Ammonia oxidation catalyst for internal combustion engine tail gas purification system and preparation method thereof

Abstract

The present invention is an ammonia oxidation catalyst for an internal combustion engine tail gas purification system, comprising a carrier and a loaded active component, characterized in that the active component is copper ions and noble metal Pt, and the loading of the copper ions is 1- 5%, the loading of the noble metal Pt is 0.1-1%, the loading is the percentage of the mass of the active component in the mass of the ammonia-oxygen catalyst, and the carrier is a self-made SSZ-13 molecular sieve. In the present invention, copper ions and precious metal Pt are loaded on self-made SSZ-13 molecular sieve, and the adsorption capacity of the molecular sieve is enhanced by improving the silicon-aluminum ratio, which can improve the dispersion of noble metal Pt in the molecular sieve, improve the catalytic activity of the catalyst, and have high catalyst selectivity and strong catalytic ability. .

Description

technical field

[0001] The invention relates to the field of catalyst preparation, in particular to an ammonia oxidation catalyst used in an internal combustion engine tail gas purification system, and a preparation method thereof. Background technique

[0002] With the acceleration of urbanization, the number of motor vehicles in my country is increasing, and diesel vehicles are widely used due to their high work efficiency and good fuel economy, but the pollutants emitted by diesel vehicles include SO X , NO X , CO X Air pollution is an important source of air pollution. Under different working conditions, such as cold start, idling, driving on flat roads, driving on slopes, etc., internal combustion engines will produce exhaust emissions with different temperatures, different contents, and different compositions. More complex, more difficult to govern and control.

[0003] Selective catalytic reduction technology (SCR) is a treatment process for NOx in diesel vehicle ...

Examples

Embodiment 1

[0046] The preparation of embodiment 1 copper-based and platinum-based bimetallic catalyst

[0047] (1) Weigh 66 grams of ammonium sulfate to prepare 2.0 L of 0.5 mol / L solution. Weigh 200 grams of the self-made SSZ-13 molecular sieve required by the present invention, add it to the ammonium sulfate solution, put it in a water bath at 80 degrees Celsius, let it stand overnight at a constant temperature, then pour out the supernatant, and wash and dry the solid with hot water. In the muffle furnace, the temperature was raised to 540 degrees Celsius at a rate of 1 degree Celsius per minute, kept for 2 hours, and cooled to obtain a hydrogen-type SSZ-13 molecular sieve.

[0048] (2) Weigh 5 grams of the SSZ-13 molecular sieve obtained in step (1), add deionized water dropwise until the molecular sieve is wetted, the measured water absorption is 3 grams, and the calculated water absorption is 0.6.

[0049] (3) Calculate the water absorption of 9.4 grams of SSZ-13 molecular sieves ...

Embodiment 2

[0051] The preparation of embodiment 2 copper-based and platinum-based bimetallic catalysts

[0052] This implementation only describes the differences from Embodiment 1.

[0053] Calculate the water absorption of 9.46 grams of SSZ-13 molecular sieve according to the water absorption of step (2) SSZ-13 molecular sieve of step embodiment 1, 1.698 grams of copper nitrate and 0.9 gram of platinum nitrate are dissolved in the above-mentioned water absorption together, it is dropwise Add to 9.62 grams of SSZ-13 molecular sieve obtained in step (1), fully stir and mix evenly, after drying at 80 degrees Celsius, place in a muffle furnace, heat up to 540 degrees Celsius at a rate of 1 degree Celsius per minute, and roast at a constant temperature After 2 hours, cool to room temperature to obtain copper-supported and Pt-supported bimetallic ammoxidation catalyst samples, labeled as catalyst A2. The copper loading weight ratio of the catalyst was 4.5%, and the Pt loading weight ratio w...

Embodiment 3

[0054] The preparation of embodiment 3 copper-based and platinum-based bimetallic catalysts

[0055] This implementation only describes the differences from Embodiment 1.

[0056] Calculate the water absorption of 9.55 grams of SSZ-13 molecular sieve according to the water absorption of step (2) SSZ-13 molecular sieve of step embodiment 1, 1.51 grams of copper nitrate and 0.5 gram of platinum nitrate are dissolved in the above-mentioned water absorption together, it is dropwise Add to 9.65 grams of SSZ-13 molecular sieve obtained in step (1), fully stir and mix evenly, after drying at 80 degrees Celsius, place in a muffle furnace, heat up to 540 degrees Celsius at a rate of 1 degree Celsius per minute, and roast at a constant temperature After cooling to room temperature for 2 hours, a copper-supported and Pt-supported bimetallic ammoxidation catalyst sample was obtained, labeled as catalyst A3. The copper loading weight ratio of the catalyst was 4%, and the Pt loading weight...

technical field

[0001] The invention relates to the field of catalyst preparation, in particular to an ammonia oxidation catalyst used in an internal combustion engine tail gas purification system, and a preparation method thereof. Background technique

[0002] With the acceleration of urbanization, the number of motor vehicles in my country is increasing, and diesel vehicles are widely used due to their high work efficiency and good fuel economy, but the pollutants emitted by diesel vehicles include SO X , NO X , CO X Air pollution is an important source of air pollution. Under different working conditions, such as cold start, idling, driving on flat roads, driving on slopes, etc., internal combustion engines will produce exhaust emissions with different temperatures, different contents, and different compositions. More complex, more difficult to govern and control.

[0003] Selective catalytic reduction technology (SCR) is a treatment process for NOx in diesel vehicle ...

Examples

Embodiment 1

[0046] The preparation of embodiment 1 copper-based and platinum-based bimetallic catalyst

[0047] (1) Weigh 66 grams of ammonium sulfate to prepare 2.0 L of 0.5 mol / L solution. Weigh 200 grams of the self-made SSZ-13 molecular sieve required by the present invention, add it to the ammonium sulfate solution, put it in a water bath at 80 degrees Celsius, let it stand overnight at a constant temperature, then pour out the supernatant, and wash and dry the solid with hot water. In the muffle furnace, the temperature was raised to 540 degrees Celsius at a rate of 1 degree Celsius per minute, kept for 2 hours, and cooled to obtain a hydrogen-type SSZ-13 molecular sieve.

[0048] (2) Weigh 5 grams of the SSZ-13 molecular sieve obtained in step (1), add deionized water dropwise until the molecular sieve is wetted, the measured water absorption is 3 grams, and the calculated water absorption is 0.6.

[0049] (3) Calculate the water absorption of 9.4 grams of SSZ-13 molecular sieves ...

Embodiment 2

[0051] The preparation of embodiment 2 copper-based and platinum-based bimetallic catalysts

[0052] This implementation only describes the differences from Embodiment 1.

[0053] Calculate the water absorption of 9.46 grams of SSZ-13 molecular sieve according to the water absorption of step (2) SSZ-13 molecular sieve of step embodiment 1, 1.698 grams of copper nitrate and 0.9 gram of platinum nitrate are dissolved in the above-mentioned water absorption together, it is dropwise Add to 9.62 grams of SSZ-13 molecular sieve obtained in step (1), fully stir and mix evenly, after drying at 80 degrees Celsius, place in a muffle furnace, heat up to 540 degrees Celsius at a rate of 1 degree Celsius per minute, and roast at a constant temperature After 2 hours, cool to room temperature to obtain copper-supported and Pt-supported bimetallic ammoxidation catalyst samples, labeled as catalyst A2. The copper loading weight ratio of the catalyst was 4.5%, and the Pt loading weight ratio w...

Embodiment 3

[0054] The preparation of embodiment 3 copper-based and platinum-based bimetallic catalysts

[0055] This implementation only describes the differences from Embodiment 1.

[0056] Calculate the water absorption of 9.55 grams of SSZ-13 molecular sieve according to the water absorption of step (2) SSZ-13 molecular sieve of step embodiment 1, 1.51 grams of copper nitrate and 0.5 gram of platinum nitrate are dissolved in the above-mentioned water absorption together, it is dropwise Add to 9.65 grams of SSZ-13 molecular sieve obtained in step (1), fully stir and mix evenly, after drying at 80 degrees Celsius, place in a muffle furnace, heat up to 540 degrees Celsius at a rate of 1 degree Celsius per minute, and roast at a constant temperature After cooling to room temperature for 2 hours, a copper-supported and Pt-supported bimetallic ammoxidation catalyst sample was obtained, labeled as catalyst A3. The copper loading weight ratio of the catalyst was 4%, and the Pt loading weight...

Images