel and is added into a suspension I stirred at a stirring rate of 500r/min in a dropwise manner at a rate of 20g/min, the stirring reaction is continued for 2h, suction filtration is carried out, ethanol and water are used for washing three times respectively, and a filter cake is transferred to a constant temperature oven and dried for 3h at 80 ℃ to obtain a dry filter cake; calcining the dried filter cake in a muffle furnace at 600 ℃ for 2 hours, naturally cooling, crushing the calcined filter cake, sieving the filter cake with a 500-mesh sieve, and collecting powder under the sieve to obtain the formaldehyde scavenger prepared in the comparative example;
the preparation method of the activated diatomite is the same as that of example 1.
Comparative example 4 preparation of a Formaldehyde scavenger
Dispersing 100g of activated diatomite and 5g of glycine in 1000g of water for ultrasonic treatment for 1h under the conditions that the ultrasonic power is 100W, the frequency is 50KHz and the temperature is 25 ℃ to form uniform suspension I; the suspension I is prepared; continuously stirring at the stirring rate of 500r/min, adding 0.5g of chloroplatinic acid into the continuously stirred suspension II, continuously stirring and dispersing for 1h, adding 5g of 0.5mol/L ascorbic acid aqueous solution, and continuously stirring at the stirring rate of 500r/min for 2h; and (3) carrying out suction filtration, washing with ethanol and water for three times, transferring the filter cake to a constant temperature oven, drying at 80 ℃ for 3 hours to obtain a dried filter cake, crushing the dried filter cake, sieving the filter cake with a 500-mesh sieve, and collecting powder under the sieve to obtain the formaldehyde scavenger prepared in the embodiment.
Test example 1 analysis of catalytic Performance of Formaldehyde scavenger
The degradation test of formaldehyde is carried out in a self-made reaction box, the size of the reaction box is 20cm multiplied by 40cm, the material of the reaction box is opaque, formaldehyde and other gases cannot be adsorbed, and the temperature in the reaction box is 25 ℃ at room temperature and the relative humidity is 50%. Formaldehyde concentration was monitored with an infrared acoustic gas detector. 100mg of the formaldehyde scavenger prepared in example 3 and comparative examples 1 to 4 was covered with a petri dish and placed in a reaction tank, and 20. Mu.L of a 38% aqueous formaldehyde solution was injected into the reaction tank and then sealed; when the formaldehyde concentration was 300ppm, the dish was opened to allow the formaldehyde scavenger to contact formaldehyde, starting the catalytic reaction. The formaldehyde scavenger prepared in example 3 of the present invention and comparative examples 1 to 4 were evaluated for performance by monitoring the concentration changes of formaldehyde and carbon dioxide in the test box over 1 hour.
The results of conversion of formaldehyde by the scavenger into carbon dioxide are shown in table 1, and it can be seen that comparative example 3 containing no platinum has a conversion rate of 0 to formaldehyde because formaldehyde molecules are adsorbed only on the scavenger surface and are not degraded, the formaldehyde concentration in the system is reduced, and no carbon dioxide is generated; however, the degradation of formaldehyde by several other formaldehyde scavengers is characterized by a reduced formaldehyde concentration and an increased carbon dioxide concentration, which indicates that formaldehyde is degraded to carbon dioxide; platinum has great promotion effect on formaldehyde degradation at room temperature of 25 ℃. The formaldehyde scavenger prepared in comparative example 4 has very weak formaldehyde degradation activity, which indicates that ceria has a significant effect on improving catalytic degradation, and it is possible that ceria provides oxygen holes to greatly promote formaldehyde catalytic reaction. As shown in table 1, example 3 exhibited higher catalytic performance with respect to comparative example 1 prepared without glycine addition and comparative example 2 prepared without activated diatomaceous earth, and the conversion rate to formaldehyde reached 96.2% in 1h. The remarkable improvement of the catalytic performance may be due to the fact that the diatomite surface activated in the formaldehyde scavenger prepared in example 3 is easy to generate a large amount of hydroxyl groups, which is helpful for the adsorption of formaldehyde molecules on the surface of the scavenger; glycine added in the preparation process has uniform dispersion effect on cerium ions, so that the agglomeration of cerium dioxide is reduced, the nitrogen doping after calcination is beneficial to the dispersion of platinum, and more active sites are improved; the presence of oxygen vacancies within the ceria greatly facilitates the degradation reaction. The effects generate good synergistic effect, improve the adsorption effect of formaldehyde molecules on the surface of the scavenger, further promote the catalytic degradation and effectively convert the formaldehyde molecules into carbon dioxide.
TABLE 1 conversion of formaldehyde scavengers
The formaldehyde scavenger prepared in example 3 of the present invention was subjected to a cyclic degradation test at room temperature of 25 c, a relative humidity of 50% and an initial formaldehyde concentration of 300 ppm. The results show that the catalytic activity is not obviously reduced compared with the first test after 5 continuous cycles, which shows that the performance is stable and the capability of effectively degrading formaldehyde for a long time is provided.
The formaldehyde scavenger prepared in inventive example 3 was subjected to formaldehyde degradation testing at a relative humidity of 5% to 85%, room temperature 25 ℃ and an initial formaldehyde concentration of 300ppm, as shown in fig. 1, where the conversion is standard for carbon dioxide formation. The result shows that when the relative humidity is 15-65%, the conversion rate of the scavenger to formaldehyde is above 85%; conversion was 68.2% at a relative humidity of 5%; the conversion was 72.6% at a relative humidity of 85%. These results show that the composition has good tolerance to common indoor conditions and does not generate toxic and harmful gases in daily use. The relatively high humidity is helpful for degrading formaldehyde, probably due to the fact that the relatively high humidity and the water vapor are helpful for forming hydroxyl groups on the surface, so that the adsorption of formaldehyde is enhanced, and the degrading capability of formaldehyde is enhanced; the proper amount of water vapor can inhibit the dynamic loss of surface hydroxyl groups in the formaldehyde oxidation reaction process, and is beneficial to the degradation reaction of formaldehyde; however, in the case of too high a relative humidity, excessive water molecules may form competitive adsorption with formaldehyde, occupy a part of adsorption sites, and even block mass transfer channels, thereby reducing catalytic activity.
Test example 2 formaldehyde scavenger catalyzed product analysis
The intermediate products of the degradation products of formaldehyde and the oxidation process were analyzed using an in situ infrared spectrometer. 100mg of the formaldehyde scavenger prepared in example 3 was placed in a reaction tank, and a mixed gas flow of formaldehyde and nitrogen was introduced and kept for 1 hour; then a stream of oxygen is introduced and maintained for 1h. Wherein the formaldehyde concentration in the initial mixed gas stream is 50ppm.
When the mixed gas flow is formaldehyde and nitrogen, the infrared peaks of formaldehyde molecules and formate species adsorbed in the process are gradually enhanced along with the increase of time; the stretching vibration peak of O-C-O of the dioxymethylene appears; while the infrared peak of the hydroxyl group gradually decreases. This indicates that formaldehyde molecules are converted to formate species and dioxymethylene, and that hydroxyl groups are consumed in the process. However, when oxygen is introduced, the infrared peaks of formaldehyde molecules and formate species are significantly reduced, the stretching vibration peak of O-C-O of dioxymethylene is gradually disappeared, and the results show that formate species are further converted, and formaldehyde molecules adsorbed on the surface are rapidly degraded.
Formaldehyde is separated into two stages of adsorption and degradation on the surface of the scavenger. Formaldehyde molecules are firstly bound on the surface of the scavenger through hydrogen bonds; subsequently, the active oxygen atoms adjacent to the ceria surface attack formaldehyde molecules to convert them to a dioxymethylene intermediate, and thus formate species; the formate species is further oxidized by the reactive oxygen species to carbonic acid, which then breaks down to carbon dioxide and water, which desorbs from the active sites on the scavenger surface, thereby regenerating the active sites. Hydroxyl adjacent to the oxygen vacancies of the ceria in the whole adsorption and degradation process can be regenerated through the reaction of surface adsorbed water and active oxygen species, and finally the recovery of the formaldehyde removal capability of the scavenger is realized.
These results demonstrate that the formaldehyde scavenger of example 3 of the present invention is effective in oxidizing formaldehyde to carbon dioxide without producing some toxic and deleterious intermediates.
Application example 1 use of formaldehyde scavenger for removal of free formaldehyde in a closed House
The formaldehyde scavenger filter cake prepared by the method of example 3 is prepared into a column shape with the diameter of 6mm and the height of 10mm by a granulator, and 10g of the column shape is separated and placed in a breathable non-woven fabric belt for standby; a newly decorated house with an area of 25m 2 The formaldehyde concentration of the sealed house is tested to be 0.61mg/m 3 The method comprises the steps of carrying out a first treatment on the surface of the Placing a total of 6 breathable non-woven fabrics bags with formaldehyde scavenger at multiple places in the room, and testing the formaldehyde concentration of the room after three days to be 0.04mg/m 3 The method comprises the steps of carrying out a first treatment on the surface of the The formaldehyde concentration in the room is continuously monitored, and the result shows that after the room is used for six months, the formaldehyde concentration in the room is tested to be 0.06mg/m under the same condition 3 Still in the national standard of 0.1mg/m 3 The following is given. These results demonstrate the potential of the formaldehyde scavenger prepared by the present invention to scavenge free formaldehyde in the room quickly and effectively for long periods of time.
The foregoing describes in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations can be made in accordance with the concepts of the invention by one of ordinary skill in the art without undue burden. Therefore, all technical solutions which can be obtained by logic analysis, reasoning or limited experiments based on the prior art by the person skilled in the art according to the inventive concept shall be within the scope of protection defined by the claims.
Claims (7)
1. The preparation method of the formaldehyde scavenger is characterized by comprising the following steps:
step 1: dispersing activated diatomite, a nitrogen source and a cerium source in water under stirring to form uniform suspension I;
step 2: dropwise adding the reaction solution into the suspension I which is continuously stirred, stirring for reaction, filtering to obtain a filter cake, washing and drying; calcining the dried filter cake, naturally cooling, crushing and sieving to obtain cerium oxide/activated diatomite composite powder;
step 3: uniformly dispersing the cerium dioxide/activated diatomite composite powder obtained in the step 2 in water under ultrasound to form a suspension II; adding chloroplatinic acid into the suspension which is continuously stirred, and continuously stirring; adding a reducing agent solution for reaction, and carrying out suction filtration, washing and drying to obtain a dry filter cake, namely the formaldehyde scavenger;
the weight ratio of the activated diatomite to the nitrogen source to the cerium source to the water in the step 1 is 100: (1-5): (10-20): 1000; the stirring speed is 300-500 r/min, and the stirring time is 1-3 h;
the weight ratio of the reaction solution to the water in the suspension in the step 2 is 1: (10-20); the dripping is carried out by putting into a constant pressure funnel at a speed of 10-30 g/min; the stirring speed of the suspension I is 300-500 r/min; the washing is carried out three times by ethanol and water respectively; the drying is to put the filter cake into a constant temperature oven to be dried for 3 to 5 hours at the temperature of between 60 and 100 ℃;
the ultrasonic power in the step 3 is 50-200W, the frequency is 20-130 KHz, the temperature is 20-40 ℃ and the time is 20-60 min; the stirring speed is 300-500 r/min; the weight ratio of the ceria/diatomite composite material to the water to the chloroplatinic acid to the reducing agent solution is 10:100: (0.1-0.5): (1-5); adding the reducer solution, and then continuing to react for 1-2 h at the stirring rate of 300-500 r/min; the washing is carried out three times by ethanol and water respectively; the drying is to put the materials into a constant temperature oven to be dried for 3 to 5 hours at the temperature of between 60 and 100 ℃;
the preparation method of the activated diatomite in the step 1 comprises the following steps: 10 to 20 parts of diatomite with 500 to 1000 meshes is placed in 100 to 300 parts of hydrochloric acid or nitric acid aqueous solution with 0.5mol/L to 3mol/L for soaking for 1 to 3 hours; washing with water until the pH value of the supernatant is 6.5-7.5, carrying out suction filtration, putting the filter cake into a constant temperature oven, drying at 60-100 ℃ for 3-5 hours, crushing the filter cake, sieving with a 500-1000 mesh sieve, and collecting the powder of the sieve to obtain activated diatomite;
the nitrogen source in the step 1 is one of urea, dicyandiamide and glycine;
the reaction solution in the step 2 is any one of sodium hydroxide, ammonia water, sodium carbonate and sodium bicarbonate, and the concentration is 0.6-2 mol/L.
2. The method for preparing formaldehyde scavenger according to claim 1, wherein the calcination temperature in step 2 is 500-700 ℃ and the calcination time is 3-5 hours; the sieving is carried out by sieving with a 500-1000 mesh sieve, and the powder passing through the sieve is collected.
3. The method for preparing formaldehyde scavenger according to claim 1, wherein the reducing agent solution in step 3 is an aqueous solution of ascorbic acid in an amount of 0.5 to 1 mol/L.
4. The method for preparing a formaldehyde scavenger according to claim 1, wherein the dried cake obtained in step 3 is crushed, passed through a 500-1000 mesh sieve, and the powder of the sieve is collected to obtain formaldehyde scavenger powder.
5. The method for preparing formaldehyde scavenger according to claim 1, wherein the dried filter cake obtained in step 3 is granulated into formaldehyde scavenger of different shapes by a granulator, and the shape is spherical with a diameter of 8-20 mm or columnar with a diameter of 6mm and a height of 10 mm.
6. A formaldehyde scavenger prepared by the method of any one of claims 1 to 5.
7. The formaldehyde scavenger application in scavenging chambers as defined in claim 6, wherein the breathable nonwoven bags containing formaldehyde scavenger are uniformly placed in a closed room with a room area of 20-30 m 2 The application amount of formaldehyde scavenger is 2-5 g/m 2 。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210446514.4A CN114797438B (en) | 2022-04-26 | 2022-04-26 | Formaldehyde scavenger, preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210446514.4A CN114797438B (en) | 2022-04-26 | 2022-04-26 | Formaldehyde scavenger, preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114797438A CN114797438A (en) | 2022-07-29 |
| CN114797438B true CN114797438B (en) | 2023-06-23 |
Family
ID=82508070
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210446514.4A Active CN114797438B (en) | 2022-04-26 | 2022-04-26 | Formaldehyde scavenger, preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114797438B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106582639A (en) * | 2017-01-09 | 2017-04-26 | 北京航空航天大学 | Catalyst capable of efficiently and synchronously catalyzing and oxidizing low-concentration gaseous phase formaldehyde and carbon monoxide and preparation method for catalyst |
| DE102017200833A1 (en) * | 2017-01-19 | 2018-07-19 | SinoHephaestus Solution GmbH | formaldehyde scavenger |
| CN110280252A (en) * | 2019-06-24 | 2019-09-27 | 检易（厦门）科技有限公司 | A kind of catalyst of degradation of formaldehyde and preparation method thereof |
| CN112588298A (en) * | 2020-12-29 | 2021-04-02 | 苏州美吉科环保科技有限公司 | Composite catalyst for air purification and preparation method and application thereof |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1867382A4 (en) * | 2005-03-29 | 2011-02-02 | Zen World Kk | Method for decomposition and removal of organic compound in air using platinum as main catalysis, method for formation of photocatalytic article and photocatalytic layer, and photocatalyst |
| CN102836712A (en) * | 2011-06-24 | 2012-12-26 | 上海牛翼新能源科技有限公司 | Catalyst for completely removing formaldehyde in indoor air at room temperature |
| CN105000586B (en) * | 2015-08-03 | 2017-02-15 | 攀钢集团攀枝花钢铁研究院有限公司 | One-step synthesizing method of high-dispersion and weak-agglomeration doped ceria |
| CN107930666B (en) * | 2017-11-10 | 2018-10-09 | 山东格蓝云天环境科技有限公司 | Nano cerium Mn oxide/absorbent charcoal composite material of Oxidation at room temperature formaldehyde and preparation method thereof |
| CN112299469B (en) * | 2020-09-22 | 2023-03-14 | 江汉大学 | Cerium dioxide and preparation method and application thereof |
| CN113145111B (en) * | 2020-11-26 | 2022-12-13 | 吉林大学 | Diatomite composite catalyst and preparation method and application thereof |
-
2022
- 2022-04-26 CN CN202210446514.4A patent/CN114797438B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106582639A (en) * | 2017-01-09 | 2017-04-26 | 北京航空航天大学 | Catalyst capable of efficiently and synchronously catalyzing and oxidizing low-concentration gaseous phase formaldehyde and carbon monoxide and preparation method for catalyst |
| DE102017200833A1 (en) * | 2017-01-19 | 2018-07-19 | SinoHephaestus Solution GmbH | formaldehyde scavenger |
| CN110280252A (en) * | 2019-06-24 | 2019-09-27 | 检易（厦门）科技有限公司 | A kind of catalyst of degradation of formaldehyde and preparation method thereof |
| CN112588298A (en) * | 2020-12-29 | 2021-04-02 | 苏州美吉科环保科技有限公司 | Composite catalyst for air purification and preparation method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114797438A (en) | 2022-07-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106334565B (en) | Air purification composite catalyst and preparation method thereof | |
| Zhang et al. | Controllable synthesis of WO3 with different crystalline phases and its applications on methylene blue removal from aqueous solution | |
| EP3421425A1 (en) | Solidified porous carbon material and production method thereof | |
| CN106955590A (en) | A kind of composite purifying agent in air purifier | |
| CN103691314A (en) | Deodorizing composition and application thereof | |
| CN106362584A (en) | Nano photo-catalyst air deodorant and preparation method of same | |
| CN108114711A (en) | A kind of catalyst of transition metal oxide and preparation method of catalytic eliminating ozone | |
| CN103949128B (en) | A kind of method and device purifying the flue gas containing dust | |
| CN105111711A (en) | Composition used for decomposition purification of formaldehyde, and preparation method and applications thereof | |
| CN106669604A (en) | Air purifying material capable of removing ammonia and secondhand smoke and preparation method thereof | |
| CN103506111A (en) | Method for preparing formaldehyde and ozone removal catalyst at room temperature | |
| CN105195168A (en) | Preparation of hollow hexahedron CuMn2O4 and application method of hollow hexahedron CuMn2O4 in technology of catalyzing ozone oxidation to remove pollution | |
| JP3799945B2 (en) | Room temperature purification catalyst and method of using the same | |
| CN108854432A (en) | A kind of active carbon removing formaldehyde/bacteria cellulose compounded mix and preparation method | |
| CN108993530A (en) | A kind of preparation method and application of hydrotalcite NiMnTi catalyst | |
| CN114797438B (en) | Formaldehyde scavenger, preparation method and application thereof | |
| CN107008055A (en) | A kind of air purifier environment-friendly high-efficiency material for core and preparation method thereof | |
| JP3221116B2 (en) | Catalyst for decomposition of nitrous oxide | |
| CN103752255A (en) | Material for purifying micromolecule poisonous gases as well as preparation method thereof | |
| CN111036071A (en) | Air purifying agent for removing formaldehyde and preparation method and application thereof | |
| CN111921375B (en) | Ag-MnO2/AC composite aldehyde-removing material, preparation method thereof, aldehyde-removing module and air purification equipment | |
| US20200001234A1 (en) | Apparatus for the treatment of air | |
| CN113019423B (en) | Catalyst for oxidizing ammonia gas by ozone, preparation method and application thereof | |
| CN103691300B (en) | A kind of preparation method of normal-temperature iron desulfurizer | |
| CN101972658A (en) | Carbonyl sulfide hydrolysis catalyst taking rare-earth hydrotalcite as precursor 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |