阅读说明：本技术 一种含Bi和Mo的镁基粉体复合制氢材料及其制备方法和应用 (Bi and Mo-containing magnesium-based powder composite hydrogen production material and preparation method and application thereof ) 是由 孙立贤 林杰 徐芬 王涛 廖鹿敏 周天昊 张焕芝 邹勇进 曹子龙 刘博涛 于 2021-05-07 设计创作，主要内容包括：本发明公开了一种含Bi和Mo的镁基粉体复合制氢材料,将可溶性Bi盐与可溶性Mo酸盐通过水热法制备得Bi/Mo化合物,再将原料Mg粉与Bi/Mo化合物进行球磨混合,所述Bi/Mo化合物必须同时满足以下两个特点,一是纳米级晶体,二是在球磨过程中,含Bi化合物纳米级晶体不与Mg粉反应,且均匀附着于Mg粉上；所述Bi/Mo化合物为Bi-(2)MoO-(6),Bi/Mo化合物的尺寸为1-5μm,Bi/Mo化合物由尺寸为100-200 nm的纳米级晶体组成。其制备方法包括以下步骤：1)含Bi化合物的制备；2)含Bi和Mo的镁基粉体复合制氢材料的制备。作为水解制氢材料的应用,反应产氢量为801.4-859.2 mLg～(-1),产氢率可达91.9-98.9%,表观活化能为34-35 KJ·mol～(-1)。本发明具有以下优点：纳米级颗粒均匀附着于Mg颗粒表面,提供活性位点；具有良好的抗氧化性能。(The invention discloses a magnesium-based powder composite hydrogen production material containing Bi and Mo, which is characterized in that a Bi/Mo compound is prepared from soluble Bi salt and soluble Mo acid salt by a hydrothermal method, and then raw material Mg powder and the Bi/Mo compound are subjected to ball milling and mixing, wherein the Bi/Mo compound must simultaneously meet the following two characteristics, namely a nano-scale crystal, and the Bi-containing compound nano-scale crystal does not react with the Mg powder and is uniformly attached to the Mg powder in the ball milling process; the Bi/Mo compound is Bi 2 MoO 6 The size of the Bi/Mo compound is 1-5 μm, the size of the Bi/Mo compound is 100-200nmAnd (3) nano-scale crystal composition. The preparation method comprises the following steps: 1) preparing a Bi-containing compound; 2) preparing the magnesium-based powder composite hydrogen production material containing Bi and Mo. The hydrogen production amount of the hydrolysis hydrogen production material is 801.4-859.2 mLg ‑1 The hydrogen production rate can reach 91.9-98.9%, and the apparent activation energy is 34-35 KJ.mol ‑1 . The invention has the following advantages: the nanoscale particles are uniformly attached to the surface of the Mg particles to provide active sites; has good oxidation resistance.)

1. A magnesium-based powder composite hydrogen production material containing Bi and Mo is characterized in that: the preparation method comprises the steps of preparing a Bi/Mo compound from soluble Bi salt and soluble Mo acid salt by a hydrothermal method, and ball-milling and mixing raw material Mg powder and the Bi/Mo compound, wherein the Bi/Mo compound has the following two characteristics that firstly, the Bi/Mo compound is a nano-scale crystal, and secondly, the Bi-containing compound nano-scale crystal does not react with Mg powder and is uniformly attached to the Mg powder in the ball-milling process.

2. The Bi and Mo containing magnesium-based powder composite hydrogen production material of claim 1, which is characterized in that: the Bi/Mo compound is Bi₂MoO₆The size of the Bi/Mo compound is 1 to 5 μm, and the Bi/Mo compound is composed of nanoscale crystals having a size of 100-200 nm.

3. The preparation method of the Bi and Mo containing magnesium-based powder composite hydrogen production material according to claim 1, which is characterized by comprising the following steps:

step 1) preparing a Bi-containing compound, dissolving soluble Bi salt and soluble Mo acid salt in water according to a certain substance quantity ratio, carrying out hydrothermal reaction under certain conditions, and filtering and washing the obtained product to obtain a micron-sized Bi/Mo compound crystal consisting of nano-sized Bi/Mo compound crystals;

and 2) preparing the Bi and Mo-containing magnesium-based powder composite hydrogen production material, namely performing ball milling on the micron-sized Bi/Mo compound particles obtained in the step 1 and Mg powder according to a certain mass ratio under a protective gas condition under a certain condition to obtain the uniformly mixed Bi and Mo-containing magnesium-based powder composite hydrogen production material.

4. The production method according to claim 3, characterized in that: the soluble Bi salt in the step 1 is Bi (NO)₃)₃·5H₂O, soluble Mo acid salt is Na₂MoO₄·2H₂And O, wherein the mass ratio of the soluble Bi salt and the soluble Mo acid salt in the step 1 is 2: 1.

5. The production method according to claim 3, characterized in that: the hydrothermal reaction conditions in the step 1) are that the temperature of the hydrothermal reaction is 160-200 ℃, the time of the hydrothermal reaction is 16-24h, the size of the nano Bi/Mo compound crystal is 100-200nm, and the size of the micro Bi/Mo compound crystal is 1-5 μm.

6. The production method according to claim 3, characterized in that: the ball milling conditions in the step 2) are that the ball-material ratio of the ball milling is 20:1, and the rotating speed of the ball milling is 150-^-1The ball milling time is 15-120 min.

7. The application of the Bi and Mo containing magnesium-based powder composite hydrogen production material as a hydrolysis hydrogen production material according to claim 1 is characterized in that: the hydrogen production amount of the magnesium-based powder composite hydrogen production material containing Bi and Mo is 801.4-859.2 mLg after the reaction of the magnesium-based powder composite hydrogen production material and 3.5 percent NaCl solution^-1The hydrogen production rate can reach 91.9-98.9%, and the apparent activation energy is 34-35 KJ.mol^-1。

Technical Field

The invention belongs to the technical field of energy, and particularly relates to a Bi and Mo-containing magnesium-based powder composite hydrogen production material, and a preparation method and application thereof.

Background

Among many energy sources, hydrogen energy has been widely paid attention and researched as an ideal secondary energy carrier with the advantages of environmental friendliness, wide sources, high energy density and the like, and the preparation and storage of hydrogen energy have been the key points of hydrogen energy research. The method for preparing hydrogen by using magnesium water reaction is an efficient and clean hydrogen preparation method, and the magnesium-based hydrogen production material has the advantages of high theoretical hydrogen production amount, abundant and easily-obtained reserves, mild reaction conditions, no pollution of products and the like, so that the magnesium-based hydrogen production material has long-term application prospect.

The main preparation method of the current Magnesium-based Hydrogen production material is to adopt a high-energy ball milling method, and the catalyst and Magnesium powder are subjected to physical or chemical reaction through high-energy ball milling to ensure that a compact passivation layer generated by the reaction of Magnesium water cannot or is reduced to hinder the reaction of Magnesium water, for example, the related work (DOI: 10.1039/x0xx00000x, Hydrogen generation moisture of Magnesium with water using Mo, MoO)₂, MoO₃ and MoS₂ as catalysts [J]) To adoptHigh activity is obtained by a compound of Mg powder and Mo in the high-energy ball milling process by using a high-energy ball milling method, the hydrogen production performance of the magnesium-based composite material is improved, and Mg-10 wt% x (x = Mo, MoO) is formed by ball milling₂，MoS₂And MoO₃) When the conditions are that the ball-material ratio is 20:1, the ball milling speed is 1h, the rotation speed is 250rpm, the reaction is carried out for 10min at 25 ℃, the hydrogen production rate of 86.5 percent and the initial maximum hydrogen production rate of 751 mL-min can be obtained by Mg-10wt percent of Mo^-1·g^-1。Mg-10wt％MoO₂Can obtain the hydrogen production rate of 88.0 percent and the initial maximum hydrogen production rate of 1933 mL-min^-1·g^-1。Mg-10wt％MoO₃91.7 percent of hydrogen production rate and 2423 mL-min of initial maximum hydrogen production rate can be obtained^-1·g^-1。Mg-10wt％MoS₂Can obtain the hydrogen production rate of 89.8 percent and the initial maximum hydrogen production rate of 1376 mL-min^-1·g^-1. However, this technique has a problem that the hydrogen conversion rate is low at normal temperature.

However, in this hydrolysis technique, as the hydrolysis reaction proceeds, Mg (OH) is formed₂The dense passivation layer blocks the contact of water with the Mg particles, thereby hindering further reactions, resulting in a large decrease in the kinetics of the hydrolysis reaction. Further, since magnesium metal powder is easily oxidized, an MgO oxide layer easily formed with oxygen in the air may hinder the hydrolysis reaction of water and Mg particles and also may cause a decrease in the hydrolysis reaction kinetics. In addition, because magnesium metal has good soft ductility and poor ball milling performance, the improvement of the hydrolysis performance of the magnesium metal by mechanical methods such as ball milling and the like is difficult, and the improvement of the hydrolysis performance can be started from the direction of reducing or destroying a compact passivation layer of the magnesium metal, the research on the high-efficiency clean hydrogen production material and the optimization of the process of the hydrogen production material have important research and practical significance.

Disclosure of Invention

The invention aims to provide a magnesium-based powder composite hydrogen production material containing Bi and Mo aiming at the defects of the prior art.

In order to reduce the obstruction of a compact passivation layer generated in the hydrolysis process of the material and realize the effect of effectively catalyzing and generating hydrogen, a plurality of active sites are generated on Mg powder in the ball milling process, micron-sized Bi multi-component metal oxide particles composed of nano-scale crystals are selected as raw materials, and the micro-morphology of nano-scale Bi multi-component metal oxide uniformly attached to the Mg powder can be formed;

according to the prior art, the Bi compound has better catalytic performance in the high-energy ball milling process, the multi-component metal oxide has higher catalytic activity than metal or metal oxide, and the multi-component metal oxide has better chemical and physical stability and can be stored in outdoor environment for a long time.

The invention also aims to provide a method for preparing hydrogen by hydrolysis by using the magnesium-based powder composite hydrogen preparation material. The hydrogen production method is efficient and simple, does not need complex equipment and procedures in the preparation process, and is low in cost, safe and environment-friendly.

The technical scheme for realizing the purpose of the invention is as follows:

a magnesium-based powder composite hydrogen production material containing Bi and Mo is prepared by preparing a Bi/Mo compound from soluble Bi salt and soluble Mo acid salt by a hydrothermal method, and then ball-milling and mixing raw material Mg powder and the Bi/Mo compound, wherein the Bi/Mo compound must simultaneously meet the following two characteristics, namely a nano-scale crystal and a Bi-containing compound nano-scale crystal which does not react with Mg powder and is uniformly attached to the Mg powder in the ball-milling process; the Bi-containing compound has 1-5 μm particles with the size of 100-200nm crystal composition.

A preparation method of a magnesium-based powder composite hydrogen production material containing Bi and Mo comprises the following steps:

step 1) preparing a Bi-containing compound, dissolving soluble Bi salt and soluble Mo acid salt in water according to a certain substance quantity ratio, carrying out hydrothermal reaction under certain conditions, and filtering and washing the obtained product to obtain a micron-sized Bi/Mo compound crystal consisting of nano-sized Bi/Mo compound crystals;

the soluble Bi salt in the step 1 is Bi (NO)₃)₃·5H₂O, solubilityMo acid salt is Na₂MoO₄·2H₂O, the mass ratio of the soluble Bi salt and the soluble Mo acid salt in the step 1 is 2: 1;

the conditions of the hydrothermal reaction in the step 1) are that the temperature of the hydrothermal reaction is 160-200 ℃, and the time of the hydrothermal reaction is 16-24 h;

step 2) preparing the Bi and Mo-containing magnesium-based powder composite hydrogen production material, namely performing ball milling on the micron-sized Bi/Mo compound crystal obtained in the step 1 and Mg powder in a certain mass ratio under a protective gas condition under a certain condition to obtain the uniformly mixed Bi and Mo-containing magnesium-based powder composite hydrogen production material;

the ball milling conditions in the step 2) are that the ball-material ratio of the ball milling is 20:1, and the rotating speed of the ball milling is 150-^-1The ball milling time is 15-120 min.

An application of a magnesium-based powder composite hydrogen production material containing Bi and Mo as a hydrolysis hydrogen production material, wherein the magnesium-based powder composite hydrogen production material containing Bi and Mo reacts with 3.5% NaCl solution to produce 801.4-859.2 mLg of hydrogen^-1The hydrogen production rate can reach 91.9-98.9%, and the apparent activation energy is 34-35 KJ.mol^-1。

Bi prepared by a hydrothermal method₂MoO₆Material, Mg-Bi produced by ball milling₂MoO₆XRD analysis of the magnesium-based powder composite hydrogen production material shows that only Mg peak and Bi exist in the magnesium-based powder composite hydrogen production material after ball milling₂MoO₆Peak of (b) indicates Bi in the ball milling process₂MoO₆No decomposition reaction occurred.

To Bi₂MoO₆Mg-Bi composite hydrogen production material Mg-Bi mixed with ball-milled magnesium-based powder₂MoO₆SEM appearance analysis is respectively carried out, and the result shows that Bi prepared by a hydrothermal method₂MoO₆Particles of 1-5 μm consisting of 100-200nm crystals; bi after ball milling process₂MoO₆Uniformly attached to the surface of the Mg powder.

The hydrogen production performance test is carried out on the material of ball-milled magnesium powder of different metal oxides, and the result shows that the multicomponent metal oxide Bi prepared by the hydrothermal method₂MoO₆The ball-milled magnesium-based powder composite hydrogen production material has the best hydrogen production performance.

The ball-milled magnesium-based powder composite hydrogen production material is subjected to hydrogen production performance test at different reaction temperatures, and the apparent activation energy obtained by calculation according to the maximum reaction rate is 34.9KJ & mol^-1. This value is much lower than the apparent activation energy (63.9 KJ. mol) of magnesium reacting with seawater^-1) The magnesium-based powder composite hydrogen production material has excellent reaction activity.

SEM appearance analysis and hydrogen production performance test are respectively carried out on the magnesium-based powder composite hydrogen production material with different ball milling time, and the result shows that the magnesium-based powder composite hydrogen production material with the ball milling time of 30min has smaller size and optimal hydrogen production performance, and the magnesium-based powder composite hydrogen production material increases in size and the hydrogen production performance is reduced along with the increase of the ball milling time.

The hydrogen production performance of the ball-milled magnesium-based powder composite hydrogen production material is tested under different air exposure time, and the hydrogen production performance of the magnesium-based powder composite hydrogen production material is 827.3mL g after the magnesium-based powder composite hydrogen production material is exposed in the air for 21 days^-1The corresponding hydrogen production rate and hydrogen production conversion rate are 210 mL/g^-1min^-1And 95.3%.

The experimental detection result of the hydrogen production performance of the invention is as follows: under the conditions of 3.5 percent NaCl solution and 25 ℃, the unit hydrogen production is 801.4 to 859.2 mL g^-1The hydrogen production rate is 444-activated 756 mL-g^-1·min^-1The conversion rate is 91.9-98.9%.

Mg-Bi₂MoO₆The testing of the hydrogen production performance of the powder composite hydrogen production material adopts a drainage and gas collection method to weigh 0.1 g of Mg-Bi prepared₂MoO₆Compounding the powder with hydrogen producing material; at 25 ℃, 10mL of 3.5% NaCl solution is added, and the generated gas is collected and the hydrogen production performance is measured.

The invention has the following advantages:

1. the preparation method is rapid, simple, energy-saving and environment-friendly;

2. bi prepared by hydrothermal method₂MoO₆The diameter of catalyst particles is small; ball milled nano-scale Bi₂MoO₆Can be uniformly attached to the surface of Mg particles to provide a plurality of reactive sites and improve the reaction rate of magnesium water;

3. prepared Mg-Bi₂MoO₆The powder composite hydrogen production material has good oxidation resistance.

Therefore, the invention has simple manufacturing process, low cost of raw materials, no pollution of products and high hydrogen production efficiency, and can be used as a hydrogen source of a fuel cell.

Description of the drawings:

FIG. 1 shows the Mg-based powder composite hydrogen production material prepared by ball milling in example 1, ball-milled Mg powder, and Bi prepared by hydrothermal method₂MoO₆XRD pattern of (a);

FIG. 2 shows Bi obtained after hydrothermal reaction in step 1 of example 1₂MoO₆SEM picture of (1);

FIG. 3 shows Mg-Bi obtained in step 2 of example 1₂MoO₆SEM picture of powder composite hydrogen production material;

FIG. 4 is a graph showing hydrogen production rate in hydrolysis at 25 ℃ for example 1 and a sample in which magnesium powder and metal oxide were ball-milled at a ratio of 9: 1;

FIG. 5 shows different Bi contents obtained in examples 1 and 2 and comparative examples 5, 6 and 7₂MoO₆Mg-Bi of₂MoO₆The powder composite hydrogen production material has a hydrolysis reaction hydrogen production curve at 25 ℃, namely a hydrogen production quantity curve, a hydrogen production rate curve and a hydrogen production rate curve;

FIG. 6 is an apparent activation energy diagram of the magnesium-based powder composite hydrogen production material prepared in example 2;

FIG. 7 shows Mg-Bi prepared in comparative example 5 and ball-milled for 60min₂MoO₆SEM picture of powder composite hydrogen production material;

FIG. 8 shows Mg-Bi prepared in comparative example 6 and ball-milled for 120min₂MoO₆SEM picture of powder composite hydrogen production material;

FIG. 9 shows example 2 and Mg-Bi exposed to air₂MoO₆The hydrogen production rate curve of the powder composite hydrogen production material hydrolyzed at 25 ℃.

Detailed Description

The invention is further described in detail by the embodiments and the accompanying drawings, but the invention is not limited thereto.

Example 1

A preparation method of a Bi and Mo-containing magnesium-based powder composite hydrogen production material and a hydrogen production performance test comprise the following steps:

step 1) hydrothermal reaction process according to Bi (NO)₃)₃·5H₂O and Na₂MoO₄·2H₂O satisfies the ratio of the amount of substance 2:1, weighing Bi (NO)₃)₃·5H₂O and Na₂MoO₄·2H₂Dissolving O in deionized water, transferring to a reaction kettle for hydrothermal reaction at 180 ℃ for 20h, and washing with deionized water for multiple times to obtain Bi/Mo compound crystal particles;

step 2) ball milling process, under the protection of argon atmosphere, weighing Mg powder and Bi/Mo compound crystals according to the mass ratio of Mg powder to Bi/Mo compound crystals being 9:1, wherein the ball-material ratio is 20:1, and the ball milling speed is 250 r.min^-1And performing ball milling for 30min to obtain the uniformly mixed magnesium-based powder composite hydrogen production material.

In order to prove the respective functions of the hydrothermal process and the ball milling process in the technical scheme, the Bi obtained in the step 1 is subjected to₂MoO₆XRD analysis is carried out on the crystal and the magnesium-based powder composite hydrogen production material obtained in the step 2, and the result is shown in figure 1.

Bi obtained after hydrothermal process₂MoO₆In the particles, only Bi is present₂MoO₆The experimental result shows that Bi is successfully synthesized in the hydrothermal method process₂MoO₆The particles are washed for many times by deionized water, most or all unreacted medicines are removed, namely the high-purity Bi is synthesized by a hydrothermal method₂MoO₆Particles;

in the magnesium-based powder composite hydrogen production material obtained after the ball milling process, only Mg and Bi exist₂MoO₆The experimental results show that no Bi occurs during the ball milling process₂MoO₆Self-decomposition or redox reaction with Mg, i.e. ball milling process only serves to mix Mg and Bi homogeneously₂MoO₆The function of (1);

to demonstrate that during the ball milling process, Bi₂MoO₆The influence on the micro-morphology of the powder composite material on the Bi obtained in the step 1₂MoO₆SEM analysis is carried out on the particles and the magnesium-based powder composite hydrogen production material obtained in the step 2, and the results are shown in figures 2 and 3.

Bi prepared by hydrothermal method₂MoO₆The microstructure of the particles is shown in FIG. 2, Bi₂MoO₆The micron-sized particles are composed of nano-scale crystals;

the microstructure of the magnesium-based powder composite hydrogen production material is shown in figure 3, and Bi₂MoO₆The nano-crystals are uniformly attached to the magnesium powder;

the SEM result is combined with XRD experiment to show that Bi is generated during ball milling₂MoO₆The nano crystal is evenly attached to the magnesium powder, so that the active sites of the material reaction are increased, and the hydrogen production performance of the material is improved.

In order to prove the influence of oxide ball-milled magnesium powder on the hydrogen production performance, a magnesium-based powder material with 10 percent of oxide doping amount is prepared in a comparative example 1, a comparative example 2, a comparative example 3 and a comparative example 4, wherein oxides are respectively MoO₂、MoO₃、Bi₂O₃And (MoO)₃+Bi₂O₃）。

Comparative example 1

A preparation method of Mg-metal oxide powder composite hydrogen production material and a hydrogen production performance test are provided, and the steps which are not particularly described in the specific steps are the same as those in the embodiment 1; the difference lies in that: step 2 weighing 2.7g of Mg powder and 0.3g of MoO₂The obtained magnesium-based powder composite hydrogen production material is named as 90% Mg-10% MoO₂。

Comparative example 2

A preparation method of Mg-metal oxide powder composite hydrogen production material and a hydrogen production performance test are provided, and the steps which are not particularly described in the specific steps are the same as those in the embodiment 1; the difference lies in that: step 2 weighing 2.7g of Mg powder and 0.3g of MoO₃The obtained magnesium-based powder composite hydrogen production material is named as 90% Mg-10% MoO₃。

Comparative example 3

Mg-metal oxide powder composite hydrogen production materialThe preparation method of the material and the hydrogen production performance test are the same as those in the embodiment 1, wherein the steps which are not particularly described in the concrete steps are the same as those in the embodiment 1; the difference lies in that: step 2 weighing 2.7g of Mg powder and 0.3g of Bi₂O₃The obtained magnesium-based powder composite hydrogen production material is named as 90 percent Mg-10 percent Bi₂O₃。

Comparative example 4

A preparation method of Mg-metal oxide powder composite hydrogen production material and a hydrogen production performance test are provided, and the steps which are not particularly described in the specific steps are the same as those in the embodiment 1; the difference lies in that: step 2, weighing 2.7g of Mg powder and 0.15g of MoO₃And 0.15g Bi₂O₃The obtained magnesium-based powder composite hydrogen production material is named as 90% Mg-5% MoO₃-5%Bi₂O₃。

The test results are given in table 1 below.

TABLE 1 Hydrogen production performance of composite hydrogen production material of metal oxide ball-milled magnesium powder and magnesium-based powder in 1800 seconds

As shown in Table 1, the magnesium powder material prepared by ball milling magnesium powder with metal oxide has unsatisfactory hydrogen production performance, and Bi is added in the ball milling₂MoO₆The prepared magnesium-based powder composite hydrogen production material has excellent hydrogen production performance, which indicates that Bi is added by ball milling₂MoO₆Is favorable for improving Mg-Bi₂MoO₆The hydrogen production performance of the powder composite hydrogen production material.

To prove different Bi₂MoO₆The influence of the doping amount on the hydrogen production performance of the magnesium-based powder composite hydrogen production material, and a comparative example 5, a comparative example 6, an example 2 and a comparative example 7 provide Bi preparation₂MoO₆Mg-Bi with doping ratios of 3%, 5%, 7% and 13%, respectively₂MoO₆Powder composite hydrogen production material.

Comparative example 5

Mg-Bi₂MoO₆Preparation method of powder composite hydrogen production material and hydrogen production performance test, and steps and practice not particularly described in specific stepsThe same as in example 1; the difference lies in that: step 2, weighing 2.91g of Mg powder and 0.09g of Bi₂MoO₆The obtained magnesium-based powder composite hydrogen production material is named as 97 percent Mg-3 percent Bi₂MoO₆。

Comparative example 6

Mg-Bi₂MoO₆The preparation method of the powder composite hydrogen production material and the hydrogen production performance test are the same as those in the embodiment 1, wherein the steps are not particularly described; the difference lies in that: step 2 weighing 2.85g of Mg powder and 0.15g of Bi₂MoO₆The obtained magnesium-based powder composite hydrogen production material is named as 95 percent Mg-5 percent Bi₂MoO₆。。

Example 2

Mg-Bi₂MoO₆The preparation method of the powder composite hydrogen production material and the hydrogen production performance test are the same as those in the embodiment 1, wherein the steps are not particularly described; the difference lies in that: step 2 weighing 2.79g of Mg powder and 0.21g of Bi₂MoO₆The obtained magnesium-based powder composite hydrogen production material is named as 93 percent Mg-7 percent Bi₂MoO₆。

Comparative example 7

Mg-Bi₂MoO₆The preparation method of the powder composite hydrogen production material and the hydrogen production performance test are the same as those in the embodiment 1, wherein the steps are not particularly described; the difference lies in that: step 2 weighing 2.61g of Mg powder and 0.39g of Bi₂MoO₆The obtained magnesium-based powder composite hydrogen production material is named as 87 percent Mg-13 percent Bi₂MoO₆。

TABLE 2 different Bi at 25 deg.C₂MoO₆Content of produced Mg-X wt% Bi₂MoO₆Hydrogen production performance of powder composite hydrogen production material

The experimental result shows that the catalyst Bi is increased₂MoO₆The content can effectively increase the reaction rate and enhance the hydrogen production performance, wherein the sample contains 93 percent of Mg and 7 percent of Bi₂MoO₆The hydrogen production performance is optimal, and the hydrogen production amount reaches 857.9mL g^-1The corresponding hydrogen production rate and the hydrogen production conversion rate are 756 mL-g^-1min^-1And 98.8%. The hydrogen production conversion rate of the obtained sample is more than 90% when the catalyst content is 3% to 13%.

In order to prove the reaction kinetics performance of the magnesium-based powder composite hydrogen production material, the magnesium-based powder composite hydrogen production material is reacted with 3.5% NaCl solution at the temperature of 15 ℃, 25 ℃, 35 ℃, 45 ℃ and 55 ℃, the hydrogen production performance of the magnesium-based powder composite hydrogen production material is tested, the activation energy is calculated, and the hydrogen production performance is shown in Table 3.

TABLE 3 93% Mg-7% Bi at various temperatures₂MoO₆Hydrogen production performance of magnesium-based powder composite hydrogen production material

Fitting was performed according to the arrhenitz equation and the experimental data in the table above, and the results are shown in fig. 6. The apparent activation energy of the reaction of the magnesium-based powder composite hydrogen production material and 3.5 percent NaCl solution is 34.9 KJ.mol^-1. This value is much lower than the apparent activation energy (63.9 KJ. mol) of magnesium reacting with seawater^-1) The magnesium-based powder composite hydrogen production material has excellent reaction activity.

To prove the ball milling time vs. Mg-Bi₂MoO₆The influence of the hydrogen production performance of the powder composite hydrogen production material is that Mg-Bi with ball milling time of 15min, 60min and 120min is prepared by a comparative example 8, a comparative example 9 and a comparative example 10₂MoO₆Powder composite hydrogen production material.

Comparative example 8

Mg-Bi₂MoO₆The preparation method of the powder composite hydrogen production material and the hydrogen production performance test are the same as those in the embodiment 1, wherein the steps are not particularly described; the difference lies in that: the ball milling time in the step 2 is 15min, and the obtained magnesium-based powder composite hydrogen production material is named as 93% Mg-7% Bi₂MoO₆-1。

Comparative example 9

Mg-Bi₂MoO₆The preparation method of the powder composite hydrogen production material and the hydrogen production performance test are the same as those in the embodiment 1, wherein the steps are not particularly described; the difference lies in that: the ball milling time in the step 2 is 60min, and the obtained magnesium-based powder composite hydrogen production material is named as 93% Mg-7% Bi₂MoO₆-2。

Comparative example 10

Mg-Bi₂MoO₆The preparation method of the powder composite hydrogen production material and the hydrogen production performance test are the same as those in the embodiment 1, wherein the steps are not particularly described; the difference lies in that: the ball milling time in the step 2 is 120min, and the obtained magnesium-based powder composite hydrogen production material is named as 93% Mg-7% Bi₂MoO₆-3。

TABLE 4 93% Mg-7% Bi obtained at 25 ℃ for different ball milling times₂MoO₆Hydrogen production performance of powder composite hydrogen production material

Mg-Bi prepared by different ball milling time in figures 3, 7 and 8₂MoO₆The SEM topography of the powder composite hydrogen production material can observe that the sizes of sample particles subjected to ball milling for 60min and 120min are far larger than those of sample particles subjected to ball milling for 30min, because the magnesium is softer, the magnesium powder is subjected to cold welding due to overlong ball milling time, and the hydrogen production performance of the samples subjected to ball milling for 60min and 120min is poor.

The experimental result shows that when the ball milling time is 30min, 93 percent of Mg and 7 percent of Bi₂MoO₆The powder hydrogen production material has the best hydrogen production performance, and the hydrogen production amount reaches 857.9mL g^-1The corresponding hydrogen production rate and the hydrogen production conversion rate are 756 mL-g^-1min^-1And 98.8%. The ball milling time is 15-120min, and the hydrogen production conversion rate of the obtained sample is over 80 percent.

To prove the Mg-Bi of the present invention₂MoO₆Oxidation resistance of powder composite Hydrogen production Material Mg-Bi prepared by example 3, example 4, and example 5 for 7 days, 14 days, and 21 days of air exposure₂MoO₆Powder composite hydrogen production material.

Example 3

Mg-Bi₂MoO₆The preparation method of the powder composite hydrogen production material and the hydrogen production performance test are the same as those in the embodiment 1, wherein the steps are not particularly described; the difference lies in that: the magnesium-based powder composite hydrogen production material obtained after ball milling is exposed in the air for 7 days and is named as 93 percent Mg-7 percent Bi₂MoO₆-7D。

Example 4

Mg-Bi₂MoO₆The preparation method of the powder composite hydrogen production material and the hydrogen production performance test are the same as those in the embodiment 1, wherein the steps are not particularly described; the difference lies in that: the magnesium-based powder composite hydrogen production material obtained after ball milling is exposed to the air for 14 days and is named as 93 percent Mg-7 percent Bi₂MoO₆-14D。

Example 5

Mg-Bi₂MoO₆The preparation method of the powder composite hydrogen production material and the hydrogen production performance test are the same as those in the embodiment 1, wherein the steps are not particularly described; the difference lies in that: the magnesium-based powder composite hydrogen production material obtained after ball milling is exposed in the air for 21 days and is named as 93 percent Mg-7 percent Bi₂MoO₆-21D。

The results of the experiments show that 93% Mg-7% Bi after 21 days of exposure to air₂MoO₆The hydrogen production performance of the powder hydrogen production material is 827.3 mL/g^-1The corresponding hydrogen production rate and hydrogen production conversion rate are 210 mL/g^-1min^-1And 95.3%. Has good oxidation resistance.