阅读说明：本技术 一种磷化钴空心微球的制备方法及其产品和应用 (Preparation method of cobalt phosphide hollow microspheres and product and application thereof ) 是由 崔大祥 徐少洪 王敬锋 林琳 王岩岩 金彩虹 于 2020-07-08 设计创作，主要内容包括：本发明是一种磷化钴空心微球的制备方法及其产品和应用,通过将模板法制备磷化钴空心微球来提高其催化性能的方法,首先将苯乙烯单体与乳化剂加入去离子水中,剧烈搅拌形成乳液之后加入引发剂,并于水浴锅中反应制得聚苯乙烯微球；然后将其加入去离子水与乙醇的混合溶液中,加入乙酸钴与氨水后于水浴锅中反应,离心洗涤干燥之后在氢氩混合气的保护下于管式炉中焙烧；最后将上述粉末与磷源混合之后在保护性气体氛围下于管式炉中焙烧,自然冷却至室温之后即得磷化钴空心微球。采用本发明所述方法制备的磷化钴空心微球,价格低廉,无毒无害,比表面积大,催化性能优异,催化硼烷氨释放氢气速率高。(The invention relates to a preparation method of cobalt phosphide hollow microspheres and a product and application thereof.A method for improving the catalytic performance of the cobalt phosphide hollow microspheres by a template method is characterized in that a styrene monomer and an emulsifier are added into deionized water, and an initiator is added after the mixture is vigorously stirred to form an emulsion and reacts in a water bath kettle to prepare polystyrene microspheres; then adding the cobalt acetate and ammonia water into a mixed solution of deionized water and ethanol, reacting in a water bath, centrifugally washing, drying, and roasting in a tubular furnace under the protection of hydrogen-argon mixed gas; and finally, mixing the powder with a phosphorus source, roasting in a tubular furnace in a protective gas atmosphere, and naturally cooling to room temperature to obtain the cobalt phosphide hollow microspheres. The cobalt phosphide hollow microspheres prepared by the method have the advantages of low price, no toxicity, no harm, large specific surface area, excellent catalytic performance and high hydrogen release rate in catalyzing ammonia borane.)

1. A preparation method of cobalt phosphide hollow microspheres is characterized in that the method for improving the catalytic performance of the cobalt phosphide hollow microspheres by a template method comprises the following steps:

1) preparing polystyrene microspheres: weighing a styrene monomer, an initiator, an emulsifier and deionized water, wherein the mass ratio of the styrene monomer to the initiator is 1 (0.0001-1), and the mass ratio of the styrene monomer to the emulsifier is 1 (0.0001-1); the mass ratio of the styrene to the deionized water is 1 (1-1000); firstly, adding a styrene monomer and an emulsifier into deionized water, violently stirring to form an emulsion, then adding the emulsifier while stirring, reacting in a water bath kettle, filtering and washing to obtain polystyrene microspheres;

2) preparing the metal cobalt hollow microspheres: adding the prepared polystyrene microspheres into a mixed solution of deionized water and ethanol, and then adding cobalt acetate, wherein the mass ratio of the polystyrene microspheres to the cobalt acetate is 1: 1-500; adding ammonia water after fully stirring, wherein the mass ratio of the polystyrene microspheres to the ammonia water is 1: 0.001-100; reacting in a water bath kettle under the condition of stirring, centrifugally washing, roasting the obtained powder in a tubular furnace under the protection of hydrogen-argon mixed gas, and cooling to obtain the cobalt hollow microspheres;

3) And mixing the prepared cobalt hollow microspheres with a phosphorus source, roasting in a tubular furnace at 200-700 ℃ for 0.5-12 h under the protection of protective gas, and naturally cooling to obtain the cobalt phosphide hollow microspheres.

2. The method for preparing the cobalt phosphide hollow microspheres according to claim 1, wherein the initiator in the step 1) is one of or a mixture of methyl ethyl ketone peroxide, potassium persulfate, dibenzoyl peroxide and dicumyl peroxide; the emulsifier is one or a mixture of sodium dodecyl benzene sulfonate, hexadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium chloride, polyvinylpyrrolidone or polyethylene glycol; the water bath kettle is subjected to water bath reaction for 1-36 hours at the temperature of 30-100 ℃.

3. The preparation method of the cobalt phosphide hollow microspheres according to claim 1, wherein the mass ratio of the deionized water to the ethanol in the step 2) is 1: 0.01-100; the temperature of the water bath kettle is 30-100 ℃; the water bath reaction time is 1-36 h.

4. The preparation method of the cobalt phosphide hollow microspheres according to claim 1, wherein the roasting temperature in the step 2) is 200-700 ℃ and the roasting time is 0.5-12 h.

5. The method for preparing the cobalt phosphide hollow microspheres according to claim 1, wherein the phosphorus source in the step 3) is one of or a mixture of sodium hypophosphite, potassium phosphate, disodium hydrogen phosphate and sodium dihydrogen phosphate; the protective gas is one of nitrogen and argon or the mixture thereof; the mass ratio of the cobalt hollow microspheres to the phosphorus source is 1: 0.1-500.

6. Hollow cobalt phosphide microspheres prepared according to the process of any one of claims 1 to 5.

7. The application of the cobalt phosphide hollow microspheres as described in claim 6 as a catalyst in catalytic degradation of ammonia borane for hydrogen production.

Technical Field

The invention belongs to the field of nano powder preparation, and particularly relates to a preparation method of cobalt phosphide hollow microspheres and a product and application thereof.

Background

In recent years, with rapid development of world economy, demand and consumption of fossil materials have increased greatly. Since fossil raw materials are non-renewable energy sources, the reserves thereof have not been able to meet the needs of people. In addition, the release of carbon dioxide causes greenhouse effect and seriously affects human survival, so that the development of alternative energy sources is in great tendency. Among them, hydrogen has become a hot research point due to its regenerability and non-pollution.

At present, catalytic steam reforming, coal gasification, petroleum cracking and other methods are mainly adopted for industrially preparing hydrogen, but the methods generally have some defects, such as high energy consumption, impure prepared hydrogen, large amount of discharged carbon dioxide and the like. The catalytic hydrolysis of borohydrides such as sodium borohydride, borane ammonia, lithium borohydride and the like provides an environmentally friendly approach to hydrogen production. Among them, ammonia borane is an ideal material for hydrogen production by hydrolysis due to its characteristics of high theoretical hydrogen content, relatively high environmental stability, no toxicity, environmental friendliness, etc. However, large-scale application of borane ammonia also relies on the development of highly efficient, stable and inexpensive catalysts.

Transition metal phosphides are a stable and highly efficient class of catalysts. Phosphorus atoms enter transition metal lattices to form interstitial compounds, so that the catalyst has extremely strong conductivity, high thermal stability and chemical stability, and can be used as a catalyst with excellent performance to be applied to the preparation of hydrogen through the catalytic degradation of ammonia borane. Among them, cobalt phosphide attracts researchers' attention due to its excellent properties, but its specific surface area is too low, active sites are too few, and these adverse factors limit the exertion of its catalytic efficiency, so that it still cannot meet the requirement of commercial use.

In order to improve the capability of cobalt phosphide for catalyzing and degrading ammonia borane to prepare hydrogen, the invention improves the surface reaction active site by preparing the cobalt phosphide hollow microsphere, thereby improving the catalytic efficiency. The method comprises the steps of preparing polystyrene spheres, growing and preparing metal cobalt on the surfaces of the polystyrene spheres to prepare the cobalt metal hollow microspheres, and preparing the cobalt phosphide hollow microspheres in a phosphorization mode. The cobalt phosphide hollow microspheres prepared by the method are low in price, non-toxic, harmless, large in specific surface area, excellent in catalytic performance and high in hydrogen release rate when catalyzing ammonia borane.

Disclosure of Invention

Aiming at the defect of low catalytic performance of cobalt phosphide, the invention aims to provide a preparation method of cobalt phosphide hollow microspheres.

Yet another object of the present invention is to: provides a cobalt phosphide hollow microsphere product prepared by the method.

Yet another object of the present invention is to: provides an application of the product.

The purpose of the invention is realized by the following scheme: a preparation method of cobalt phosphide hollow microspheres is characterized in that the method for improving the catalytic performance of the cobalt phosphide hollow microspheres by a template method comprises the following specific steps:

1) accurately weighing a styrene monomer, an initiator, an emulsifier and deionized water according to a formula, firstly adding the styrene monomer and the emulsifier into the deionized water, violently stirring to form an emulsion, then adding the emulsifier while stirring, reacting in a water bath for a period of time, and filtering and washing to obtain polystyrene microspheres;

2) adding the prepared polystyrene spheres into a mixed solution of deionized water and ethanol, then adding a certain amount of cobalt acetate, fully stirring, then adding ammonia water, reacting in a water bath kettle for a period of time under the condition of stirring, centrifugally washing, roasting the obtained powder in a tubular furnace at a certain temperature for a period of time under the protection of hydrogen-argon mixed gas, and cooling to obtain the metal cobalt hollow microspheres;

3) Mixing the prepared cobalt hollow microspheres with a phosphorus source, roasting in a tubular furnace at 200-700 ℃ for 0.5-12 h under the protection of protective gas, and naturally cooling to obtain the cobalt phosphide hollow microspheres.

In the step 1), the initiator is one of or a mixture of methyl ethyl ketone peroxide, potassium persulfate, dibenzoyl peroxide or dicumyl peroxide; the emulsifier is one or a mixture of sodium dodecyl benzene sulfonate, hexadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium chloride, polyvinylpyrrolidone or polyethylene glycol; the mass ratio of the styrene monomer to the initiator is 1: 0.0001-1, and the mass ratio of the styrene monomer to the emulsifier is 1: 0.0001-1; the mass ratio of the styrene to the deionized water is 1: 1-1000; the temperature of the water bath kettle is 30-100 ℃; the water bath reaction time is 1-36 h.

The mass ratio of the deionized water to the ethanol in the step 2) is 1: 0.01-100; the mass ratio of the polystyrene microspheres to the cobalt acetate is 1: 1-500; the mass ratio of the polystyrene microspheres to the ammonia water is 1: 0.001-100; the temperature of the water bath kettle is 30-100 ℃; the water bath reaction time is 1-36 h.

In the step 2), the roasting temperature is 200-700 ℃, and the roasting time is 0.5-12 h.

In the step 3), the phosphorus source is one of or a mixture of sodium hypophosphite, potassium phosphate, disodium hydrogen phosphate and sodium dihydrogen phosphate; the protective gas is one of nitrogen and argon or the mixture thereof; the mass ratio of the cobalt hollow microspheres to the phosphorus source is 1: 0.1-500.

The invention provides a cobalt phosphide hollow microsphere prepared by any one of the methods.

The invention provides an application of cobalt phosphide hollow microspheres as a catalyst in hydrogen production by catalytic degradation of ammonia borane.

The method for preparing the cobalt phosphide hollow microspheres provided by the invention comprises the following steps: weighing a styrene monomer, an initiator, an emulsifier and deionized water, firstly adding the styrene monomer and the emulsifier into the deionized water, violently stirring to form an emulsion, then adding the initiator, and reacting in a water bath to obtain polystyrene microspheres; then adding the cobalt acetate and ammonia water into a mixed solution of deionized water and ethanol, reacting in a water bath, centrifugally washing, drying, and roasting in a tubular furnace under the protection of hydrogen-argon mixed gas; and finally, mixing the powder with a phosphorus source, roasting in a tubular furnace in a protective gas atmosphere, and naturally cooling to room temperature to obtain the cobalt phosphide hollow microspheres.

The cobalt phosphide hollow microspheres prepared by the method have the advantages of low price, no toxicity, no harm, large specific surface area, excellent catalytic performance and high hydrogen release rate in catalyzing ammonia borane.

Drawings

FIG. 1 is a transmission electron micrograph of cobalt phosphide hollow microspheres prepared in example 1 of the present invention.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.