阅读说明：本技术 一种立方尖晶石型纳米片状亚铬酸铜的制备方法 (Preparation method of cubic spinel type nano flaky copper chromite ) 是由 张国防 张宇 李吉祯 樊学忠 谢遵园 于 2020-07-02 设计创作，主要内容包括：本发明公开了一种立方尖晶石型纳米片状亚铬酸铜的制备方法,将硝酸铜和硝酸铬溶解于超纯水中,加入六亚甲基四胺作为均匀沉淀剂,加入四乙基氟化铵、氟化铵、氟化钾等含氟化合物作为形貌调节剂,将溶液超声均匀后微波加热至80～95℃,反应后得到前驱体,将该前驱体用无水乙醇和超纯水多次洗涤后干燥、研磨均匀,然后在400～450℃下焙烧,即可得到立方尖晶石型纳米片状亚铬酸铜。本发明制备方法简单,所得立方尖晶石型纳米片状亚铬酸铜纯度高、比表面积大、表面活性位点多、催化效果好,能够显著降低高氯酸铵热分解的高温分解峰温,并且提升高氯酸铵的表观分解热。(The invention discloses a preparation method of cubic spinel type nanometer flaky copper chromite, which comprises the steps of dissolving copper nitrate and chromium nitrate in ultrapure water, adding hexamethylenetetramine as a uniform precipitator, adding fluorine-containing compounds such as tetraethylammonium fluoride, ammonium fluoride and potassium fluoride as morphology regulators, ultrasonically and uniformly heating the solution to 80-95 ℃ by microwave after ultrasonic homogenization, reacting to obtain a precursor, washing the precursor with absolute ethyl alcohol and the ultrapure water for multiple times, drying, grinding uniformly, and roasting at 400-450 ℃ to obtain the cubic spinel type nanometer flaky copper chromite. The preparation method is simple, and the obtained cubic spinel type nano flaky copper chromite has high purity, large specific surface area, many surface active sites and good catalytic effect, can obviously reduce the peak temperature of pyrolysis of ammonium perchlorate and improve the apparent decomposition heat of ammonium perchlorate.)

1. A preparation method of cubic spinel type nano flaky copper chromite is characterized by comprising the following steps:

(1) completely dissolving copper nitrate and chromium nitrate in ultrapure water, then adding hexamethylenetetramine and a fluorine-containing compound, and performing ultrasonic treatment to obtain a uniform solution; wherein the fluorine-containing compound is any one of tetraethylammonium fluoride, ammonium fluoride and potassium fluoride;

(2) heating the solution in the step (1) to 80-95 ℃ by microwave, reacting at constant temperature for 35-45 min, and obtaining green turbid liquid after the reaction is finished;

(3) carrying out centrifugal separation and washing on the turbid liquid obtained in the step (2), and drying and grinding the obtained green precipitate to obtain a precursor;

(4) and (4) heating the precursor in the step (3) to 400-450 ℃, and roasting at a constant temperature for 2.5-3.5 h to obtain the cubic spinel type nano flaky copper chromite.

2. The method for preparing cubic spinel type nano flaky copper chromite according to claim 1, characterized in that: in the step (1), the molar ratio of the copper nitrate to the chromium nitrate to the hexamethylenetetramine to the fluorine-containing compound is 1:2: 4.5-6: 4.5-5.5.

3. The method for preparing cubic spinel type nano flaky copper chromite according to claim 1, characterized in that: in the step (1), the ultrasonic time is 20-30 min.

4. The method for preparing cubic spinel type nano flaky copper chromite according to claim 1, characterized in that: in the step (2), the microwave heating power is 500-600W.

5. The method for preparing cubic spinel type nano flaky copper chromite according to claim 1, characterized in that: in the step (3), the drying temperature is 80-100 ℃, and the drying time is 10-15 h.

6. The method for preparing cubic spinel type nano flaky copper chromite according to claim 1, characterized in that: in the step (4), the heating rate is 0.5-2 ℃/min.

Technical Field

The invention belongs to the technical field of solid propellants, and particularly relates to a preparation method of cubic spinel type nanometer flaky copper chromite.

Background

Spinel type copper chromite (CuCr)₂O₄) Is considered to be a multifunctional material and is widely applied to the fields of photocatalysis, semiconductors, catalytic hydrogenation and the like. In recent years, researchers have discovered CuCr₂O₄Has excellent catalytic performance for the thermal decomposition of Ammonium Perchlorate (AP). Li Wei et al (Solid State science, 2007,9(8): 750-. Haogazi (Boehringer, et al) (Boehringer, Arisaema₂O₄Preparing 60nm nano CuCr as raw material₂O₄Using solvent evaporation method to evaporate CuCr₂O₄Mixing with AP, and testing to obtain the final product₂O₄The pyrolysis temperature of AP can be reduced by 67 ℃ and the apparent decomposition heat can be increased by 424.57J/g. The superfine pure cubic spinel type CuCr is synthesized by using a citric acid coordination method by using the Chinese herbal medicine of Shenyujing, etc. (Denko dynasty, dynasty and dynasty, 2012,35(4):41-44)₂O₄The peak of AP pyrolysis can be advanced to 339.6 ℃, the burning rate of the composite modified double-base propellant is improved from 35.84mm/s to 61.00mm/s under 6MPa, and the pressure index is reduced from 0.62 to 0.14.

Disclosure of Invention

The invention aims to provide cubic spinel type nano flaky CuCr with large specific surface area, multiple active sites and good catalytic performance₂O₄The preparation method of (1).

Aiming at the purposes, the technical scheme adopted by the invention comprises the following steps:

1. completely dissolving copper nitrate and chromium nitrate in ultrapure water, then adding hexamethylenetetramine and a fluorine-containing compound, and performing ultrasonic treatment to obtain a uniform solution; wherein, the fluorine-containing compound is any one of tetraethyl ammonium fluoride, ammonium fluoride and potassium fluoride.

2. And (3) heating the solution obtained in the step (1) to 80-95 ℃ by microwave, reacting at a constant temperature for 35-45 min, and obtaining a green turbid solution after the reaction is finished.

3. And (3) carrying out centrifugal separation and washing on the turbid liquid obtained in the step (2), and drying and grinding the obtained green precipitate to obtain a precursor.

4. And (3) heating the precursor in the step (3) to 400-450 ℃, and roasting at a constant temperature for 2.5-3.5 h to obtain the cubic spinel type nano flaky copper chromite.

In the step 1, the molar ratio of the copper nitrate to the chromium nitrate to the hexamethylenetetramine to the fluorine-containing compound is preferably 1:2:4.5 to 6:4.5 to 5.5.

In the step 1, the ultrasonic treatment time is 20-30 min.

In the step 2, the microwave heating power is 500-600W.

In the step 3, the drying temperature is 80-100 ℃, and the drying time is 10-15 h.

In the step 4, the heating rate is preferably 0.5-2 ℃/min.

The invention has the following beneficial effects:

the preparation method is simple, has high yield, and can obtain CuCr at low calcination temperature₂O₄And the obtained CuCr₂O₄The cubic spinel nano-flake is high in purity, the thickness of the cubic spinel nano-flake is about 10-40 nm, and the specific surface area of the cubic spinel nano-flake is 90-100 m²·g^-1The catalyst has the advantages of large specific surface area, more surface active sites and good catalytic effect, can obviously reduce the peak temperature of pyrolysis of ammonium perchlorate and improve the apparent decomposition heat of ammonium perchlorate.

Drawings

FIG. 1 shows cubic spinel type nano-flake CuCr prepared in examples 1 to 3₂O₄X-ray diffraction pattern of (a).

FIG. 2 shows cubic spinel type nano-flake CuCr prepared in example 1₂O₄Scanning electron microscopy of (a).

FIG. 3 is a cubic spinel nano-platelet CuCr prepared in example 2₂O₄Scanning electron microscopy of (a).

FIG. 4 is a cubic spinel nano-platelet CuCr prepared in example 3₂O₄Scanning electron microscopy of (a).

FIG. 5 is a graph of AP with 5% of the cubic spinel nano-flake CuCr prepared in examples 1 to 3 added₂O₄And differential scanning calorimetry analysis of pure AP.

Detailed Description

The invention will be further described in detail with reference to the following figures and examples, but the scope of the invention is not limited to these examples.