9 results about "Isomorphous substitution" patented technology

The present invention relates to the technical field of soil regeneration, and specifically to a method for degrading cadmium-contaminated soil based on a heavy metal passivator, comprising the following steps: S1, preparation of PB-MgAl-LDH; S2, magnetic modification of PB-MgAl-LDH; S3, preparation of a passivator; S4, soil remediation. The preferred pine bark and magnesium-aluminum hydrotalcite in a specific growth position of the present invention are prepared by steady-state coprecipitation to obtain a solid powder with good specific surface area and adsorption activity. After magnetic modification, the unique interlayer structure has magnetism, is easy to generate negative charges, accelerates the adsorption of cadmium to balance the charges, and simultaneously undergoes lattice diffusion, isomorphous substitution and other effects, showing a strong ion exchange capacity and adsorption capacity for cadmium ions.

The present invention provides a catalytic cracking catalyst, a preparation method, and an application thereof. The preparation method comprises: subjecting a NaY molecular sieve containing the metal element Mn in its framework and having a molar ratio of MnO2 to Al2O3 of 0.01-10.0 to an isomorphous substitution reaction at 200-600°C with gaseous SiCl4 at a mass ratio of 0.1-20:1, followed by calcination to obtain a high silicon-aluminum ratio Y molecular sieve containing the metal element Mn in its framework; and then utilizing the Y molecular sieve in combination with a ZSM-5 molecular sieve, natural clay, and an inorganic oxide binder to prepare a catalytic cracking catalyst; based on the total dry weight of the raw materials used to prepare the catalytic cracking catalyst being 100%, the Y molecular sieve accounts for 15-35%, the ZSM-5 molecular sieve accounts for 0-20%, the natural clay accounts for 40-50%, and the inorganic oxide binder accounts for 10-45% as an inorganic oxide.

This invention relates to the field of sodium-ion battery technology, and in particular to a polyanion-doped sodium vanadium manganese phosphate cathode material, its preparation method, and a sodium-ion battery. The general chemical formula of the polyanion-doped sodium vanadium manganese phosphate cathode material provided by this invention is Na₄VMn(PO₄). 3‑x (SiO4) x Where x is 0.01~0.08; SiO4 4‑ PO4 in the crystal framework is located by isomorphous substitution. 3‑ Site. The polyanion-doped sodium manganese phosphate cathode material of the present invention, SiO4 4‑ Partial PO4 substitution 3‑ The site can directly expand the migration channel size of sodium ions from a crystallographic perspective, effectively reducing the diffusion barrier of sodium ions; the stronger Si-O bond energy enhances the overall stability of the crystal structure. This synergistic effect of expanding channels and strengthening the framework effectively inhibits structural degradation during cycling, especially alleviating the degradation of Mn. 3+ The Jahn-Teller effect.

The application discloses a method for synthesizing zirconium modified A type molecular sieve by using fly ash as raw material, and belongs to the technical field of resource comprehensive utilization. The preparation steps comprise one-pot synthesis of zirconium metal molecular sieve through raw material mixing, alkali fusion activation, direct addition of zirconium solution, stirring and aging, crystallization, suction filtration and washing and drying. The method does not need to introduce zirconium through post-processing mode, and reduces the generation of waste liquid in the ion exchange or isomorphous substitution process. Meanwhile, since no template agent is used in the preparation process, the molecular sieve does not need to be calcined to remove the template agent, the zirconium content of the synthesized molecular sieve is as high as 10.83wt%, the adsorbent has high adsorption capacity for As(V) in a solution, the maximum adsorption capacity can reach 104.63mg / g, and the adsorbent can be recycled for multiple times. The synthesis method is simple, effectively reduces the generation of pollutants and energy consumption in the synthesis process, the zirconium content of the synthesized molecular sieve is high, and the molecular sieve has high adsorption capacity for As(V).

The application provides a strong-acid FAU type molecular sieve and a preparation method thereof. The preparation method comprises the following steps: carrying out isomorphous substitution reaction on a FAU type molecular sieve containing a metal element Zr in a skeleton and gaseous SiCl4 at a mass ratio of 0.1-20:1, and then obtaining a high-silicon-aluminum ratio FAU type molecular sieve through calcination; the reaction temperature of the isomorphous substitution reaction is 200-600 DEG C; and the molar ratio of ZrO2 to Al2O3 in the FAU type molecular sieve containing the metal element Zr in the skeleton is 0.01-10.0. The technical scheme provided by the application realizes a substantial increase in the strong-acid content of the FAU type molecular sieve through the isomorphous substitution of the FAU type molecular sieve containing the metal element Zr in the skeleton and the gaseous SiCl4 and then the calcination, and the prepared FAU type molecular sieve also has high crystallinity and a high skeleton silicon-aluminum ratio.

The invention discloses a preparation method of a carbon quantum dot reinforced hydrotalcite material and application of the carbon quantum dot reinforced hydrotalcite material as a heavy metal adsorbent. The method comprises the following steps: adding hydrotalcite and carbon quantum dots into ultrapure water, carrying out vigorous stirring reaction at room temperature, centrifuging, washing with ethanol, and drying. According to the invention, hydrotalcite is subjected to non-covalent functionalization by using carbon quantum dots rich in-NH2 and-COOH, such that the carbon quantum dot reinforced hydrotalcite material is obtained. -NH2 and-COOH in the carbon quantum dots have relatively strong binding capacity to calcium ions dissolved out from the hydrotalcite laminate, and after the divalent metal is coordinated with the groups on the surfaces of the carbon quantum dots, more calcium vacancies with lower energy barriers are formed on the hydrotalcite laminate. The existence of calcium vacancies is beneficial to rapid generation of isomorphous substitution and generation of a cadmium hydroxide molecular form, and the adsorption speed and the adsorption efficiency of the material are improved. The carbon quantum dot reinforced hydrotalcite material has an important application prospect in the field of heavy metal pollution emergency treatment or high-performance adsorbent development.

The invention provides a homonuclear hetero-coordinated double-M monatomic synergistic catalyst as well as a preparation method and application of the homonuclear hetero-coordinated double-M monatomic synergistic catalyst. The preparation method of the catalyst comprises the following steps: by taking ultrathin flaky MoS2 as a carrier, anchoring and isomorphic substitution of active M species are realized based on the characteristics of abundant S vacancies on the edge of the ultrathin MoS2 and periodic arrangement of a basal plane by utilizing a temperature-controlled impregnation strategy, and the homonuclear heterocoordinated double-monatomic synergistic Ms / MoS2-NF catalyst is obtained after inert and reducing gas heat treatment. The catalyst has two active metal M sites of an M1-Mo2 monatomic and an M1-S6 monatomic, and the distance between the two M atoms is adjacent and controllable, so that a strong synergistic effect is generated, an M1-S6 / M1-Mo2 homonuclear hetero-coordinated double-M monatomic synergistic active center is formed, and the balance of activity, selectivity and stability of the monatomic catalyst in acetylene selective hydrogenation reaction is realized. The catalyst is mild in synthesis condition and simple and convenient in process, shows excellent catalytic performance in an acetylene selective hydrogenation reaction process, and has good recoverability and reusability.

The preparation method comprises the following steps: dissolving MgSO4. 7H2O, Ce (NO3) 3.6 H2O and FeCl2. 4H2O in deionized water, adjusting the pH value of the obtained mixed solution to 8.8-9.0 by using dilute ammonia water, standing and aging for 60 minutes, centrifuging, washing by using deionized water until the pH does not change any more, and drying to obtain Fe (OH) 2 / Ce (OH) 3 / Mg (OH) 2 mixed powder; the Fe (OH) 2 / Ce (OH) 3 / Mg (OH) 2 mixed powder is ground and placed in a crucible to be calcined for 2 hours in the air atmosphere of 700 DEG C, Fe (at) CeO2-x / MgO powder is obtained, the obtained isomorphic substitution catalytic ozonation nano-catalyst has rich oxygen vacancies and Lewis acid sites, ozone can be adsorbed, generation of active oxygen species is promoted, the preparation method is simple, the prepared catalyst is high in catalytic efficiency, and the catalyst can be applied to the field of catalytic ozonation catalysis. New tetracycline antibiotic pollutants can be effectively degraded and mineralized, and the generation potential of disinfection by-products of tetracycline can be synchronously and remarkably controlled.

This invention belongs to the field of catalyst materials technology, disclosing a mesoporous composite metal oxide catalyst for ethanol-to-olefins conversion, its preparation method, and its application. The catalyst is a Mg-Al-X composite metal oxide with a mesoporous structure and spinel crystal phase, where X is at least one of Sc, Sn, and Ce. It is prepared through template-free hydrothermal synthesis and in-situ isomorphous substitution, exhibiting a uniform distribution of active sites and synergistic acid-base dual-function. This invention does not use expensive template agents, has a simple preparation process, low cost, and low waste emissions, showing good industrialization prospects. The obtained catalyst possesses both high activity and high selectivity, with an ethanol conversion rate of up to 82.91% and an olefin selectivity of up to 99.21% under optimized conditions, and excellent thermal stability at 375℃ for 2.37 h. ‑1 No significant deactivation was observed after 150 hours of continuous reaction; the catalyst is suitable for reaction at 275–400℃ for 0.95–4.73 hours. ‑1 With a wide operating range and operating at normal pressure, it meets the green chemical needs of biomass ethanol to produce low-carbon olefins, and has significant economic and social benefits.