4 results about "Isomorphous substitution" patented technology

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.

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.