Metal-based nano catalytic particle as well as preparation method and application thereof

Abstract

The invention relates to a metal-based nano catalytic particle as well as a preparation method and application thereof. The metal-based nano catalytic particle is prepared by contacting a mixed gas with a magnesium-nickel-based alloy and a hydride thereof and then carrying out a gas-solid reaction, the mixed gas comprises reaction gas and protective gas, and the reaction gas at least comprises one of oxygen and water vapor. Compared with the prior art, the preparation method of the metal-based nano catalytic particles has the advantages of being simple and practical in process, low in cost, suitable for large-scale production and the like. In addition, when the metal-based nano catalytic particles prepared by the method are used for regulating and controlling the reversible hydrogen storage performance of the magnesium-nickel-based alloy hydride, the hydride system has the advantages of high reaction activity, high reaction rate, high hydrogen storage capacity retention rate, few storage environment limiting conditions and the like.

Description

Technical Field

[0001] The present invention relates to the technical fields of nanomaterials and solid-state hydrogen storage, and in particular to a metal-based nano-catalytic particle, a preparation method thereof, and an application thereof. Background Art

[0002] Developing new clean energy to enrich the existing energy system is an inevitable requirement for the development of an environmentally friendly and sustainable society. As a typical clean energy, hydrogen energy has received extensive attention. In the hydrogen energy utilization system, the storage and transportation of hydrogen are key technical problems. Light metal magnesium is a hydrogen storage material with a high hydrogen storage capacity (mass hydrogen storage density of 7.6 wt.%, volume hydrogen storage density of 110 kg / m 3 ), recyclability, and low price. However, its actual dehydrogenation temperature is relatively high (≥350 °C) and the rate is slow, which severely restricts the large-scale application of magnesium-based hydrogen storage materials. Therefore, how to improve the hydrogen absorption and desorption performance of magnesium-based hydrogen storage materials is one of the current research hotspots.

[0003] Adding a catalyst is one of the most direct and effective strategies to improve the reaction kinetics of magnesium-based hydrogen storage materials. Introducing a catalyst into magnesium-based hydrides can serve as both an adsorption and dissociation site for hydrogen and a reaction activity and dissociation site, etc. Among them, metals and their compounds are a type of catalyst with good catalytic effects. Currently, for magnesium-nickel-based alloy hydrides in magnesium-based hydrides, Lin et al. (Frontiers in Chemistry, 2020, 293) added different proportions of CeH 2.73 / CeO2 mixed catalyst to Mg2NiH4 by ball milling, and found that the peak temperature of the thermal decomposition of the sample increased to 267 °C, only 17 °C lower than that of the sample without adding a catalyst. Zhang et al. (Materials Today Communications, 2023, 103217) added 10 wt.% of M (M is one of Zr, Ti, and V) to Mg-Ce-Y-Ni by ball milling. Among them, the sample of Mg-Ce-Y-Ni + 10 wt.% Zr had the lowest peak temperature of the thermal decomposition of the sample (334.3 °C). Zhang and Si et al. (Dalton Transactions, 2018, 47, p8418-8426; Progress in Natural Science: Materials International, 2018, 28, p164-169) introduced Ti, V, Fe, and Si into Mg2Ni. After ball milling, Mg2Ni 0.88 Ti 0.12 H4 had the lowest peak temperature of the thermal decomposition of the sample (262 °C). In addition, this sample needed 60 minutes to be completely dehydrogenated when dehydrogenating for the first time at 260 °C.

[0004] Therefore, the hydrogen absorption and desorption performance of the magnesium-nickel-based alloy hydride still needs to be further improved. Summary of the Invention

[0005] The purpose of the present invention is to provide a metal-based nano-catalytic particle, a preparation method thereof and an application thereof, which catalytically regulate the reversible hydrogen absorption and desorption of magnesium-nickel-based hydride.

[0006] The purpose of the present invention can be achieved by the following technical solutions: a preparation method of a metal-based nano-catalytic particle, in which a gas-solid reaction occurs after a mixed gas contacts a magnesium-nickel-based alloy and its hydride to prepare the metal-based nano-catalytic particle;

[0007] The mixed gas includes a reaction gas and a protective gas, and the reaction gas includes at least one of oxygen and water vapor.

[0008] Preferably, the chemical formula of the magnesium-nickel-based alloy and its hydride is Mg a Ni b TM c H x ;

[0009] Among them, the atomic ratio of each component is a:b:c, where 2 ≤ a:b ≤ 10, 1 ≤ b:c ≤ 19 or 2 ≤ a:b ≤ 10, c = 0; TM is a metal element, including but not limited to cobalt, copper, titanium, iron, chromium, manganese, scandium, yttrium, cerium.

[0010] Further preferably, when the magnesium-nickel-based alloy and its hydride are an alloy, x = 0; when the magnesium-nickel-based alloy and its hydride are a hydride, x > 0.

[0011] Preferably, the particle size of the magnesium-nickel-based alloy and its hydride is 10 - 200 μm.

[0012] Preferably, the volume ratio of the reaction gas to the protective gas is 1:9 - 3:7.

[0013] Preferably, the protective gas is at least one of argon, carbon dioxide, and nitrogen.

[0014] Preferably, the contact mode of the mixed gas with the magnesium-nickel-based alloy and its hydride is fully enclosed sealed storage or continuous purging of the surface of the magnesium-nickel-based alloy and its hydride with the mixed gas.

[0015] Preferably, the pressure of the mixed gas is 0.1 - 5 MPa, the action temperature with the magnesium-nickel-based alloy and its hydride is 10 - 100 °C, and the action time ≤ 100 days.

[0016] A metal-based nano-catalytic particle is prepared by the above preparation method, and the particle size of the metal-based nano-catalytic particle is 3-7 nm.

[0017] Preferably, the metal-based nano-catalytic particle is at least one of the above metals and their compounds, and the particle size is about 5 nm.

[0018] An application of the above metal-based nano-catalytic particle, wherein the metal-based nano-catalytic particle is used as a catalyst for a hydrogen storage material.

[0019] The metal-based nano-catalytic particle of the present invention is in-situ formed on the hydrogen storage material and can be used to catalyze the hydrogen absorption and desorption reaction of the hydrogen storage material.

[0020] Adding a catalyst can improve the reversible hydrogen storage performance of the magnesium-nickel-based alloy hydride to a certain extent. However, introducing a catalyst into the magnesium-nickel-based alloy hydride by methods such as ball milling has the characteristic of uneven catalyst distribution, which may lead to insufficient improvement in the thermal decomposition performance of the hydride upon heating, rapid dehydrogenation only above 250 °C, and rapid decay of the hydrogen storage performance during the activation and hydrogen absorption and desorption cycles of the sample. Therefore, introducing a highly dispersed metal-based nano-catalyst on the surface of the magnesium-nickel-based alloy hydride in the present invention is of great significance for improving the reversible hydrogen storage performance of the hydride.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The metal-based nano-catalytic particle prepared by the method of the present invention has the characteristics of small particle size and uniform dispersion;

[0023] 2. The method for preparing the metal-based nano-catalytic particle of the present invention is simple, practical, low-cost, and suitable for large-scale production;

[0024] 3. The present invention provides a method for preparing metal-based nano-catalytic particles by gas-solid reaction. This method can in-situ form highly dispersed metal-based nano-catalytic particles on the surface of the magnesium-nickel-based alloy hydride at low cost, thereby significantly improving the hydrogen storage performance of the hydride and making it have practical application value;

[0025] 4. When the nano-particles obtained by the method of the present invention catalytically regulate the reversible hydrogen absorption and desorption of the magnesium-nickel-based hydride, the hydride system has the advantages of high reaction activity, fast reaction rate, high hydrogen storage capacity retention rate, and few restrictions on the storage environment. Description of the Drawings

[0026] Figure 1 It is a high-resolution transmission electron microscope image of the Ni-based nano-catalytic particle prepared in Example 1;

[0027] Figure 2The heating thermal decomposition curve of the product of Example 1 tested by a differential scanning calorimeter, with a heating rate of 10 °C / min and an argon gas flow rate of 50 mL / min;

[0028] Figure 3 The programmed heating dehydrogenation curve of the product of Example 1, with a heating rate of 10 °C / min;

[0029] Figure 4 The isothermal hydrogen absorption curve of Example 1 at 200 °C, with a hydrogen absorption pressure of 3 MPa;

[0030] Figure 5 The isothermal hydrogen desorption curve of Example 1 at 200 °C, with a dehydrogenation pressure of 0.005 MPa;

[0031] Figure 6 The isothermal hydrogen absorption and dehydrogenation 20-cycle curve of Example 1 at 215 °C, with a hydrogen absorption pressure of 3 MPa and a dehydrogenation pressure of 0.005 MPa;

[0032] Figure 7 The heating thermal decomposition curve of the product of Comparative Example 1 tested by a differential scanning calorimeter, with a heating rate of 10 °C / min and an argon gas flow rate of 50 mL / min;

[0033] Figure 8 The programmed heating dehydrogenation curve of the product of Comparative Example 1, with a heating rate of 10 °C / min;

[0034] Figure 9 The isothermal hydrogen absorption curve of Comparative Example 1 at 200 °C, with a hydrogen absorption pressure of 3 MPa;

[0035] Figure 10 The isothermal hydrogen desorption curve of Comparative Example 1 at 200 °C, with a dehydrogenation pressure of 0.005 MPa;

[0036] Figure 11 The heating thermal decomposition curve of the product of Example 2 tested by a differential scanning calorimeter, with a heating rate of 10 °C / min and an argon gas flow rate of 50 mL / min;

[0037] Figure 12 The heating thermal decomposition curve of the product of Example 3 tested by a differential scanning calorimeter, with a heating rate of 10 °C / min and an argon gas flow rate of 50 mL / min. Detailed implementation mode

[0038] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation mode and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0039] Example 1

[0040] Magnesium-nickel-based hydride (Mg a Ni b TM c H x ) has an atomic ratio of each component of a:b = 2:1, c = 0, x = 4. The Mg2Ni hydride (Mg2NiH4) and a mixed gas composed of oxygen, water vapor, and nitrogen (volume ratio of 19.99:0.01:80) are sealed in a detachable closed container. The gas pressure is 1.0 MPa, the temperature is 25 °C, and the storage time is 30 days. The formed Ni-based nano-catalytic particle has a particle size of ~5 nm( Figure 1 ), and the peak temperature of the thermal decomposition during heating measured by a differential scanning calorimeter is 248.6 °C( Figure 2 ). The results of temperature-programmed dehydrogenation show that the dehydrogenation capacity is 3.3 wt.%( Figure 3 ), and the isothermal hydrogen absorption( Figure 4 ) and isothermal dehydrogenation( Figure 5 ) curves at 200 °C, as well as the 20-cycle curves of isothermal hydrogen absorption and dehydrogenation at 215 °C( Figure 6 ).

[0041] Comparative Example 1

[0042] Magnesium-nickel-based hydride (Mg a Ni b TM c H x ) has an atomic ratio of each component of a:b = 2:1, c = 0, x = 4. Without any treatment, the Mg2Ni hydride (Mg2NiH4) is used to test its thermal decomposition behavior during heating by a differential scanning calorimeter. The dehydrogenation peak temperature of the sample is 336.9 °C( Figure 7 ), and the dehydrogenation capacity is 3.6 wt.%( Figure 8 ). The isothermal hydrogen absorption( Figure 9 ) and isothermal hydrogen release( Figure 10 ) curves at 200 °C are obtained.

[0043] Example 2

[0044] Magnesium-nickel-based hydride (Mg a Ni b TM c H x ) has an atomic ratio of each component of a:b = 10:1, b:c = 9:1, and TM is metal Co. That is, Mg 90 Ni9CoH x is placed in a glass tube, and a mixed gas composed of oxygen, water vapor, nitrogen, and carbon dioxide (volume ratio of 19:1:79:1) is continuously and slowly introduced into the glass tube. The gas pressure is 0.11 MPa, the temperature is 40 °C, and the gas introduction time is 20 days. The peak temperature of the thermal decomposition during heating measured by a differential scanning calorimeter is 254.3 °C(Figure 11 ), the thermal decomposition temperature is reduced by 104 °C compared to the untreated sample.

[0045] Example 3

[0046] Magnesium-nickel-based hydride (Mg a Ni b TM c H x ), the atomic ratio of each component is a:b = 16:7, b:c = 7:1, TM is metal Cu, that is, Mg2Ni 0.875 Cu 0.125 H x and a mixed gas composed of oxygen, water vapor, argon and carbon dioxide (volume ratio of 19.5:0.5:70:10) are sealed in a detachable airtight container, the gas pressure is 3.0 MPa, the temperature is 25 °C, and the storage time is 50 days. The peak temperature of the thermal decomposition measured by a differential scanning calorimeter is 241.8 °C ( Figure 12 ), the thermal decomposition temperature is reduced by 56 °C compared to the untreated sample.

[0047] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A method for preparing metal-based nano-catalytic particles, characterized in that, The metal-based nano-catalytic particles are prepared by a gas-solid reaction after the mixed gas is contacted with a magnesium-nickel-based alloy and its hydride; The mixed gas includes a reaction gas and a protective gas, and the reaction gas includes at least one of oxygen and water vapor.

2. The preparation method of the metal-based nano-catalytic particles according to claim 1, characterized in that, The chemical formula of the magnesium-nickel-based alloy and its hydride is Mg a Ni b TM c H x ; Among them, the atomic ratio of each component is a:b:c, where 2≤a:b≤10, 1≤b:c≤19 or 2≤a:b≤10, c = 0; TM is a metal element, including cobalt, copper, titanium, iron, chromium, manganese, scandium, yttrium, cerium.

3. The preparation method of the metal-based nano-catalytic particles according to claim 2, wherein When the magnesium-nickel-based alloy and its hydride are an alloy, x = 0; when the magnesium-nickel-based alloy and its hydride are a hydride, x > 0.

4. The preparation method of the metal-based nano-catalytic particles according to claim 1, wherein The particle size of the magnesium-nickel-based alloy and its hydride is 10 - 200 μm.

5. The preparation method of the metal-based nano-catalytic particles according to claim 1, characterized in that, The volume ratio of the reaction gas to the protective gas is 1:9 - 3:

7.

6. The preparation method of the metal-based nano-catalytic particles according to claim 1, characterized in that, The protective gas is at least one of argon, carbon dioxide, and nitrogen.

7. The preparation method of the metal-based nano-catalytic particles according to claim 1, characterized in that The contact method of the mixed gas with the magnesium-nickel-based alloy and its hydride is fully enclosed sealed storage or the mixed gas flows through the surface of the magnesium-nickel-based alloy and its hydride.

8. The preparation method of the metal-based nano-catalytic particles according to claim 1, wherein The pressure of the mixed gas is 0.1 - 5 MPa, the action temperature with the magnesium-nickel-based alloy and its hydride is 10 - 100 °C, and the action time ≤ 100 days.

9. A metal-based nano-catalytic particle, characterized in that, Prepared by the preparation method according to any one of claims 1 - 8, the particle size of the metal-based nano-catalytic particles is 3 - 7 nm.

10. Use of the metal-based nano-catalytic particles according to claim 9, characterized in that, The metal-based nano-catalytic particles are used as a catalyst for a hydrogen storage material.

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