CN105126884A - Ammoniaborane or Hydrazine Hydrate Catalyzed Hydrogen Interpretation System Containing Nano-Metal Phosphide MxPy Catalyst and Its Application - Google Patents

Abstract

The invention discloses an ammonia borane or hydrazine hydrate catalytic hydrolysis hydrogen system containing a nanometer metal _{phosphide MxPy} catalyst and its application. The system includes a nano-metal phosphide catalyst, ammonia borane or hydrazine hydrate, and water; the nano-metal phosphide catalyst can be expressed as M _x P _y , wherein M is Fe, Co, Ni or Cu, 1≤x≤ 20, 1≤y≤10. The invention uses a cheap metal phosphide M _x P _y catalyst to catalyze the hydrolysis of ammonia borane or the release of hydrogen from hydrazine hydrate, and the cost is low. The catalyst is stable and safe in nature, high in efficiency in catalytic hydrogen release, and the raw materials required for preparation are cheap and the preparation method is simple. The catalytic hydrogen release system of the present invention is a heterogeneous catalytic reaction, which facilitates the recovery and utilization of the catalyst.

Description

Ammoniaborane or Hydrazine Hydrate Catalyzed Hydrogen Interpretation System Containing Nano-Metal Phosphide MxPy Catalyst and Its Application

technical field

The invention relates to the field of hydrogen fuel cells. More specifically, it relates to an ammonia borane or hydrazine hydrate catalyzed water-interpreting hydrogen system containing nanometer metal _{phosphide MxPy} catalyst and its application.

Background technique

Hydrogen storage is one of the problems restricting the arrival of hydrogen economy. Storing hydrogen at high pressure or low temperature is neither safe nor cheap. How to store it safely and efficiently is the technical bottleneck facing the application of hydrogen energy in portable power sources and vehicle fuel cells. At present, a lot of research involves the storage and release of hydrogen in chemical hydrogen storage materials, looking for chemical hydrogen storage materials with high hydrogen content and extremely small relative molecular weight, and what methods are used to make the chemical hydrogen storage materials work under normal pressure and low temperature. The rapid and timely release of contained hydrogen is the key to the practical application of hydrogen. Ammonia borane (BH ₃ NH ₃ , AB), as a leader in hydrogen storage materials, deserves its name. There are various ways to make ammonia borane release hydrogen. For now, the most used and mildest method is to add a metal catalyst to its aqueous solution. There are various catalyst systems that have been reported, but in general there are The following three types: single metal nanoparticle system, alloy nanoparticle system and metal nanoparticle system with carrier. Among the many catalytic systems, rare and precious metals (Pt, Rh, Pd, Ir, Au, Ru) and cheap metals (Fe, Co, Ni, Cu) are covered, and the catalytic efficiency of systems containing rare and precious metals is much higher than that of cheap metals. systems, however, the availability and price of scarce metals constrain their commercialization. In recent years, although several non-noble metal nanoparticle systems with high catalytic efficiency have appeared, the non-noble metal nanoparticles are unstable to air or involve some additional carrier materials or some stabilizers and sodium borohydride are added to the system during the catalytic process. (NaBH ₄ ) Strong reducing agent. So it is extremely important to find and develop a catalyst that is efficient, cheap, safe to use, stable and has not been used in this field before.

At present, the use of metal nanoparticles to catalyze ammonia borane water to explain the hydrogen system still has the following problems: First, it is often necessary to rely on rare and precious metals to achieve high catalytic hydrogen release efficiency, and the efficiency of hydrogen release using non-noble metal catalysts is still low. high. Second, the stability of non-precious metal catalysts needs to be improved. Third, research in this field has been around Pt, Rh, Pd, Au, Ru, Fe, Co, Ni and Cu nanoparticles or alloy nanoparticles of these metals, the main measure is to change the shape, size and degree of dispersion of nanoparticles , no new catalysts were introduced for a long time.

Contents of the invention

An object of the present invention is to provide an ammonia borane or hydrazine hydrate catalyzed water-interpreting hydrogen system containing a nanometer metal _{phosphide MxPy} catalyst. The system can quickly produce hydrogen, and the catalyst used does not contain rare and precious metals, with low cost, high efficiency, safe use, good stability and recyclability.

Another object of the present invention is to provide an application of an ammonia borane or hydrazine hydrate catalyst containing a nanometer metal phosphide M _x P _y catalyst in a water-interpreting hydrogen system.

Metal phosphides have many unique physical and chemical properties, the most striking of which is nickel phosphide (Ni ₂ P). Nickel phosphide (Ni ₂ P) exhibits high catalytic activity and stability from photocatalytic water decomposition to hydrogen production, electrocatalytic water decomposition to hydrogen production, hydrodenitrogenation and hydrodesulfurization, etc. Ni ₂ P nanoparticles can be made either water-soluble or water-insoluble. In order to enhance the control of the hydrogen release system, water-insoluble Ni ₂ P nanoparticles were chosen to be synthesized. In the heterogeneous system, the start and end of the hydrolysis reaction can be controlled by separating different phases, and simple methods such as centrifugation can also be used. to recover Ni ₂ P nanoparticles. Based on this, the present application proposes for the first time a nanometer metal phosphide catalyst suitable for ammonia borane or hydrazine hydrate catalyzed hydrolysis hydrogen system.

To achieve the above object, the present invention adopts the following technical solutions:

A kind of ammonia borane or hydrazine hydrate catalytic water interpretation hydrogen system containing nanometer metal phosphide M _x P _y catalyst, said system includes nanometer metal phosphide catalyst, ammonia borane or hydrazine hydrate, and water; said nanometer metal phosphorus The compound catalyst can be expressed as M _x P _y , wherein M is Fe, Co, Ni or Cu, 1≤x≤20, 1≤y≤10.

Preferably, the nano-metal phosphide catalyst is water-insoluble.

Preferably, the size of the nano-metal phosphide catalyst is no more than 100 nm.

Preferably, the preparation method of the nano-metal phosphide catalyst comprises the steps of:

1) Put the metal salt, sodium citrate, alkali and water in a container and mix evenly, and stir to obtain a colloid; separate and collect the colloid, wash, and dry to obtain a metal hydroxide precursor;

2) The metal hydroxide precursor obtained in step 1) is fully mixed and ground with sodium hypophosphite, calcined in an inert atmosphere, cooled to room temperature, washed with distilled water and dilute hydrochloric acid, and the nanometer metal phosphide catalyst is obtained.

Preferably, in step 1), the mass ratio of the metal salt to sodium citrate is 1:0.25-0.75, appropriate amount of alkali and water; the stirring time is 1-300min; the drying temperature is 323-423K.

Preferably, in step 1), the metal salt is selected from iron salt, cobalt salt, nickel salt or copper salt; the alkali is selected from sodium hydroxide, potassium hydroxide or ammonia water, etc.

Preferably, in step 1), the iron salt is selected from ferric chloride, ferric nitrate or ferrous sulfate; the cobalt salt is selected from cobalt chloride, cobalt nitrate or cobalt acetate; the nickel salt is selected from Nickel chloride, nickel sulfate, nickel nitrate or nickel oxalate, etc.; the copper salt is selected from copper chloride or copper sulfate, etc.

Preferably, in step 2), the mass ratio of the metal hydroxide precursor to sodium hypophosphite is 1:2-10.

Preferably, in step 2), the inert atmosphere is argon; the calcination temperature is 523-673K; the calcination time is 0.5-6h.

Preferably, the preparation method of the nanometer metal phosphide catalyst can also be:

The metal salts except nitrate and sodium hypophosphite are fully mixed and ground, calcined in an inert atmosphere, cooled to room temperature, washed with distilled water and dilute hydrochloric acid, and the nanometer metal phosphide catalyst is obtained.

Preferably, the preparation method of the nanometer metal phosphide catalyst can also be:

Dissolve the metal salt in distilled water or a mixed solvent of distilled water and alcohol in any proportion, then add red phosphorus or white phosphorus to obtain a mixed system, and conduct a hydrothermal reaction on the mixed system; after cooling to room temperature, centrifuge to collect the precipitate and wash it with distilled water Precipitate, namely obtain nano metal phosphide catalyst.

Sodium acetate, and/or hexamethylenetetramine, and/or surfactants may also be added to the mixing system in the above preparation method.

Preferably, the surfactant is selected from one or more of polyvinylpyrrolidone, acrylamide, sodium dodecylbenzenesulfonate and cetyltrimethylammonium bromide; the alcohol is selected from methanol , ethanol, ethylene glycol, glycerol and polyethylene glycol; the molar ratio of phosphorus to metal is 1:1-30; the temperature of the hydrothermal reaction is 403-473K, water The thermal reaction time is 6-30h.

The present invention also provides an application of the above-mentioned ammonia borane or hydrazine hydrate catalytic water- _separation hydrogen system containing nanometer metal phosphide _MxPy catalyst in the field of catalytic water-separation hydrogen.

In the prior art, the catalysts used in the general hydrolysis hydrogen system are platinum, ruthenium, gold, palladium, iridium, silver, iron, cobalt, nickel, copper and other nanomaterials or alloy nanomaterials of the above metals. For: precious metal nanomaterials are expensive; most cheap metal nanomaterials are inefficient and unstable to air; metal nanoparticles in many of the above systems are prone to agglomeration; some cheap metal nanoparticles have safety hazards; some cheap systems have an induction period; and This field has been researching on metal nanoparticles or metal alloy nanoparticles, the main measure is to change the shape, size and degree of dispersion of nanoparticles, and no new catalyst has been introduced for a long time. The present application found for the first time that by optimizing the size and shape of the metal phosphide, applying the prepared nano-metal phosphide that meets the conditions of catalytic water-interpretation hydrogen to ammonia borane or hydrazine hydrate catalytic water-interpretation hydrogen system can produce good Hydrogen release effect, the system has the advantages of cheap materials, low cost, high catalytic efficiency, recyclability, safety, etc. Once the catalyst comes into contact with the aqueous solution of ammonia borane or hydrazine hydrate, it will immediately catalyze and generate a large amount of hydrogen, which is well overcome The disadvantages of the prior art, such as high catalyst cost, low efficiency of cheap system, complicated operation and instability, have been solved, and a new field has been opened up for the research of catalyst selection and water-interpreted hydrogen catalytic system.

The beneficial effects of the present invention are as follows:

1. The present invention uses a cheap metal phosphide M _x P _y catalyst to catalyze ammonia borane water to decompose hydrogen, and the cost is low.

2. The catalyst of the present invention has stable properties, is safe to use, and has high efficiency in catalytic hydrogen release.

3. The catalytic hydrogen release system of the present invention is a heterogeneous catalytic reaction, which facilitates the recovery and utilization of the catalyst.

4. The raw materials required for the preparation of the cheap metal phosphide used in the present invention are cheap and the preparation method is simple.

Description of drawings

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

FIG. 1 shows a transmission electron microscope (TEM) image of nickel phosphide prepared in Example 1 of the present invention.

Figure 2 shows the powder diffraction (XRD) spectrum of the nickel phosphide prepared in Example 1 of the present invention before participating in the reaction.

Fig. 3 shows the energy spectrum (EDX) diagram of nickel phosphide prepared in Example 1 of the present invention under a scanning electron microscope (SEM).

Fig. 4 shows the curve of hydrogen release volume changing with time in the catalytic hydrolysis process of the system of Example 9 of the present invention (fixing the concentration of ammonia borane, changing the amount of catalyst).

Fig. 5 shows the curve of ln(rate) changing with ln[Ni ₂ P] during the catalytic hydrolysis process of the system of Example 9 of the present invention.

Fig. 6 shows the curve of hydrogen release volume changing with time in the process of catalytic hydrolysis of the system of Example 9 of the present invention (fixing the amount of catalyst, changing the concentration of ammonia borane).

Fig. 7 shows the curve of ln(rate) changing with ln[AB] in the system of Example 9 of the present invention during the catalytic hydrolysis process.

Fig. 8 shows the curve of hydrogen release volume changing with time in the catalytic hydrolysis process of the system of Example 9 of the present invention (fixed catalyst amount and ammonia borane concentration).

Fig. 9 shows the curve of lnTOF changing with the reciprocal of temperature during the catalytic hydrolysis process of the system of Example 9 of the present invention.

Fig. 10 shows the curve of hydrogen release volume changing with time during the catalytic hydrolysis process of the catalyst prepared in Example 1 of the present invention.

Fig. 11 shows the powder diffraction (XRD) spectrum of nickel phosphide prepared in Example 1 of the present invention after participating in the reaction.

Detailed ways

In order to illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments and accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present invention.

Example 1

A kind of nanometer metal phosphide catalyst nickel phosphide (Ni ₂ P), its preparation method is as follows:

1) Preparation of catalyst precursor

In a round-bottomed flask, 1000.0 mg of nickel chloride hexahydrate, 250 mg of sodium citrate, 45 mL of distilled water, and 2.8 g of sodium hydroxide were added, and the mixture was stirred at room temperature for 40 min to obtain a green colloid. The green colloid in the mixture was collected by centrifugation, and after washing the green colloid with a large amount of distilled water, it was fully dried at 373K to remove water to obtain the precursor nickel hydroxide of the catalyst.

2) Reduction of precursor by gas-solid reaction method

Thoroughly grind and mix 200mg nickel hydroxide and 1000mg sodium hypophosphite to obtain light green powder. Under argon flow, the green powder was placed in a porcelain boat of a tube furnace, heated slowly from room temperature to 543K, and maintained at the heating temperature for 4 h. After the reaction, slowly cool down to room temperature, and wash the product with a large amount of distilled water and dilute hydrochloric acid to fully remove the inorganic salt and nickel oxide inside to obtain a nano-nickel phosphide (Ni ₂ P) catalyst.

FIG. 1 is a transmission electron microscope (TEM) image of nickel phosphide prepared in Example 1 of the present invention. It can be seen from the figure that the particle size of the catalyst does not exceed 20nm. Fig. 2 is a powder diffraction (XRD) spectrogram of the nickel phosphide prepared in Example 1 of the present invention before participating in the reaction. The four obvious diffraction peaks in the figure are located at 40.7°, 44.6°, 47.4°, and 54.2° respectively, corresponding to the powder diffraction standard card number 03-0953. Fig. 3 is an energy spectrum (EDX) diagram under a scanning electron microscope (SEM) of nickel phosphide prepared in Example 1 of the present invention. The figure shows that the ratio of nickel to phosphorus is about 2:1.

Example 2

A kind of nanometer metal phosphide catalyst nickel phosphide (Ni ₂ P), its preparation method is as follows:

1) Preparation of catalyst precursor

In a round bottom flask, 200.0 mg of nickel sulfate, 150 mg of sodium citrate, 135 mL of distilled water, and 0.6 g of sodium hydroxide were added, and the mixture was stirred at room temperature for 10 min to obtain a green colloidal precipitate. The green colloidal precipitate in the mixture was collected by centrifugation, and after washing the green colloidal precipitate with a large amount of distilled water, it was fully dried at 353K to remove water to obtain the precursor nickel hydroxide of the catalyst.

2) Reduction of precursor by gas-solid reaction method

50mg of nickel hydroxide and 250mg of sodium hypophosphite were fully ground and mixed to obtain light green powder. Under argon flow, the green powder was placed in a porcelain boat of a tube furnace, slowly heated from room temperature to 573K, and maintained at the heating temperature for 1 h. After the reaction, slowly cool down to room temperature, and wash the product with a large amount of distilled water and dilute hydrochloric acid to fully remove the inorganic salt and nickel oxide inside to obtain a nano-nickel phosphide (Ni ₂ P) catalyst.

Example 3

A kind of nano metal phosphide catalyst iron phosphide (FeP), its preparation method is as follows:

50mg of anhydrous ferric trichloride and 280mg of sodium hypophosphite were fully ground and mixed to obtain brown yellow powder. Under argon flow, the powder was placed in a porcelain boat of a tube furnace, heated slowly from room temperature to 623K, and maintained at the heating temperature for 1 h. After the reaction is completed, slowly cool down to room temperature, and wash the product with a large amount of distilled water and dilute hydrochloric acid to fully remove the inorganic salts inside, that is, to obtain a nanometer iron phosphide (FeP) catalyst.

Example 4

A kind of nano metal phosphide catalyst cobalt phosphide (CoP), its preparation method is as follows:

1) Preparation of catalyst precursor

In a round bottom flask, 1000.0 mg cobalt nitrate hexahydrate, 250 mg sodium citrate, 500 mL distilled water, 1.0 g sodium hydroxide were added, and the mixture was stirred at room temperature for 120 min to obtain a dark purple colloid. The purple colloid in the mixture was collected by centrifugation, and after washing the purple colloid with a large amount of distilled water, it was fully dried at 353K to remove water to obtain cobalt hydroxide, a precursor of the catalyst.

2) Reduction of precursor by gas-solid reaction method

200mg of cobalt hydroxide and 1200mg of sodium hypophosphite were fully ground and mixed to obtain purple black powder. Under argon flow, the powder was placed in a porcelain boat of a tube furnace, heated slowly from room temperature to 573K, and maintained at the heating temperature for 2 h. After the reaction is completed, slowly cool to room temperature, and wash the product with a large amount of distilled water and dilute hydrochloric acid to fully remove the inorganic salt and cobalt oxide inside to obtain a nano-cobalt phosphide (CoP) catalyst.

Example 5

A kind of nano metal phosphide catalyst cobalt phosphide (Cu ₃ P), its preparation method is as follows:

1) Preparation of catalyst precursor

In a round bottom flask, add 400.0 mg copper chloride dihydrate, 100 mg sodium citrate, 200 mL distilled water, 0.9 g sodium hydroxide, and stir the mixture at room temperature for 1 min to obtain a blue suspension. The blue solid in the mixture was collected by centrifugation, and after washing the blue solid with a large amount of distilled water, it was fully dried at 373K to remove water to obtain copper hydroxide, a precursor of the catalyst.

2) Reduction of precursor by gas-solid reaction method

100mg of copper hydroxide and 500mg of sodium hypophosphite were thoroughly ground and mixed to obtain a blue powder. Under argon flow, the powder was placed in a porcelain boat in a tube furnace, heated slowly from room temperature to 623K, and maintained at the heating temperature for 2 h. After the reaction, slowly cool down to room temperature, and wash the product with a large amount of distilled water and dilute hydrochloric acid to fully remove the inorganic salt and copper oxide inside, that is, to obtain a nano copper phosphide (Cu ₃ P) catalyst.

Example 6

A kind of nano metal phosphide catalyst nickel phosphide (Ni ₁₂ P ₅ ), its preparation method is as follows:

Dissolve 2.5g of nickel acetate in a mixed solvent of 80mL of ethanol and water (1:1 by volume), then add 100mg of hexamethylenetetramine, and then add 1.75g of red phosphorus. The above mixture was poured into a 100mL reaction kettle, heated to 443K and maintained at this temperature for 12h. After cooling to room temperature, the precipitate was collected by centrifugation, washed with a large amount of distilled water several times, and dried to obtain Ni ₁₂ P ₅ .

Example 7

A kind of nanometer metal phosphide catalyst nickel phosphide (Ni ₂ P), its preparation method is as follows:

Dissolve 950mg of nickel chloride in 40mL of distilled water, then add 200mg of cetyltrimethylammonium bromide, 1.1g of sodium acetate and 0.64g of red phosphorus. The above mixture was poured into a 50mL reaction kettle, heated to 433K and maintained at this temperature for 8h. After cooling to room temperature, the precipitate was collected by centrifugation, washed with a large amount of distilled water several times, and dried to remove water to obtain Ni ₂ P.

Example 8

A kind of nano metal phosphide catalyst cobalt phosphide (Co ₂ P), its preparation method is as follows:

Dissolve 952mg of cobalt chloride in 60mL of distilled water, then add 200mg of cetyltrimethylammonium bromide and 20mL of ethylene glycol. Pour the above mixture into a 100mL reactor, then add 1.3g of white phosphorus, heat to 453K after sealing and keep the temperature for 20h. After cooling to room temperature, the precipitate was collected by centrifugation, washed with a large amount of distilled water several times, and dried to remove water to obtain Co ₂ P.

Example 9

An ammonia borane (AB) hydrolysis hydrogenation system comprising nickel phosphide (Ni ₂ P) prepared in Example 1: the system includes nickel phosphide and ammonia borane aqueous solution. The research on the water-interpreted hydrogen behavior of this system is as follows:

A 10mL two-caliber round-bottomed flask equipped with a magnetic stirrer is fixed in a constant temperature water bath with adjustable temperature, and then the nickel phosphide catalyst prepared in Example 1 is added to the reaction flask. Finally, use a rubber stopper to seal the outlet at one end with a larger caliber, and connect the other end of the reaction bottle to a measuring gas tube with a precision scale using a rubber tube. After confirming that there is no gas exchange between the system and the surrounding environment, use a syringe to quickly inject a certain volume of AB aqueous solution into the reaction bottle through the rubber stopper. After the injection, immediately press the stopwatch to start timing. The generated hydrogen was detected by Shimadzu DC-14C gas chromatograph, which used a 0.5nm molecular sieve column (3m×2mm), thermal conductivity cell detector (TCD), and the carrier gas was argon.

To study the impact of the amount of catalyst in the system on the rate of catalytic hydrolysis, including the following steps:

At 298K, the molar ratios of Ni ₂ P and AB are controlled to be 0.02, 0.05, 0.08, 0.12 and 0.16 respectively. By calculation, the masses of Ni ₂ P nanoparticles required are 4.8mg, 12.2mg, 19.1mg and 28.8mg respectively. and 38.4mg. 5 parts of catalyst samples with different amounts were added to 5 parts of AB aqueous solution (50 mg dissolved in 5 mL of distilled water) of the same volume and concentration, and the volume of hydrogen collected by each burette at different times was recorded. The time required to release the hydrogen gas is 8.65 min, 2.98 min, 2.52 min, 1.25 min and 1.02 min, respectively, and the curves are plotted by hydrogen volume and time, as shown in Figure 4. Through the part of each curve close to the straight line, the catalytic hydrogen release rates under different catalyst amounts were calculated, and the corresponding TOF values were calculated to be 26.93, 33.75, 35.26, 40.44 and 39.04molH ₂ ·(molNi ₂ P) ^-1 ·min ^-1 . Take the natural logarithm of the 5 catalytic hydrogen release rates and the 5 Ni ₂ P nanoparticle concentrations to obtain 5 ln(rate) and 5 ln[Ni ₂ P], and use ln(rate) to ln[Ni ₂ P] The curve is shown in Figure 5, and the slope of the curve is 1.19, which indicates that the catalytic hydrolysis reaction is a first-order reaction for the catalyst. Therefore, in this system, the influence of the amount of catalyst on the rate of catalytic hydrolysis is: as the amount of catalyst increases, the rate of hydrolysis of ammonia borane increases.

Research the impact of the amount of ammonia borane on the rate of catalytic hydrolysis in this system, comprising the following steps:

At 298K, the masses of AB dissolved in 5 parts of 5mL water are 25mg, 35mg, 45mg, 55mg and 65mg respectively. These 5 parts of AB solutions with different concentrations were respectively added to 5 reaction flasks containing 8 mg of Ni ₂ P. Record the volume of hydrogen collected by each burette at different times, and plot the hydrogen volume versus time as curves, as shown in Figure 6. Calculate the catalytic hydrogen release rate under different amounts of AB through the part of each curve close to the straight line, and then take the natural logarithm of the five catalytic hydrogen release rates to obtain 5 ln(rate), and use ln(rate) to ln[ AB] make a curve, as shown in Figure 7, the slope of the curve is 0.495, showing that this catalytic hydrolysis reaction is a 0.5 order reaction for AB. Therefore, in this system, the influence of the amount of ammonia borane on the rate of catalytic hydrolysis is: as the amount of ammonia borane increases, the rate of hydrolysis increases slowly.

To study the influence of reaction temperature on catalytic hydrolysis rate in this system, including the following steps:

The mass of fixed Ni ₂ P is 8 mg, and 5 parts of the same mass of Ni ₂ P are added to 5 parts of AB aqueous solution (50 mg dissolved in 5 mL of distilled water) at different temperatures but with the same volume and concentration, and the temperatures are 273K, 283K, 301K, 313K and 323K. Record the volume of hydrogen collected by each burette at different times. The time required to release the hydrogen is 46.4min, 20.1min, 7.2min, 4.03min and 2.8min respectively, and the hydrogen volume is plotted against the time, as shown in Figure 8, and the difference is calculated by the part of each curve close to the straight line Catalytic hydrogen release rate under the amount of catalyst, further calculated the corresponding TOF value, they are 4.08, 8.05, 29.94, 54.17 and 78.75molH ₂ ·(molNi ₂ P) ^-1 ·min ^-1 . Take the natural logarithm for the 5 catalytic TOF (transformation frequency) values to obtain 5 lnTOFs. Finally, according to the Arrhenius formula, draw a curve with the reciprocal of lnTOF versus temperature, as shown in Figure 9. According to the slope of the curve, the reaction in the system is calculated. The activation energy is about 44.60KJ/mol. In this system, the influence of the reaction temperature on the catalytic hydrolysis rate is: as the temperature increases, the hydrolysis rate of ammonia borane increases.

To study the recycling situation of the catalyst in the system, including the following steps:

Recover the catalyst used in the above case. At 298K, take the recovered catalyst (8mg) and add it to the AB aqueous solution (50mg dissolved in 5mL distilled water), and record the volume of hydrogen collected by the trachea at different times. After the recovered Ni ₂ P catalyzed AB aqueous solution is hydrolyzed to release hydrogen, the washed catalyst is recovered again to be put into the next cycle. After reusing the above-recovered catalyst 6 times, record the volume of hydrogen and the corresponding time during each reuse. Make a curve with each hydrogen volume versus time and calculate each TOF value, as shown in FIG. 10 . It can be concluded from the results shown in Figure 10 that the recovered nickel phosphide (Ni ₂ P) catalyst still maintains a high activity for catalyzing the hydrolysis of ammonia borane. Before using the recovered catalyst, a powder diffraction (XRD) spectrum was made on the recovered catalyst, as shown in FIG. 11 . The four obvious diffraction peaks in Figure 11 are located at 40.7°, 44.6°, 47.4°, and 54.2° respectively, corresponding to the powder diffraction standard card number 03-0953. From the comparison of Figure 11 and Figure 2, it can be seen that the nickel phosphide (Ni ₂ P) catalyst has no qualitative change before and after the catalytic reaction, that is, the catalyst can exist stably in an oxygen and acid environment.

Example 10

A hydrazine hydrate hydrolysis hydrogenation system comprising nickel phosphide (Ni ₂ P) prepared in Example 1: the system comprises nickel phosphide and an aqueous solution of hydrazine hydrate. The research on the behavior of hydrogen interpretation by water in this system is the same as in Example 9, and the experimental results obtained are similar to those in Example 9.

Example 11

A hydrazine hydrate hydrolysis hydrogenation system comprising iron phosphide (FeP) prepared in Example 3: the system includes iron phosphide (FeP) and an aqueous solution of hydrazine hydrate. The research on the behavior of hydrogen interpretation by water in this system is the same as in Example 9, and the experimental results obtained are similar to those in Example 9.

Example 12

An ammonia borane hydrolysis hydrogenation system comprising cobalt phosphide (CoP) prepared in Example 4: the system includes cobalt phosphide (CoP) and ammonia borane aqueous solution. The research on the hydrogen-interpreting behavior of the system is the same as in Example 9, and the experimental results obtained are similar to those in Example 9.

Example 13

An ammonia borane hydrolysis system containing copper phosphide (Cu ₃ P) prepared in Example 5: the system includes copper phosphide (Cu ₃ P) and an aqueous solution of ammonia borane. The research on the behavior of hydrogen interpretation by water in this system is the same as in Example 9, and the experimental results obtained are similar to those in Example 9.

Example 14

An ammonia borane hydrolysis hydrogen system comprising nickel phosphide (Ni ₁₂ P ₅ ) prepared in Example 6: the system includes nickel phosphide (Ni ₁₂ P ₅ ) and ammonia borane aqueous solution. The research on the behavior of hydrogen interpretation by water in this system is the same as in Example 9, and the experimental results obtained are similar to those in Example 9.

Example 15

An ammonia borane aqueous dehydrogenation system comprising cobalt phosphide (Co _{2 P) prepared in Example 8: the system includes cobalt phosphide (Co 2 P} ) and ammonia borane aqueous solution. The research on the behavior of hydrogen interpretation by water in this system is the same as in Example 9, and the experimental results obtained are similar to those in Example 9.

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those of ordinary skill in the art can also make It is impossible to exhaustively list all the implementation modes here, and any obvious changes or changes derived from the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims (10)

1. one kind contains nano metal phosphide M _xp _ythe ammonia borine of catalyst or hydrazine hydrate catalytic water explain hydrogen system, it is characterized in that: described system comprises nano metal phosphide catalyst, ammonia borine or hydrazine hydrate, Yi Jishui; Described nano metal phosphide catalyst can be expressed as M _xp _y, wherein M is Fe, Co, Ni or Cu, 1≤x≤20,1≤y≤10.

2. one according to claim 1 contains nano metal phosphide M _xp _ythe ammonia borine of catalyst or hydrazine hydrate catalytic water explain hydrogen system, it is characterized in that: described nano metal phosphide catalyst is non-water-soluble.

3. one according to claim 1 contains nano metal phosphide M _xp _ythe ammonia borine of catalyst or hydrazine hydrate catalytic water explain hydrogen system, it is characterized in that: the size of described nano metal phosphide catalyst is no more than 100nm.

4. one according to claim 1 contains nano metal phosphide M _xp _ythe ammonia borine of catalyst or hydrazine hydrate catalytic water explain hydrogen system, it is characterized in that: the preparation method of described nano metal phosphide catalyst comprises the steps:

1) slaine, natrium citricum, alkali and water are placed in container to mix, stir, obtain colloid; This colloid of separated and collected, washing, dry, obtain metal hydroxides precursor;

2) by step 1) the metal hydroxides precursor that obtains and the abundant mixed grinding of sodium hypophosphite, calcine under an inert atmosphere, after being cooled to room temperature, with distilled water and watery hydrochloric acid washing, namely obtain nano metal phosphide catalyst.

5. one according to claim 4 contains nano metal phosphide M _xp _ythe ammonia borine of catalyst or hydrazine hydrate catalytic water explain hydrogen system, it is characterized in that: step 1) in, the mass ratio of described slaine and natrium citricum is 1:0.25-0.75; The time of stirring is 1-300min; Dry temperature is 323-423K; Described slaine is selected from molysite, cobalt salt, nickel salt or mantoquita; Described alkali is selected from NaOH, potassium hydroxide or ammoniacal liquor; Step 2) in, the mass ratio of described metal hydroxides precursor and sodium hypophosphite is 1:2-10; Described inert atmosphere is argon gas; The temperature of calcining is 523-673K; The time of calcining is 0.5-6h.

6. one according to claim 5 contains nano metal phosphide M _xp _ythe ammonia borine of catalyst or hydrazine hydrate catalytic water explain hydrogen system, it is characterized in that: described molysite is selected from ferric trichloride, ferric nitrate or ferrous sulfate; Described cobalt salt is selected from cobalt chloride, cobalt nitrate or cobalt acetate; Described nickel salt is selected from nickel chloride, nickelous sulfate, nickel nitrate, nickel acetate or nickel oxalate; Described mantoquita is selected from copper chloride or copper sulphate.

7. one according to claim 1 contains nano metal phosphide M _xp _ythe ammonia borine of catalyst or hydrazine hydrate catalytic water explain hydrogen system, it is characterized in that: the preparation method of described nano metal phosphide catalyst can also be:

By the slaine except nitrate and the abundant mixed grinding of sodium hypophosphite, calcine under an inert atmosphere, after being cooled to room temperature, with distilled water and watery hydrochloric acid washing, namely obtain nano metal phosphide catalyst.

8. one according to claim 1 contains nano metal phosphide M _xp _ythe ammonia borine of catalyst or hydrazine hydrate catalytic water explain hydrogen system, it is characterized in that: the preparation method of described nano metal phosphide catalyst can also be:

Slaine is dissolved in the mixed solvent that distilled water or distilled water and alcohol mixes with arbitrary proportion, then adds red phosphorus or white phosphorus, obtain mixed system, described mixed system is carried out hydro-thermal reaction; After being cooled to room temperature, centrifugal collecting precipitation also uses distilled water washing precipitation, namely obtains nano metal phosphide catalyst.

9. one according to claim 8 contains nano metal phosphide M _xp _ythe ammonia borine of catalyst or hydrazine hydrate catalytic water explain hydrogen system, it is characterized in that: can also add sodium acetate and/or hexa and/or surfactant in described mixed system; Described surfactant be selected from polyvinylpyrrolidone, acrylamide, neopelex and softex kw one or more; Described alcohol be selected from methyl alcohol, ethanol, ethylene glycol, glycerine and polyethylene glycol one or more; The mol ratio of described phosphorus and metal is 1:1-30; The temperature of described hydro-thermal reaction is 403-473K, and the time of hydro-thermal reaction is 6-30h.

10. as described in as arbitrary in claim 1-9 containing nano metal phosphide M _xp _ythe ammonia borine of catalyst or hydrazine hydrate catalytic water explain that hydrogen system explains the application in hydrogen field in catalytic water.