Transition metal oxide composite catalyst, preparation method thereof and application of catalyst

Abstract

The invention provides a transition metal oxide composite catalyst, a preparation method thereof and an application of the catalyst. The catalyst comprises a transition metal oxide active component and a carrier, and the transition metal oxide comprises an iron and vanadium composite oxide. According to the catalyst, iron is led in a vanadium and titanium denitration catalyst, the operating temperature of the catalyst can be widened to 200-450 DEG C by the aid of interaction between the iron and the vanadium and combination between an active site and an acid site of the carrier, denitration efficiency is improved, the conversion rate of NOx within the temperature range reaches 80% or more, generating selectivity of N2 is good, stability, sulfur resistance and water resistance of the catalyst can be enhanced, and the catalyst is low in cost, simple and easy in preparation process and wide in application range.

Description

technical field

[0001] The invention belongs to the technical field of catalysts, and relates to a transition metal composite catalyst and its preparation method and application, in particular to a transition metal composite catalyst, its preparation method and its application in the field of flue gas denitrification. Background technique

[0002] Nitrogen oxides (NO x ) as a common gaseous pollutant is an important cause of photochemical smog. It has become an important air pollutant second only to inhalable particulate matter and sulfur dioxide. NO emissions from stationary sources represented by gas and mobile sources represented by diesel vehicle exhaust x accounts for about 60% of emissions. Therefore, many flue gas denitrification technologies have developed rapidly in recent years, and selective catalytic reduction of ammonia (NH 3 -SCR) technology has received extensive attention due to its advantages of maturity, reliability, high efficiency, and good selectivity...

Examples

preparation example Construction

[0055] The preparation method of described catalyst comprises:

[0056] (1) Add slow-release precipitant to the mixed solution of iron source, vanadium source and titanium source, and react to obtain solid precipitate;

[0057] (2) Calcining the solid precipitate obtained in step (1) to obtain the transition metal oxide composite catalyst.

Embodiment 1

[0060] This example provides a transition metal oxide composite catalyst and its preparation method. The catalyst includes an iron-vanadium composite oxide active component and a titanium dioxide carrier, wherein the molar ratio of iron, vanadium and titanium is 0.1:0.1:1.

[0061] The preparation method of described catalyst comprises:

[0062] (1) Prepare a solution with ammonium metavanadate as a vanadium source, add oxalic acid to promote dissolution, then add iron nitrate and titanium sulfate to the ammonium metavanadate solution, stir and dissolve to obtain a mixed solution, wherein ammonium metavanadate, iron nitrate, sulfuric acid The molar ratio of titanium is 0.1:0.1:1. Add urea to the mixed solution. The molar number of urea is 10 times the total molar number of ammonium metavanadate, ferric nitrate and titanium sulfate. React for 12 hours in a water bath at 90°C, filter Separated to obtain a solid precipitate;

[0063] (2) Dry the solid precipitate obtained in ste...

Embodiment 2

[0071] This example provides a transition metal oxide composite catalyst and its preparation method. The catalyst includes an iron-vanadium composite oxide active component and a titanium dioxide carrier, wherein the molar ratio of iron, vanadium and titanium is 0.05:0.05:1.

[0072] The preparation method of described catalyst comprises:

[0073] (1) Take vanadyl oxalate as the vanadium source preparation solution, add oxalic acid to promote dissolution, then add ferric chloride and titanium tetrachloride to the vanadyl oxalate solution, stir and dissolve to obtain a mixed solution, wherein vanadyl oxalate, ferric chloride, The molar ratio of titanium tetrachloride is 0.05:0.05:1. Add ammonium carbonate to the mixed solution. The molar number of ammonium carbonate is 15 times the total molar number of vanadyl oxalate, ferric chloride and titanium tetrachloride. Reacted for 16 hours under water bath conditions, separated by filtration to obtain a solid precipitate;

[0074] (...

technical field

[0001] The invention belongs to the technical field of catalysts, and relates to a transition metal composite catalyst and its preparation method and application, in particular to a transition metal composite catalyst, its preparation method and its application in the field of flue gas denitrification. Background technique

[0002] Nitrogen oxides (NO x ) as a common gaseous pollutant is an important cause of photochemical smog. It has become an important air pollutant second only to inhalable particulate matter and sulfur dioxide. NO emissions from stationary sources represented by gas and mobile sources represented by diesel vehicle exhaust x accounts for about 60% of emissions. Therefore, many flue gas denitrification technologies have developed rapidly in recent years, and selective catalytic reduction of ammonia (NH 3 -SCR) technology has received extensive attention due to its advantages of maturity, reliability, high efficiency, and good selectivity...

Examples

preparation example Construction

[0055] The preparation method of described catalyst comprises:

[0056] (1) Add slow-release precipitant to the mixed solution of iron source, vanadium source and titanium source, and react to obtain solid precipitate;

[0057] (2) Calcining the solid precipitate obtained in step (1) to obtain the transition metal oxide composite catalyst.

Embodiment 1

[0060] This example provides a transition metal oxide composite catalyst and its preparation method. The catalyst includes an iron-vanadium composite oxide active component and a titanium dioxide carrier, wherein the molar ratio of iron, vanadium and titanium is 0.1:0.1:1.

[0061] The preparation method of described catalyst comprises:

[0062] (1) Prepare a solution with ammonium metavanadate as a vanadium source, add oxalic acid to promote dissolution, then add iron nitrate and titanium sulfate to the ammonium metavanadate solution, stir and dissolve to obtain a mixed solution, wherein ammonium metavanadate, iron nitrate, sulfuric acid The molar ratio of titanium is 0.1:0.1:1. Add urea to the mixed solution. The molar number of urea is 10 times the total molar number of ammonium metavanadate, ferric nitrate and titanium sulfate. React for 12 hours in a water bath at 90°C, filter Separated to obtain a solid precipitate;

[0063] (2) Dry the solid precipitate obtained in ste...

Embodiment 2

[0071] This example provides a transition metal oxide composite catalyst and its preparation method. The catalyst includes an iron-vanadium composite oxide active component and a titanium dioxide carrier, wherein the molar ratio of iron, vanadium and titanium is 0.05:0.05:1.

[0072] The preparation method of described catalyst comprises:

[0073] (1) Take vanadyl oxalate as the vanadium source preparation solution, add oxalic acid to promote dissolution, then add ferric chloride and titanium tetrachloride to the vanadyl oxalate solution, stir and dissolve to obtain a mixed solution, wherein vanadyl oxalate, ferric chloride, The molar ratio of titanium tetrachloride is 0.05:0.05:1. Add ammonium carbonate to the mixed solution. The molar number of ammonium carbonate is 15 times the total molar number of vanadyl oxalate, ferric chloride and titanium tetrachloride. Reacted for 16 hours under water bath conditions, separated by filtration to obtain a solid precipitate;

[0074] (...

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