Preparation method of Mn-Ti oxide system low-temperature selective catalytic reduction (SCR) catalyst

Abstract

The invention discloses a preparation method of a Mn-Ti oxide system low-temperature selective catalytic reduction (SCR) catalyst. The preparation method comprises the following steps of: in a stirring condition, adding titanium tetrabutoxide in acrylic acid to uniformly mix, adding manganous nitrate and a solvent, and stirring a mixture to form a homogeneous phase solution, wherein a mol ratio of the titanium tetrabutoxide to the manganous nitrate ranges from 10: 1 to 10: 6, and a mol ratio of sum of the titanium tetrabutoxide and the manganous nitrate to the acrylic acid ranges from 1: 5 to 1: 1; deoxidizing by introducing nitrogen, and adding an initiator to polymerize, so as to obtain solid polyacrylate; and drying and carrying out pyrolysis on the solid polyacrylate, and then grinding to obtain Mn-Ti oxide powder. The preparation method provided by the invention has the advantages of easiness of control and convenience in implementation; metal ions in a prepared polymer precursor can be horizontally and uniformly mixed in an ion level; the grain size of the Mn-Ti oxide powder prepared by sintering the polymer precursor can reach a nanometer level and a narrow distribution range so that the Mn-Ti oxide system low-temperature SCR catalyst has a better application prospect in a low-temperature smoke SCR denitration reaction catalyst field.

Description

technical field

[0001] The invention belongs to the field of physical chemistry, and in particular relates to a preparation method of a Mn-Ti oxide system low-temperature selective catalytic reduction catalyst. Background technique

[0002] Stationary sources of nitrogen oxides (NO x ) treatment methods, the Selective Catalytic Reduction (SCR) method has become the mainstream technology for flue gas denitrification in thermal power plants because of its high efficiency and cost-effectiveness. However, the currently used selective catalytic reduction of NO x The V-W-Ti series catalysts require a higher reaction temperature, which is generally required to be controlled at 573~673K. In order to avoid reheating the flue gas, the SCR device must be placed before the desulfurization and dust removal, but in this way, the SO in the flue gas 2 and dust will cause different degrees of catalyst deactivation, which shortens the life of the catalyst; although the SCR device is placed...

Examples

Embodiment 1

[0018] A kind of preparation method of Mn-Ti oxide system low-temperature selective catalytic reduction catalyst, its specific steps are as follows:

[0019] (1) Under stirring conditions, add n-butyl titanate to acrylic acid (AA) and mix well; then add chemically pure manganese nitrate, wherein the molar ratio of n-butyl titanate, manganese nitrate and acrylic acid is 10:3 : 26; Then add ethanol, stir to form a homogeneous solution;

[0020] (2) Nitrogen is passed to remove the oxygen in the solution system, and then (NH 4 ) 2 S 2 o 8 The initiator, after mixing evenly, is placed in an oven to polymerize at a temperature of 80°C to obtain a solid polyacrylate;

[0021] (3) Dry the solid polyacrylate at 200° C. for 24 hours to obtain a polymer precursor.

[0022] (4) After the polymer precursor was pyrolyzed at 800 °C for 5 hours in an air atmosphere, it was ground to obtain the low-temperature selective catalytic reduction catalyst of the Mn-Ti oxide system, that is, the...

Embodiment 2

[0024] A kind of preparation method of Mn-Ti oxide system low-temperature selective catalytic reduction catalyst, its specific steps are as follows:

[0025] (1) Under stirring conditions, add n-butyl titanate to acrylic acid (AA) and mix well; then add chemically pure manganese nitrate, wherein the molar ratio of n-butyl titanate, manganese nitrate and acrylic acid is 5:2 : 21; Then add ethanol and water, stir to form a homogeneous solution;

[0026] (2) Nitrogen is passed to remove the oxygen in the solution system, and then (NH 4 ) 2 S 2 o 8 The initiator, after mixing evenly, is placed in an oven to polymerize at a temperature of 80°C to obtain a solid polyacrylate;

[0027] (3) Dry the solid polyacrylate at 220° C. for 24 hours to obtain a polymer precursor.

[0028] (4) The polymer precursor was pyrolyzed at 700°C for 6 hours in an air atmosphere, and then ground to obtain Mn-Ti oxide powder.

[0029] From the scanning electron micrograph of the final Mn-Ti oxide p...

Embodiment 3

[0031] A kind of preparation method of Mn-Ti oxide system low-temperature selective catalytic reduction catalyst, its specific steps are as follows:

[0032] (1) Under stirring conditions, add n-butyl titanate to acrylic acid (AA) and mix well; then add chemically pure manganese nitrate, wherein the molar ratio of n-butyl titanate, manganese nitrate and acrylic acid is 2:1 : 12; Then add Virahol and water, stir to form a homogeneous solution;

[0033] (2) Nitrogen is passed to remove the oxygen in the solution system, and then (NH 4 ) 2 S 2 o 8 The initiator, after mixing evenly, is placed in an oven to polymerize at a temperature of 80°C to obtain a solid polyacrylate;

[0034] (3) Dry the solid polyacrylate at 240° C. for 36 hours to obtain a polymer precursor.

[0035] (4) The polymer precursor was pyrolyzed at 600°C for 8 hours in an air atmosphere and ground to obtain Mn-Ti oxide powder.

technical field

[0001] The invention belongs to the field of physical chemistry, and in particular relates to a preparation method of a Mn-Ti oxide system low-temperature selective catalytic reduction catalyst. Background technique

[0002] Stationary sources of nitrogen oxides (NO x ) treatment methods, the Selective Catalytic Reduction (SCR) method has become the mainstream technology for flue gas denitrification in thermal power plants because of its high efficiency and cost-effectiveness. However, the currently used selective catalytic reduction of NO x The V-W-Ti series catalysts require a higher reaction temperature, which is generally required to be controlled at 573~673K. In order to avoid reheating the flue gas, the SCR device must be placed before the desulfurization and dust removal, but in this way, the SO in the flue gas 2 and dust will cause different degrees of catalyst deactivation, which shortens the life of the catalyst; although the SCR device is placed...

Examples

Embodiment 1

[0018] A kind of preparation method of Mn-Ti oxide system low-temperature selective catalytic reduction catalyst, its specific steps are as follows:

[0019] (1) Under stirring conditions, add n-butyl titanate to acrylic acid (AA) and mix well; then add chemically pure manganese nitrate, wherein the molar ratio of n-butyl titanate, manganese nitrate and acrylic acid is 10:3 : 26; Then add ethanol, stir to form a homogeneous solution;

[0020] (2) Nitrogen is passed to remove the oxygen in the solution system, and then (NH 4 ) 2 S 2 o 8 The initiator, after mixing evenly, is placed in an oven to polymerize at a temperature of 80°C to obtain a solid polyacrylate;

[0021] (3) Dry the solid polyacrylate at 200° C. for 24 hours to obtain a polymer precursor.

[0022] (4) After the polymer precursor was pyrolyzed at 800 °C for 5 hours in an air atmosphere, it was ground to obtain the low-temperature selective catalytic reduction catalyst of the Mn-Ti oxide system, that is, the...

Embodiment 2

[0024] A kind of preparation method of Mn-Ti oxide system low-temperature selective catalytic reduction catalyst, its specific steps are as follows:

[0025] (1) Under stirring conditions, add n-butyl titanate to acrylic acid (AA) and mix well; then add chemically pure manganese nitrate, wherein the molar ratio of n-butyl titanate, manganese nitrate and acrylic acid is 5:2 : 21; Then add ethanol and water, stir to form a homogeneous solution;

[0026] (2) Nitrogen is passed to remove the oxygen in the solution system, and then (NH 4 ) 2 S 2 o 8 The initiator, after mixing evenly, is placed in an oven to polymerize at a temperature of 80°C to obtain a solid polyacrylate;

[0027] (3) Dry the solid polyacrylate at 220° C. for 24 hours to obtain a polymer precursor.

[0028] (4) The polymer precursor was pyrolyzed at 700°C for 6 hours in an air atmosphere, and then ground to obtain Mn-Ti oxide powder.

[0029] From the scanning electron micrograph of the final Mn-Ti oxide p...

Embodiment 3

[0031] A kind of preparation method of Mn-Ti oxide system low-temperature selective catalytic reduction catalyst, its specific steps are as follows:

[0032] (1) Under stirring conditions, add n-butyl titanate to acrylic acid (AA) and mix well; then add chemically pure manganese nitrate, wherein the molar ratio of n-butyl titanate, manganese nitrate and acrylic acid is 2:1 : 12; Then add Virahol and water, stir to form a homogeneous solution;

[0033] (2) Nitrogen is passed to remove the oxygen in the solution system, and then (NH 4 ) 2 S 2 o 8 The initiator, after mixing evenly, is placed in an oven to polymerize at a temperature of 80°C to obtain a solid polyacrylate;

[0034] (3) Dry the solid polyacrylate at 240° C. for 36 hours to obtain a polymer precursor.

[0035] (4) The polymer precursor was pyrolyzed at 600°C for 8 hours in an air atmosphere and ground to obtain Mn-Ti oxide powder.

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