7results about How to "Synthesis temperature is low" patented technology

The application provides a preparation method of a composite molecular sieve and application of the composite molecular sieve in heavy oil cracking, and the preparation method comprises the following steps: dissolving an aluminum source, a silicon source and a structure directing agent in water, and then performing crystallization treatment to obtain a ZSM-5 crystal seed solution; etching Y type molecular sieve in water by using an alkaline substance to form a hollow structure, and then mixing the hollow Y type molecular sieve with acidic silica sol to obtain a solution containing the hollow Y type molecular sieve; mixing the ZSM-5 crystal seed solution and the solution containing the hollow Y type molecular sieve, and then performing temperature crystallization, and then separating a crystallization product, and then performing washing, drying and calcination to obtain a ZSM-5 / Y composite molecular sieve, and then performing ion exchange reaction, and then performing calcination to obtain a H type ZSM-5 / Y composite molecular sieve product. The composite molecular sieve synthesized by the application has the advantages of high activity, good selectivity and the like when the composite molecular sieve is prepared into a catalyst, high liquefied gas and propylene yield can be obtained, and the composite molecular sieve is particularly suitable for the field of petrochemical catalytic cracking.

The application discloses high-entropy rare earth silicate ceramic nano powder and a preparation method and application thereof. The preparation method of the high-entropy rare earth silicate ceramic nano powder comprises the following steps: 1) dissolving rare earth oxide powder in an acid solution to prepare a rare earth salt solution; 2) mixing the rare earth salt solution and a sodium silicate solution, adding ammonia water to perform chemical co-precipitation, then performing standing and aging, and then taking the precipitate to perform drying to obtain a precursor powder; and 3) placing the precursor powder under the condition that the temperature is 1100 DEG C to 1200 DEG C to perform calcination. The high-entropy rare earth silicate ceramic nano powder has excellent characteristics such as small particle size, uniform element distribution, large component space and no impurity phase, and the preparation method has the advantages of low synthesis temperature, simple equipment, simple and controllable process, low industrialization cost and the like, is suitable for being used on a hot end part of an aerospace engine and has a very wide application prospect.

This invention discloses a method for preparing high-entropy ceramic matrix composites using a reactive infiltration process, belonging to the technical field of ceramic matrix composites. The steps are as follows: at least four single-component carbides are ball-milled and mixed with a carbon source, then dispersed in a dispersion liquid to obtain a slurry; continuous fibers are woven into a preform, and an interface layer and a matrix layer are deposited to obtain a semi-dense composite material; the slurry is introduced through vacuum or pressure impregnation; and a high-entropy carbide matrix is ​​generated in situ and densified by reactive infiltration after embedding with a transition metal and its alloy. This invention solves the problems of long process cycles, high porosity, high cost, and insufficient introduction of high-entropy ceramics in existing processes, achieving rapid densification and improving the material's high-temperature stability, oxidation resistance, and ablation resistance. It is suitable for the large-scale production of thermal protection materials for hypersonic vehicles.

This invention relates to a method for preparing Co-based oxide nanosheets based on the oxygen vacancy-regulated reaction mechanism and their application in acidic oxygen evolution reaction (OER). The aim is to address the issue of insufficient efficiency in the electrocatalytic OER. The preparation method includes: 1. Ultrasonic cleaning of carbon cloth; 2. Electrodeposition of cobalt hydroxide precursor using a cobalt salt solution as the electrolyte and the cleaned carbon cloth as the working electrode; 3. Immersion of the cobalt hydroxide precursor in sodium borohydride solution; 4. Electrodeposition of the precursor with oxygen vacancies as the working electrode, a carbon rod as the counter electrode, and a ruthenium metal salt solution as the electrolyte; 5. High-temperature annealing at 400-500°C. The Co-based oxide nanosheets prepared by this invention successfully trigger the LOM mechanism, improving the utilization rate of the precious metal ruthenium, reducing the amount of ruthenium used, and significantly enhancing the catalytic activity and stability of the acidic OER compared to Co3O4.

The application relates to high-sphericity nano tetragonal barium titanate for MLCCs and a preparation method thereof. The technical scheme is as follows: a titanium source, a dissolving agent and potassium perchlorate are mixed to obtain mixed material A; the mixed material A is heated twice under air condition, is preserved, is naturally cooled to obtain a reaction product; the reaction product is washed with distilled water I, is separated, is dried to obtain titanium dioxide powder; the titanium dioxide powder and barium oxide are mixed to obtain mixed material B; the mixed material B, ethylene glycol, pure water and an anionic surfactant are mixed to obtain a mixed solution; the mixed solution is moved to a polytetrafluoroethylene reaction kettle, is placed in a microwave heating furnace, is heated, is preserved, is naturally cooled and is filtered; the filtered product is washed with distilled water II, is separated, is dried to obtain high-sphericity nano tetragonal barium titanate for MLCCs. The product prepared by the application has high purity, high sphericity, small particle size, good dispersity and high tetragonality.

The application discloses a high-entropy rare earth silicate ceramic powder and a preparation method and application thereof. The preparation method of the high-entropy rare earth silicate ceramic powder comprises the following steps: 1) mixing rare earth oxide powder, SiO2 powder, LiCl and KCl and grinding to obtain a mixed powder; and 2) calcining the mixed powder under the condition that the temperature is 700 DEG C to 900 DEG C, and then performing water washing and drying to obtain the high-entropy rare earth silicate ceramic powder. The high-entropy rare earth silicate ceramic powder has the excellent characteristics of high purity, small particle size, uniform element distribution and large component space, and the preparation method has the advantages of short preparation period, low synthesis temperature, small energy consumption and high efficiency, is suitable for being used on a hot end part of an aerospace engine and has a very wide application prospect.

The application discloses a kind of super narrow band purple light fluorescent powder, its chemical general formula is A2M (PO3) 4:zEu 2+ Wherein, A is one or more of Na, K, M is one or more of Ca, Sr, Ba;Super narrow band refers to the half-height width of fluorescent powder emission spectrum is less than 25nm.The application also discloses the preparation method of the super narrow band purple light fluorescent powder, including the following steps: raw material ball milling, slow pre-calcination, multi-section heat preservation and finally increase to 200~350 DEG C, cooling grinding;Finally, under reducing atmosphere, 550~700 DEG C is synthesized, after cooling grinding.The application further discloses the application of the super narrow band purple light fluorescent powder in display device and temperature sensing.The fluorescent powder obtained in the application is super narrow band purple light emission under near ultraviolet light excitation, high color purity, high luminous efficiency, good chemical stability;The production process of fluorescent powder is simple, synthesis temperature is low, green and environmental protection.