Synthesis method of group IIIB rare earth metal hydride

Abstract

The invention relates to the field of hydride preparation, in particular to a synthesis method of a group IIIB rare earth metal hydride, which comprises the following steps: adding reactants into a reaction kettle, adding a solvent into the reaction kettle, adding NaF into the reaction kettle, enabling the reactants to be at least one of group IIIB rare earth metal simple substance or alloy, enabling the solvent to be an acid solution or an alcohol solution, and enabling the NaF to be added into the reaction kettle; feeding the reaction kettle into a drying oven for heating; and washing and drying the heated sample to obtain a finished product. According to the present invention, the metal hydride can be synthesized by using the hydrothermal reaction (hydrogen embrittlement effect) under the mild condition without directly using hydrogen, such that the vacancy of the hydride synthesis technology is filled, and the condition is provided for the research in the metal hydride field.

Description

Technical Field

[0001] The present invention relates to the field of hydride preparation, and particularly to a method for synthesizing rare earth metal hydrides of Group IIIB. Background Art

[0002] The hydrogen embrittlement effect is an important failure mechanism that has long been concerned in the field of materials science. It refers to the phenomenon that hydrogen atoms invade the metal lattice driven by stress or chemical potential, resulting in a decrease in the toughness of the material and brittle fracture. Among them, hydride embrittlement, as a typical form of hydrogen embrittlement, is manifested as the enrichment and diffusion of hydrogen atoms at bulk defects (grain boundaries or dislocations) to form brittle hydride phases (such as titanium hydride, zirconium hydride), ultimately leading to catastrophic failures in key fields such as nuclear power and aerospace. Traditional research has focused on hydrogen embrittlement inhibition strategies, including material composition optimization (such as adding hydrogen trap elements), surface protective coatings (such as ceramic coatings), and environmental hydrogen concentration control. However, existing strategies are mostly based on the idea of "passive defense" and lack an in-depth understanding of the dynamic evolution mechanism of hydrogen embrittlement. In particular, there are still controversies about the microscopic kinetic processes of hydrogen atom diffusion-bonding-phase transformation. Regarding hydrogen embrittlement simply as the "prime culprit of failure" while ignoring the potential for controllable synthesis of hydrides hidden behind it, this cognitive limitation urgently needs to be broken through.

[0003] Traditional hydride synthesis mainly relies on complex processes such as hydrogenation (high temperature, high pressure), chemical vapor deposition (CVD), and mechanical alloying, facing challenges such as high energy consumption, complex preparation processes, limited product purity (derived oxidation phase by-products), and difficult structure regulation (such as grain coarsening, uncontrollable defects). In contrast, the characteristic that hydrogen atoms spontaneously invade the metal lattice and form ordered hydrides in the phenomenon of hydride embrittlement precisely reveals the potential of the metal itself as a "dynamic reactor": the lattice distortion during the hydrogen embrittlement process may provide a directional diffusion channel for hydrogen atoms, and stress-induced electron rearrangement may stabilize the hydride phase. If the "destructiveness" of hydrogen embrittlement is reversely transformed into "constructiveness", it is expected to achieve controllable synthesis of hydrides under mild conditions and break through the temperature / pressure limitations of traditional methods. Summary of the Invention

[0004] The present invention proposes a new strategy of "hydrogen embrittlement synthesis", which drives the controllable synthesis of hydrides through the hydrogen embrittlement effect. Using multi-scale metals (metal foils, powders, etc.) and (hydrochloric acid / sulfuric acid / oleic acid / ethanol, etc.) as precursors, by regulating the concentration of the proton source (hydrochloric acid / sulfuric acid / oleic acid / ethanol, etc.), the creation of high-purity hydrides is successfully achieved under mild conditions (70 - 280 °C). The purpose of the present invention is to provide a process for synthesizing metal hydrides under mild conditions using a proton source as the hydrogen source and utilizing the hydrogen embrittlement effect. This process has the advantages of low equipment investment (no need for large equipment), cleanliness (no use of fossil energy, no CO2 emissions), and applicability to regional production, etc.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for synthesizing rare earth metal hydrides of Group IIIB, comprising the following steps:

[0007] Add the reactants into a reaction kettle, add a solvent and NaF into the reaction kettle. The reactants are at least one of rare earth metal simple substances or alloys of Group IIIB, and the solvent is an acid solution or an alcohol solution. Then send the reaction kettle into an oven for heating; wash and dry the heated sample to obtain the finished product. Hydrogen is not required during the production of hydrides, and the source of hydrogen is the solvent. If the reactant is Sc and the solution is oleic acid, the reaction is: Sc + 2C 17 H 33 COOH = (C 17 H 33 COO)2Sc + ScH2. Similar reactions will occur for other reactants. The Group IV / VB transition metals are at least one of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No and Lr.

[0008] As a further scheme of the present invention: The reactants are metal blocks, metal foils or metal powders, and can also be nano metal simple substances or nano metal compounds.

[0009] As a further scheme of the present invention: The acid solution is an inorganic acid solution or an organic acid solution, and the concentration of the acid solution is 0.1 - 2 mol / L.

[0010] As a further scheme of the present invention: The inorganic acid is at least one of hydrochloric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, hydrofluoric acid, hydrosulfuric acid, carbonic acid, phosphoric acid, boric acid, silicic acid, arsenic acid, antimonic acid, titanic acid, tungstic acid, stannic acid and zincic acid.

[0011] As a further scheme of the present invention: The organic acid is at least one of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, capric acid, lauric acid, palmitic acid, stearic acid, palmitoleic acid, linoleic acid, linolenic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, citric acid, malic acid, tartaric acid, benzoic acid, o-hydroxybenzoic acid, terephthalic acid and caffeic acid.

[0012] As a further scheme of the present invention: The alcohol in the alcohol solution is at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, tert-butanol, allyl alcohol, propargyl alcohol, cyclohexanol, benzyl alcohol, ethylene glycol, glycerol and pentaerythritol.

[0013] As a further solution of the present invention: the temperature in the oven is 70 - 280 °C, preferably 150 - 250 °C.

[0014] As a further solution of the present invention: the washing is carried out using n - hexane.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] The present invention can synthesize metal hydrides by using hydrothermal reaction (hydrogen embrittlement effect) under relatively mild conditions without directly using hydrogen, filling the gap in the synthesis technology of such hydrides and providing conditions for the research in the field of metal hydrides. Description of the Drawings

[0017] Figure 1 It is the XRD pattern of the formation process of scandium hydride.

[0018] Figure 2 It is the SEM image of scandium hydride.

[0019] Figure 3 It is the XRD pattern of the formation process of yttrium hydride.

[0020] Figure 4 It is the SEM image of yttrium hydride.

[0021] Figure 5 It is the XRD pattern of the formation process of lanthanum hydride.

[0022] Figure 6 It is the SEM image of lanthanum hydride.

[0023] Figure 7 It is the XRD pattern of the formation process of samarium hydride.

[0024] Figure 8 It is the SEM image of samarium hydride.

[0025] Figure 9 It is the XRD pattern of the formation process of lutetium hydride.

[0026] Figure 10 It is the SEM image of lutetium hydride. Detailed Embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0028] Example 1 Preparation of Scandium Hydride

[0029] Refer to Figure 1 - Figure 2 , in an inert gas (argon) glove box, scandium foil and oleic acid were added to the inner lining of a 5 ml PPL reactor, and then encapsulated in a reactor of the same volume and transferred to an oven for heating. After natural cooling, it was washed with n-hexane, and the obtained product after drying was ScH₂. Further, the present invention can control the thickness of the metal foil, reaction time, and reaction temperature to regulate the metal hydride product. Each piece of yttrium metal foil (0.5 mm × 0.5 mm × 0.025 mm), the reaction temperature was 270 °C, and the reaction time was 60 hours, and ScH₂ with good purity was obtained. The relationship between the specific conditions and the product is shown in Table 1.

[0030] Table 1 Relationship between temperature and product purity

[0031] Condition 280℃20h 280℃40h 280℃60h Product <![CDATA[60% ScH 0.33 + 40% ScH2]]> <![CDATA[40% ScH 0.33 + 60% ScH2]]> <![CDATA[ScH2]]>

[0032] Figure 1 are the XRD patterns corresponding to different reaction conditions. From Figure 1 it can be seen that at the beginning stage of the reaction (280 °C, 20 h), the XRD diffraction peaks were mainly ScH 0.33 , and the peak intensity of ScH₂ was very weak, indicating that the product was mainly metal ScH 0.33 at this time, and the yield of ScH₂ was very low; when the reaction proceeded to (280 °C, 40 h - 60 h), it was found from the XRD pattern that the diffraction peaks of ScH₂ continuously increased, and ScH₂ was completely formed at (280 °C, 60 h). The purity of the product was obtained by XRD quantitative analysis.

[0033] Example 2 Preparation of yttrium hydride

[0034] Refer to Figure 3 - Figure 4 , in an inert gas (argon) glove box, yttrium foil and oleic acid were added to the inner lining of a 5 ml PPL reactor, and then encapsulated in a reactor of the same volume and transferred to an oven for heating for 10 hours. After natural cooling, it was washed with n-hexane, and the obtained product after drying was YH₂; each piece of yttrium metal foil (0.5 mm × 0.5 mm × 0.025 mm), the reaction temperature was 270 °C, and the reaction time was 10 hours, and YH₂ with good purity was obtained. The relationship between the specific conditions and the product is shown in Table 2.

[0035] Table 2 Relationship between temperature and product purity

[0036] Condition 280℃6h 280℃8h 280℃10h Product <![CDATA[80% Y + 20% YH2]]> <![CDATA[60% Y + 40% YH2]]> <![CDATA[90% Y + 10% YH2]]> Condition 280℃12h 280℃14h 280℃16h Product <![CDATA[YH2]]> <![CDATA[40% YH3 + 60% YH2]]> <![CDATA[60% YH3 + 40% YH2]]>

[0037] Figure 3 are the XRD patterns corresponding to different reaction conditions. From Figure 3It can be seen that at the beginning stage of the reaction (280 °C for 6 h), the XRD diffraction peaks are mainly Y, and the peak intensity of YH2 is very weak, indicating that the product is mainly metallic Y at this time and the yield of YH2 is very low; when the reaction proceeds to (280 °C for 8 h - 12 h), it can be found from the XRD pattern that the diffraction peaks of YH2 continuously increase, and YH2 is completely formed at (280 °C for 12 h). As the reaction continues, it can be found from the XRD pattern that in the stage of (280 °C for 12 h - 16 h), the intensity of YH3 continuously increases, indicating that the yield of YH3 is continuously increasing at this time. The purity of the product is obtained by XRD quantitative analysis.

[0038] Preparation of Lanthanum Hydride in Example 3

[0039] Refer to Figure 5 - Figure 6 , add lanthanum foil and oleic acid into the inner lining of a 5 ml PPL reactor in an inert gas (argon) glove box, then encapsulate it in a reactor of the same volume and transfer it to an oven for heating for 10 hours. After natural cooling, wash it with n-hexane, and the obtained product after drying is LaH2; for each piece of yttrium metal foil (0.5 mm × 0.5 mm × 0.025 mm), the reaction temperature is 140 °C and the reaction time is 10 hours, and LaH2 with good purity is obtained. The relationship between the specific conditions and the product is shown in Table 3.

[0040] Table 3 Relationship between Temperature and Product Purity

[0041] Condition 140℃12h 140℃14h Product <![CDATA[LaH2]]> <![CDATA[LaH 2.3 >

[0042] Figure 5 are the XRD patterns corresponding to different reaction conditions. It can be seen from Figure 5 that when the reaction conditions are (140 °C for 20 h), the XRD diffraction peaks are mainly LaH2 and there are no other diffraction peaks, indicating that the product is metallic LaH2 at this time and the purity is relatively high; when the reaction proceeds to (140 °C for 15 h), it can be found from the XRD pattern that the XRD diffraction peaks are mainly LaH 2.3 and there are no other diffraction peaks, indicating that the product is metallic LaH 2.3 and the purity is relatively high. The purity of the product is obtained by XRD quantitative analysis.

[0043] Preparation of Samarium Hydride in Example 4

[0044] Refer to Figure 7 - Figure 8, in an inert gas (argon) glove box, samarium foil and oleic acid were added to the inner lining of a 5 ml PPL reactor, and then it was encapsulated in a reactor of the same volume and transferred to an oven for heating for 20 hours. After natural cooling, it was washed with n-hexane, and the obtained product after drying was SmH₂; each piece of yttrium metal foil (0.5 mm × 0.5 mm × 0.025 mm), the reaction temperature was 270 °C, and the reaction time was 20 hours, and SmH₂ with good purity was obtained. The relationship between the specific conditions and the product is shown in Table 4.

[0045] Table 4 Relationship between temperature and product purity

[0046] Condition 270℃20h Product <![CDATA[SmH2]]>

[0047] Figure 7 are the XRD patterns corresponding to different reaction conditions. From Figure 7 it can be seen that at the beginning of the reaction (180 °C for 7 h), the XRD diffraction peaks were mainly NbH and there were no other diffraction peaks, indicating that the product was completely formed as NbH; as the reaction proceeded (180 °C for 8 - 9 h), it was found from the XRD pattern that the diffraction peaks of NbH₂ gradually began to increase and reached the strongest at (180 °C for 10 h), and the peaks of NbH completely disappeared, indicating that NbH₂ was formed at this time. The purity of the product was obtained by XRD quantitative analysis.

[0048] Example 5 Preparation of lutetium hydride

[0049] Refer to Figure 9 - Figure 10 , in an inert gas (argon) glove box, lutetium foil and oleic acid were added to the inner lining of a 5 ml PPL reactor, and then it was encapsulated in a reactor of the same volume and transferred to an oven for heating for 60 hours. After natural cooling, it was washed with n-hexane, and the obtained product after drying was LuH₂; each piece of yttrium metal foil (0.5 mm × 0.5 mm × 0.025 mm), the reaction temperature was 270 °C, and the reaction time was 60 hours, and LaH₂ with good purity was obtained. The relationship between the specific conditions and the product is shown in Table 5.

[0050] Table 5 Relationship between temperature and product purity

[0051] Condition 270℃20h 270℃40h 270℃60h Product <![CDATA[80% Lu + 20% LuH2]]> <![CDATA[40% Lu + 60% LuH2]]> <![CDATA[LuH2]]>

[0052] Figure 9 are the XRD patterns corresponding to different reaction conditions. From Figure 9It can be seen that at the beginning stage of the reaction (270 °C for 20 h), the XRD diffraction peaks are mainly Lu, and the peak intensity of LuH2 is very weak, indicating that the product is mainly metallic Lu at this time and the yield of LuH2 is very low; when the reaction proceeds to (280 °C for 40 h - 80 h), it can be found from the XRD pattern that the diffraction peaks of LuH2 continuously increase and LuH2 is completely formed at (280 °C for 80 h). The purity of the product is obtained by XRD quantitative analysis.

[0053] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for synthesizing rare earth metal hydrides of Group IIIB, characterized in that, It includes the following steps: Add the reactants into a reaction kettle, add a solvent and NaF into the reaction kettle. The reactants are at least one of group IIIB rare earth metal simple substances or alloys, the solvent is an acid solution or an alcohol solution, and then send the reaction kettle into an oven for heating; wash and dry the heated sample to obtain the finished product.

2. The synthesis method of the rare earth metal hydride of Group IIIB according to claim 1, characterized in that, The reactants are metal blocks, metal foils or metal powders.

3. The synthesis method of the rare earth metal hydride of Group IIIB according to claim 1, characterized in that, The acid solution is an inorganic acid solution or an organic acid solution.

4. The synthesis method of group IIIB rare earth metal hydride according to claim 3, characterized in that, The inorganic acid is at least one of hydrochloric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, hydrofluoric acid, hydrosulfuric acid, carbonic acid, phosphoric acid, boric acid, silicic acid, arsenic acid, antimonous acid, titanic acid, tungstic acid, stannic acid and zincic acid.

5. The synthesis method of the rare earth metal hydride of Group IIIB according to claim 3 or 4, characterized in that, The organic acid is at least one of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, capric acid, lauric acid, palmitic acid, stearic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, citric acid, malic acid, tartaric acid, benzoic acid, o-hydroxybenzoic acid, terephthalic acid and caffeic acid.

6. The synthesis method of the rare earth metal hydride of Group IIIB according to claim 5, characterized in that, The alcohol in the alcohol solution is at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, tert-butanol, allyl alcohol, propargyl alcohol, cyclohexanol, benzyl alcohol, ethylene glycol, glycerol and pentaerythritol.

7. The synthesis method of the Group IIIB rare earth metal hydride according to claim 1 or 2, characterized in that, The temperature in the oven is 70 - 280 °C.

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