11results about How to "High hydrothermal stability" patented technology

The application discloses a preparation method of Y molecular sieve, which comprises the following steps: mixing a silicon source, an aluminum source, an alkali source and a template agent to form a molecular sieve mother liquor, and performing crystallization, filtration, washing, drying and calcination to obtain the Y molecular sieve, wherein the template agent is polydialkyldimethylammonium chloride. The Y molecular sieve synthesis method is simple, the template agent used is environment-friendly and low in price, and the Y molecular sieve prepared by the method has the advantages of high silicon-aluminum ratio, large specific surface area, high crystallinity and good mass transfer effect.

This disclosure relates to a modified small-crystal Y molecular sieve, its preparation method, and its application. The preparation method includes the following steps: (1) mixing small-crystal NaY molecular sieve, a phosphorus source, and water in a weight ratio of NaY:P2O5:water = 1:(0.01~0.15):(8~10), and performing a first exchange on the resulting material below 100°C to obtain a phosphorus-containing small-crystal Y molecular sieve; (2) mixing the phosphorus-containing small-crystal Y molecular sieve with a rare earth source solution in a weight ratio of NaY:RE2O3 = 1:(0.16~0.3), and performing a second exchange on the resulting material at 120~240°C. This preparation method improves the hydrothermal stability of the small-crystal Y molecular sieve and avoids the phenomenon of dealuminization or collapse of the molecular sieve framework when rare earth migrates to the small-crystal molecular sieve using conventional calcination methods.

This invention discloses a catalyst for the production of ethylene and propylene, its preparation method, and its applications. The catalyst comprises the following components: I) 1%–10% of chemical formula A x B y D z A compound of O4; in the chemical formula, the oxidation states of elements A, B, and D are m, n, and p, respectively, satisfying x·m + y·n + z·p = 8, where m, n, and p are integers not greater than 3; the A x B y D z O4 has a spinel structure; II) 0.5%–10% is selected from at least one oxide of rare earth elements, P, Mo, and W; III) 20.0%–55.0% is selected from at least one zeolite of ZSM-5 and ZSM-11; IV) 10%–30% is a binder; V) 25.0%–60.0% is clay. This catalyst is used in the catalytic cracking of petroleum hydrocarbons to produce ethylene and propylene, and features good catalyst stability, low methane yield, and high ethylene and propylene yields.

The invention relates to the technical field of waste gas treatment catalysts, in particular to an SSZ-13 molecular sieve, a preparation method of the SSZ-13 molecular sieve, a NOx removal agent and application of the SSZ-13 molecular sieve. The preparation method comprises the following steps: S1, activating a mixed solution of inorganic alkali, an aluminum source, a silicon source and water at 90-200 DEG C for 1-3 hours to obtain a solution A; s2, adding a template agent into the solution A for hydrothermal reaction, and then filtering, washing, drying and calcining to obtain an SSZ-13 molecular sieve; wherein the template agent has a structure as shown in a formula (X): the formula (X). The SSZ-13 molecular sieve prepared in the invention has excellent catalytic performance, stability and selectivity when being used in a NOx removal agent.

The application belongs to the technical field of catalysts, and particularly relates to an ammonia oxidation catalyst and an internal combustion engine tail gas treatment method. The ammonia oxidation catalyst comprises a first carrier and a catalyst coating arranged on the surface of the first carrier. The catalyst coating comprises a first catalyst component and a second catalyst component. The first catalyst component comprises a noble metal active component and an oxide carrier. The second catalyst component comprises a molecular sieve. The molecular sieve comprises a molecular sieve carrier and an active component. The active component comprises a first metal and an M element. The first metal is selected from one of copper or iron. The M element is selected from at least one of zinc, cobalt, silver, vanadium and bismuth. The catalyst at least solves the problem that existing ammonia oxidation catalysts are difficult to simultaneously achieve high ammonia oxidation efficiency and nitrogen selectivity under full working conditions.

The present application relates to the technical field of molecular sieve synthesis and catalysis, and discloses a composite containing ZSM-5 molecular sieve and a preparation method and application thereof.The composite comprises hydrothermal carbon and ZSM-5 molecular sieve, the mass content of the ZSM-5 molecular sieve is 97-99.5% and the mass content of the hydrothermal carbon is 0.5-3% based on the mass of the composite; wherein, the composite has a peak position in the infrared spectrum at 1500-1600 cm ‑1 and 1700-1800 cm ‑1 . Under the hydrothermal conditions of high temperature and high pressure, the present application uses sucrose and other disaccharides as carbon sources which have lower cost and better thermal stability than glucose and are converted into hydrothermal carbon in situ, effectively modulates the acidity of ZSM-5 molecular sieve at a lower cost, and finally obtains the composite containing ZSM-5 molecular sieve which is applied to the n-pentane cracking reaction and has higher activity and higher olefin selectivity.

The invention provides pseudo-boehmite as well as a preparation method and application thereof.According to the pseudo-boehmite, on the basis of a neutralization method, magnesium salt is introduced into a wet filter cake of the pseudo-boehmite, key parameters such as pH in all steps are controlled, the pseudo-boehmite containing a magnesium aluminate spinel structure is finally prepared, the final product is stable in quality, and the yield is high. And the catalyst has high hydrothermal stability.

The application discloses a kind of multi-level hole composite material and its preparation method and application.The composite material is alumina-silica-zirconia composite material, and the pore distribution of the composite material has the following characteristics: the pore volume of the pore with pore diameter of 10-50nm accounts for 55%-75% of total pore volume, and the pore volume of the pore with pore diameter of 50-200nm accounts for 5%-15% of total pore volume.The multi-level hole composite material has suitable pore distribution, and can be used as a catalyst carrier, especially suitable for use as a carrier of coal tar hydrogenation catalyst.

This invention discloses an SSZ-13 molecular sieve and its preparation method, relating to the field of SSZ-13 molecular sieve synthesis technology, to solve the problems of the basically fixed distribution of aluminum pairs and isolated aluminum in SZ-13 molecular sieves, poor hydrothermal stability, and limited potential for improving catalytic performance. The preparation method includes: pretreating the raw material molecular sieve to form a molecular sieve gel with a six-membered ring framework; adding a silicon source and a template agent to the molecular sieve gel with the six-membered ring framework, and aging it; and crystallizing after aging to obtain the SSZ-13 molecular sieve, wherein the raw material molecular sieve is a Y-type molecular sieve. The SSZ-13 molecular sieve and its preparation method provided by this invention are used for the production of SSZ-13 molecular sieves.

The application discloses an EMT molecular sieve and a preparation method and application thereof. The method comprises the following steps: (1) preparation of a directing agent: the molar ratio of Na2O, Al2O3, SiO2 and H2O in the directing agent is (16-19):1:(4-6):(200-400), preferably 17-18:1:4-6:250-350; (2) synthesis of the molecular sieve: the silicon source, the aluminum source, the alkali source and water are uniformly mixed with the directing agent obtained in the step (1), and then crystallization, filtration, washing, drying and calcination are performed to obtain the EMT molecular sieve. The method is used for synthesizing the EMT molecular sieve by the directing agent method for the first time.

The application discloses a silver-based arsenic removal agent for an ethylene device and a preparation method thereof. The arsenic removal agent comprises the following components in the total mass of the arsenic removal agent being 100%: 0.3-0.8 wt% of an active component silver; 5.0-8.0 wt% of a bimetallic promoter (consisting of 3.0-5.0 wt% of indium oxide and 2.0-3.0 wt% of tin oxide); 1.2-2.0 wt% of a modifier (consisting of 0.8-1.2 wt% of cerium oxide and 0.4-0.8 wt% of a polydopamine carbon skeleton); and the balance of modified alumina; the arsenic removal agent has low cost, high activity and high safety; through carrier surface regulation and multi-component synergy, the arsenic removal agent realizes synchronous deep removal of arsenic, mercury and sulfur under ultra-low silver loading (<1%), effectively inhibits the generation of silver acetylide and carbon deposition, the agent does not need to add an additional mercury / sulfur removal bed, significantly reduces investment, and guarantees long-period stable operation of the ethylene device.