CN-121972214-A - Multi-effect catalyst for ammonia fuel engine and preparation method and application thereof

Abstract

The invention discloses a multi-effect catalyst for an ammonia fuel engine and a preparation method and application thereof, wherein the multi-effect catalyst is formed by coating a first coating and a second coating on a carrier, the first coating is a molecular sieve catalytic coating with high NH 3 leakage, the coating adopts one molecular sieve or a mixture of more than two molecular sieves of M-BEA, M-FAU, M-MFI and M-CHA, wherein M represents one or more of Mn, ce and Cu, the second coating is a high-efficiency N 2 O removal coating, and the coating adopts Fe-X material, wherein X is one molecular sieve or a mixture of more than two molecular sieves of FER, BEA, AFX. The catalyst directly uses NH 3 discharged by an ammonia fuel engine as a reducing agent to cooperatively catalyze and reduce N 2 O, NOx, thereby realizing pollution control by pollution and meeting the near-zero discharge requirement of new fuel power.

Inventors

• MA JIANGLI
• LI SHUNHONG
• YAN JIE
• YU FEI
• CHANG SHIYING
• YANG DONGXIA
• LAI HUILONG
• LIU WUMING
• Luo Hongyao
• WANG XIANKUN

Assignees

• 昆明贵研催化剂有限责任公司

Dates

Publication Date

20260505

Application Date

20260316

Claims (5)

1. 1. A multi-effect catalyst for an ammonia fuel engine is characterized in that a first coating and a second coating are coated on a carrier, the first coating is a molecular sieve catalytic coating with high NH 3 leakage, the coating adopts one molecular sieve or a mixture of more than two molecular sieves of M-BEA, M-FAU, M-MFI and M-CHA, M represents active metal and is one or more of Mn, ce and Cu, the second coating is a high-efficiency N 2 O removal coating, the coating adopts Fe-X material, and X is one molecular sieve or a mixture of more than two molecular sieves of FER, BEA, AFX.
2. 2. The multi-effect catalyst for ammonia-fueled engine according to claim 1, wherein the M-BEA molecular sieve, M-FAU molecular sieve, M-MFI molecular sieve, M-CHA molecular sieve have a SiO 2 /Al 2 O 3 molar ratio of 20 to 30, a M/Al molar ratio of 0.08 to 0.18, and the active metal is present in an ionic state on the molecular sieve framework.
3. 3. The multi-effect catalyst for ammonia-fueled engine according to claim 1 or 2, wherein the Fe-X material has a SiO 2 /Al 2 O 3 molar ratio of 18 to 25, a Fe/Al molar ratio of 0.18 to 0.23, and Fe is present on the molecular sieve framework in the form of Fe 2+ .
4. 4. A method for preparing a multi-effect catalyst for an ammonia-fueled engine according to claim 1, 2 or 3, characterized by comprising the steps of: Preparing a first coating slurry of a molecular sieve catalytic material, coating the first coating slurry on the air inlet end of a carrier according to the load of 90-120g/L, preparing a second coating slurry of an Fe-X material, and coating the second coating slurry on the air outlet end of the carrier according to the load of 90-150g/L, wherein the coating height ratio of the first coating to the second coating is 1:1-1:4; or coating the first coating slurry on the bottom layer of the carrier along the air inlet direction of the carrier, coating the second coating slurry on the outer layer of the carrier, wherein the coating height ratio of the first coating to the second coating is 1:1-1:4; Placing the coated carrier in a tubular furnace, introducing N 2 or H 2 or He into the furnace, and calcining for 1-3H at the room temperature of 450-525 ℃ to obtain the multi-effect catalyst.
5. 5. The multi-effect catalyst for an ammonia fuel engine of any one of claims 1-3 is applied to exhaust emission of an ammonia fuel engine, an ammonia-hydrogen fusion engine or an ammonia diesel engine, and is used for controlling NH 3 、NOx、N 2 O.

Description

Multi-effect catalyst for ammonia fuel engine and preparation method and application thereof Technical Field The invention belongs to the technical field of catalysts for engines, and particularly relates to a multi-effect catalyst for an ammonia fuel engine, and a preparation method and application thereof. Background NH 3 is a potential zero-carbon fuel, and is widely focused on the technical route of internal combustion engine alternative fuels because of the carbon-free molecular structure, mature synthetic storage and transportation system and higher energy density. However, the large-scale application of ammonia fueled engines fueled by NH 3 is faced with serious exhaust aftertreatment technology challenges, with emission characteristics that are substantially different from those of conventional hydrocarbon fueled engines. Firstly, ammonia has higher minimum ignition energy and narrower flammable range, so that incomplete combustion is easy to occur in the in-cylinder combustion process, serious escape of a large amount of unburned ammonia (> 8000 ppm) is caused, environmental pollution is caused, ammonia leakage of a downstream Selective Catalytic Reduction (SCR) system is more likely to be excessive, secondly, an intermediate product of ammonia combustion is complex, a large amount of strong greenhouse gas N 2 O (> 100 ppm) can be generated particularly under a low-temperature working condition, the global warming potential value of the intermediate product can reach approximately 300 times of that of carbon dioxide, and meanwhile, because NH 3 directly contains nitrogen atoms, the intermediate product is influenced by a combustion mode of high exhaust temperature of an engine, and high-concentration NOx (> 5000 ppm) is extremely easy to generate. the emission concentration of these three major pollutants is significantly above the conventional diesel engine level (up to 2-5 times), resulting in a multiple increase in the load and complexity of the aftertreatment technology. The prior post-treatment technology system is mainly constructed based on a diesel engine or gasoline engine platform with national standard, and the core of the post-treatment technology system is an Oxidation Catalyst (OC), a particulate matter catcher (DPF), NH 3 selective catalytic reduction (NH 3 -SCR) and the like, these techniques have significant drawbacks for the synergistic purification of specific pollutants of ammonia-fueled engines, particularly NH 3 and N 2 O. Although the traditional SCR catalyst realizes the high-efficiency conversion of low-concentration (2000 ppm) NOx, when the concentration of NOx is increased to more than 4000ppm, the ideal reaction path of the SCR catalyst is damaged by high-concentration NOx, the ideal reaction path is changed from the high-efficiency main reaction to low-speed or harmful side reaction, the conversion efficiency of NOx is greatly attenuated, the low emission requirement of an ammonia fuel engine is difficult to meet, the thermal decomposition of N 2 O needs high temperature (T 50 >600 ℃), the conversion efficiency of N 2 O below 400 ℃ is lower than 10%, the large emission of N 2 O is caused, more importantly, the synchronous high-efficiency removal of the NOx is difficult to realize by a single catalyst, and the method for integrating NH 3 inhibition is not available at present Therefore, development of a novel multi-effect post-treatment catalyst aiming at special emission of an ammonia fuel engine is needed, and the catalyst needs to realize high-efficiency oxidation of NH 3, low-temperature catalytic decomposition of N 2 O and high-efficiency oxidation of N 2 O in a wide temperature window, And a multifunctional active center for NOx selective reduction, and exhibits excellent stability to break through the technical bottleneck of ammonia internal combustion engine cleanliness, providing a core solution for commercial application of zero-carbon fuel engines. Disclosure of Invention The invention aims to solve the problems in the prior art and provide a multi-effect catalyst for an ammonia fuel engine, which can simultaneously remove N 2O、NOx、NH3, and a preparation method and application thereof. The technical scheme adopted by the invention is as follows: a multi-effect catalyst for ammonia fuel engine is prepared as coating the first coating layer on carrier and the second coating layer on carrier, using molecular sieve catalytic coating layer with high NH 3 leakage, using one molecular sieve or mixture of two or more molecular sieves of M-BEA, M-FAU, M-MFI and M-CHA, using M to represent active metal as one or more of Mn, ce and Cu for catalytic reduction of NOx by NH 3 in exhaust gas, using Fe-X material as high-efficiency N 2 O removing coating layer, using one molecular sieve or mixture of two or more molecular sieves of FER, BEA, AFX as X for catalytic reduction of N 2 O and NOx by NH 3 leakage of first coating layer. The catalyst directly uses NH 3