Manganese-doped maghemite catalyst used for thermal catalytic oxidation of formaldehyde, and preparation method thereof

A technology of maghemite and manganese doping, which is applied in the field of manganese-doped maghemite catalyst and its preparation, can solve the problems of low catalytic activity, high price, easy loss, etc., and achieve high catalytic activity and thermal stability Good, low ignition temperature effect

Active Publication Date: 2015-11-04
GUANGZHOU INST OF GEOCHEMISTRY - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The initial catalytic activity of noble metal catalysts is good, but there are disadvantages such as high price, easy poisoning, easy loss, etc.
Transition metal catalysts have the advantages of lo

Method used

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  • Manganese-doped maghemite catalyst used for thermal catalytic oxidation of formaldehyde, and preparation method thereof
  • Manganese-doped maghemite catalyst used for thermal catalytic oxidation of formaldehyde, and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] 1. Weigh 27.8g FeSO 4 ·7H 2 O (0.1mol), 54.1g FeCl 3 ·6H 2 O (0.2mol) was added into 400mL ultrapure water (x=0), and under the protection of argon, it was completely dissolved to obtain 2+ , Fe 3+ solution of metal ions.

[0019] 2. Under the protection of argon, add the metal ion solution dropwise into 210mL of 4mol / L NaOH solution, and keep stirring the solution to form a black precipitate until the precipitation is complete; then crystallize the black precipitate at a constant temperature of 90°C for 24 hours .

[0020] 3. Centrifuge the black precipitate, collect the black precipitate, wash 3 times with ultrapure water, use a freeze dryer, freeze-dry in vacuum at a temperature of -40~-50°C for 24 hours, and obtain granular manganese-doped Magnetite precursor.

[0021] 4. Grading and screening Take the 35-60 mesh manganese-doped magnetite precursor, put it in a muffle furnace and roast it at 450° C. for 4 hours to obtain a composite sample 1 .

[0022] 5. Id...

Embodiment 2

[0024] 1. Weigh 22.2g FeSO 4 ·7H 2 O (0.08mol), 54.1g FeCl 3 ·6H 2 O (0.2mol), 3.4g MnSO 4 ·H 2 O (0.02mol) was added into 400mL ultrapure water (x=0.2), and under the protection of argon, it was completely dissolved to obtain 2+ , Fe 3+ , Mn 2+ solution of metal ions.

[0025] 2. Under the protection of argon, add the metal ion solution dropwise into 210mL of 4mol / L NaOH solution, and keep stirring the solution to form a black precipitate until the precipitation is complete; then crystallize the black precipitate at a constant temperature of 90°C for 24 hours .

[0026] 3. Centrifuge the black precipitate, collect the black precipitate, wash 3 times with ultrapure water, use a freeze dryer, and freeze-dry at a temperature of -40 to -50°C for 24 hours in a vacuum. After drying, granular manganese-doped magnetic Iron ore precursors.

[0027] 4. Grading and screening Take the 35-60 mesh manganese-doped magnetite precursor, put it in a muffle furnace and roast it at 450...

Embodiment 3

[0030] 1. Weigh 13.9g FeSO 4 ·7H 2 O (0.05mol), 54.1g FeCl 3 ·6H 2 O (0.2mol), 8.5g MnSO 4 ·H 2 O (0.05mol) was added into 400mL ultrapure water (x=0.5), and under the protection of argon, it was completely dissolved to obtain 2+ , Fe 3+ , Mn 2+ solution of metal ions.

[0031] 2. Under the protection of argon, add the metal ion solution dropwise into 210mL of 4mol / L NaOH solution, and keep stirring the solution to form a black precipitate until the precipitation is complete, and then crystallize the black precipitate at a constant temperature of 100°C for 24 hours .

[0032] 3. Centrifuge the black precipitate, collect the black precipitate, wash 3 times with ultrapure water, use a freeze dryer, and freeze-dry at a temperature of -40 to -50°C for 24 hours in a vacuum. After drying, granular manganese-doped magnetic Iron ore precursors.

[0033]4. Grading and screening Take the 35-60 mesh manganese-doped magnetite precursor, put it in a muffle furnace and roast it at...

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Abstract

The invention discloses a manganese-doped maghemite catalyst used for thermal catalytic oxidation of formaldehyde, and a preparation method thereof. According to the preparation method, a ferric salt and a manganese salt are taken as the main raw materials; a manganese-doped maghemite precursor is synthesized via sodium hydroxide coprecipitation; and the manganese-doped maghemite precursor is subjected to washing, freeze drying, screening, and roasting oxidation so as to obtain the manganese-doped maghemite catalyst used for thermal catalytic oxidation of formaldehyde. The manganese-doped maghemite catalyst is granular, possesses spinel structures, and weak magnetism. The manganese-doped maghemite catalyst can be used for effective thermal catalytic oxidation of high-concentration formaldehyde, and can be used for removing high-concentration formaldehyde (>1000mL/m3) at 300 DEG C; formaldehyde removing rate is 90% or higher; catalytic activity is high; initiation temperature is low; thermal stability is excellent; separation and recovery are convenient; no secondary pollution is caused; cost is low; and the manganese-doped maghemite catalyst is suitable for purifying treatment of high concentration formaldehyde in industrial exhaust gas.

Description

technical field [0001] The invention belongs to the technical field of formaldehyde oxidation treatment, and in particular relates to a manganese-doped maghemite catalyst for thermocatalytic oxidation of formaldehyde and a preparation method thereof. Background technique [0002] With the rapid development of my country's industry, the problem of air pollution is becoming more and more serious, and the research and development of industrial waste gas treatment technology has received extensive attention. Formaldehyde (HCHO) is one of the important raw materials in the field of chemical production. The industrial waste gas in many production fields such as building materials, textile printing and dyeing contains a relatively high concentration of formaldehyde. Formaldehyde is a typical volatile organic compound (VOCs), which has acute toxicity, carcinogenicity, mutagenicity and other hazards, and its direct emission will cause serious harm to human health and the environment....

Claims

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Application Information

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IPC IPC(8): B01J23/889B01D53/86B01D53/72
Inventor 梁晓亮刘鹏何宏平谭伟谭服鼎
Owner GUANGZHOU INST OF GEOCHEMISTRY - CHINESE ACAD OF SCI
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