In-situ surface modification method for enhancing the anti-poisoning performance of high-density metal-based hydrogen storage alloys

Abstract

The application discloses an in-situ surface modification method for enhancing the CO2 and CO poisoning resistance of high-density metal-based alloy, which comprises the following steps: 1) carrying out surface modification on the activated dehydrogenated ZrCo-based alloy in a mixed gas of H2 and a modification gas at 350-450 DEG C; the modification gas is at least one of N2 and CO2; and 2) under the condition of dynamic evacuation, cooling the alloy processed in the step 1) to obtain a ZrCo-based alloy with CO2 and CO poisoning resistance. The application adopts the modification strategy of in-situ surface reconstruction, and solves the problem of poor CO2 and CO poisoning resistance of the ZrCo-based alloy. The application has the advantages of simple steps, low cost and high safety, and has important significance for promoting the application and popularization of the ZrCo-based alloy in the field of hydrogen energy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen isotope storage and supply, and particularly relates to an in-situ surface modification method for enhancing the carbon dioxide (CO2) and carbon monoxide (CO) poisoning resistance of high-density ZrCo metal-based hydrogen storage alloy. BACKGROUND

[0002] Deuterium-tritium controlled nuclear fusion technology is one of the main ways to obtain clean energy in the future. During the operation of the nuclear fusion reactor, the safe, stable and efficient supply of deuterium-tritium fuel to the fuel filling system is the key to ensuring the stable operation of the reactor. With the advancement of nuclear fusion projects such as ITER (International Thermonuclear Experimental Reactor), the recycling, storage and supply technology of hydrogen isotopes has become an important research direction. In particular, the management of tritium, a radioactive isotope, presents a particularly significant technical challenge. Tritium not only has radioactivity, but also is scarce in resources, so efficient recycling and safe storage have become an important issue to ensure the sustainable development of nuclear fusion energy. By using high-density metal-based hydrogen storage materials with specific thermodynamic and kinetic properties, safe storage and precise supply of hydrogen isotopes can be achieved. High-density ZrCo metal-based alloy materials have a relatively low hydrogen absorption platform pressure (about 10 -3 Pa) at room temperature, which can efficiently absorb hydrogen isotopes at a relatively low pressure. In addition, the hydrogen absorption and desorption kinetics are fast, and the absorption and desorption reactions can be completed in a short time, meeting the dynamic demand of hydrogen isotopes for fusion reactors. More importantly, ZrCo alloy is non-radioactive, has high safety in use, and has low self-ignition risk, and has good helium fixation performance, which is suitable for use in high-safety environments such as nuclear fusion reactors. Therefore, ZrCo alloy has become an important candidate material for hydrogen isotope storage and supply systems, and has broad application prospects.

[0003] However, ZrCo alloy also encounters some problems in practical application. For example, during the operation of ITER, due to the ablation effect of high temperature generated by deuterium-tritium fusion reaction on the device material, CO2, CO and other impurity gases will inevitably mix in the hydrogen isotope gas. The presence of these oxygen-containing impurity gases will seriously slow down the hydrogen absorption rate of ZrCo-based alloy, and when the content of impurity gas reaches a certain level, the hydrogen storage alloy will even completely lose its activity, thereby affecting the application of ZrCo-based alloy in the field of ITER hydrogen isotope storage. Therefore, it is necessary to develop an effective surface modification method for ZrCo-based alloy to improve the anti-poisoning ability of the alloy and prolong its service life.

[0004] In order to improve the anti-poisoning performance of ZrCo-based alloy, researchers have proposed several solutions. For example, Zhejiang University uses ZrCo alloy to actively perform multiple hydrogen absorption and desorption cycles in H2 containing CO2 impurity gas, thereby in-situ homogeneously constructing Co nanoparticles with high hydrogenation reaction catalytic activity on its surface, thereby improving the anti-CO2 poisoning ability of ZrCo alloy (a method for enhancing the anti-carbon dioxide poisoning performance of ZrCo alloy, patent number: ZL202211727886.0). However, this method requires multiple hydrogen absorption and desorption cycles of ZrCo alloy in mixed gas to achieve the desired anti-poisoning effect, and the process is relatively complex. Moreover, as the hydrogen absorption and desorption cycles proceed, ZrCo alloy will inevitably undergo disproportionation and oxidation reactions with H2 and CO2, respectively, resulting in a continuous decrease in hydrogen storage capacity during the modification process. China Academy of Engineering Physics wraps dense SiO2 on the surface of ZrCo alloy, improving the alloy's resistance to CO, CO2 and air poisoning (a method for enhancing the anti-CO, CO2 and air poisoning and anti-powdering performance of ZrCo alloy, patent number: ZL201410532678.4); Beijing Nonferrous Metals Research Institute modified the surface of ZrCo alloy with Pd or Pd-Ag chemical plating layer. Studies have found that the PdAg / ZrCo alloy after plating the protective layer has increased resistance to CO, CO2 and other impurity gases. However, the above processes also have some shortcomings. They require complex procedures for heterogeneously coating other metal elements on ZrCo, and these coated metal elements themselves cannot effectively store hydrogen and are prone to alloying reactions with Zr or Co elements, resulting in a decrease in the actual mass hydrogen storage capacity of the sample, thereby increasing the difficulty and uncertainty of preparing the sample. At the same time, this non-in-situ grown coating layer is not tightly combined with ZrCo, and is prone to falling off during the recycling process, causing a decrease in anti-poisoning performance. In addition, the cost of Pd / Ag is also relatively high, which is not conducive to large-scale application. In order to further improve the anti-poisoning performance of ZrCo-based alloy, it is necessary to develop a more simple, efficient and cost-controllable in-situ surface modification method. SUMMARY

[0005] In order to solve the problem of poor anti-poisoning performance of ZrCo-based hydrogen isotope storage alloy, an in-situ surface modification method for enhancing the anti-CO2 and CO poisoning performance of high-density ZrCo metal-based hydrogen storage alloy is provided. The hydrogen isotope in the application includes one or more of protium, deuterium and tritium.

[0006] An in-situ surface modification method for enhancing the anti-CO2 and CO poisoning performance of high-density ZrCo metal-based hydrogen storage alloy, comprising the steps of:

[0007] 1) the activated dehydrogenated ZrCo-based alloy is kept at 350-450°C (e.g. 430°C, etc.) in a H2+ modified gas mixture; the modified gas is at least one of N2, CO2;

[0008] 2) the alloy treated in step 1) is cooled under dynamic vacuum to obtain a ZrCo-based alloy with CO2, CO poisoning resistance.

[0009] In step 1), the ZrCo-based alloy can be a ZrCo alloy partially substituted with one or more transition metal elements, which can be selected from Cu, Ni, Hf, Ti, Nb, or unsubstituted.

[0010] In step 1), the ZrCo-based alloy can be a ZrCo alloy, a ZrCo (1-a) Cu a alloy, a ZrCo (1-b) Ni b alloy, a Zr (1-c) Hf c Co alloy, a Zr (1-d) Ti d Co alloy, or a Zr (1-e) Nb e Co alloy, wherein 0

[0011] In step 1), the activated dehydrogenated ZrCo-based alloy can be obtained by:

[0012] casting the ZrCo-based alloy ingot under dynamic vacuum at 400-500°C to remove the impurity gas on the surface of the ZrCo-based alloy ingot; after the vacuum extraction is completed, the temperature is lowered to below 200°C, hydrogen is filled in to activate the ZrCo-based alloy ingot by hydrogen absorption, and then the activated ZrCo-based alloy is dehydrogenated by dynamic vacuum extraction at 500-550°C to obtain the activated dehydrogenated ZrCo-based alloy.

[0013] In step 1), the holding time at 350-450°C can be 3-30 min, such as 5 min, 10 min, 15 min, etc.

[0014] In step 1), the initial back pressure of the introduced H2+ modified gas mixture can be 0.5-4.0 bar, such as 1.2 bar, etc.

[0015] In step 1), the content of the modifying gas in the H2+ modifying gas mixture can be 1-10 mol%, for example, 5 mol%, etc. The balance can be H2.

[0016] The application further provides a ZrCo-based alloy with CO2 and CO poisoning resistance, which is prepared by the in-situ surface modification method. Further, the ZrCo-based alloy with CO2 and CO poisoning resistance shows that a dense and uniform protective layer is formed, and the material of the protective layer can be nitride, etc.

[0017] The application further provides application of the ZrCo-based alloy with CO2 and CO poisoning resistance in storage, supply and recovery of hydrogen isotopes. The hydrogen isotopes can include one or more of protium, deuterium and tritium.

[0018] The application adopts the in-situ surface reconstruction modification strategy to solve the problem of poor CO2 and CO poisoning resistance of the ZrCo-based alloy. The hydrogenation reaction activity of the modified ZrCo-based alloy in the H2 mixed gas containing CO2 and / or CO impurities is significantly enhanced.

[0019] Compared with the prior art, the application has the following beneficial effects:

[0020] 1. The method for in-situ surface modification of the high-density ZrCo-based alloy belongs to in-situ homologous modification, and all operations can be completed in a single hydrogen absorption and desorption system, without the need for an additional heterogeneous coating modification process, thereby avoiding a series of problems such as complexity of sample transfer in different processes and oxidation and pollution.

[0021] 2. The process flow of the application is very simple and has strong operability. Only one modification is needed to achieve the desired effect. Compared with the unmodified ZrCo-based alloy, after the surface of the ZrCo-based alloy is modified by the method, the CO2 and CO poisoning resistance of the alloy during hydrogen absorption in the H2+CO2 / CO mixed gas can be significantly enhanced while maintaining a high capacity, thereby effectively improving the hydrogenation reaction activity of the ZrCo-based alloy, and the application is particularly suitable for hydrogen isotope storage, supply and recovery for ITER.

[0022] 3. The application greatly reduces the modification cost, uses inexpensive N2, CO2 and the like as raw materials, avoids the use of expensive heterogeneous coating raw materials, has simple steps and high safety, is still applicable in the hydrogen isotope scene containing CO2 and CO impurities, and has very important significance for promoting the application and promotion of the ZrCo-based alloy in the field of hydrogen isotope storage. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1A flow chart of the in-situ surface modification method for enhancing the CO2 and CO poisoning resistance of high-density ZrCo metal matrix alloy according to the present application.

[0024] Figure 2 Room temperature hydrogen absorption kinetics plots of ZrCo (ZC) in 10 bar H2 mixed gas containing 2000 ppm (a) CO2 or (b) CO.

[0025] Figure 3 Room temperature hydrogen absorption kinetics plots of Zr 0.8 Hf 0.2 Room temperature hydrogen absorption kinetics plots of ZrCo (ZC) in 10 bar H2 mixed gas containing 2000 ppm (a) CO2 or (b) CO.

[0026] Figure 4 Room temperature hydrogen absorption kinetics plots of Zr 0.8 Nb 0.2 Room temperature hydrogen absorption kinetics plots of ZrCo (ZC) in 10 bar H2 mixed gas containing 2000 ppm (a) CO2 or (b) CO.

[0027] Figure 5 Room temperature hydrogen absorption kinetics plots of Zr 0.8 Ti 0.2 Room temperature hydrogen absorption kinetics plots of ZrCo (ZC) in 10 bar H2 mixed gas containing 2000 ppm (a) CO2 or (b) CO.

[0028] Figure 6 Room temperature hydrogen absorption kinetics plots of ZrCo 0.8 Ni 0.2 Room temperature hydrogen absorption kinetics plots of ZrCo (ZC) in 10 bar H2 mixed gas containing 2000 ppm (a) CO2 or (b) CO.

[0029] Figure 7 Room temperature hydrogen absorption kinetics plots of ZrCo 0.8 Cu 0.2 Room temperature hydrogen absorption kinetics plots of ZrCo (ZC) in 10 bar H2 mixed gas containing 2000 ppm (a) CO2 or (b) CO.

[0030] Figure 8 Room temperature hydrogen absorption kinetics plots of ZrCo and ZrCo sample (ZC-N) modified by surface modification at 430 °C, 1.2 bar 95 mol% H2 + 5 mol% N2 mixed gas for 5-30 min in 10 bar H2 mixed gas containing 2000 ppm CO2.

[0031] Figure 9Room temperature hydrogen uptake kinetics plots for ZrCo and ZrCo surface modified by exposure to 430 °C, 1.2 bar 95 mol% H2 + 5 mol% CO2 mixed gas for 5-30 min (ZC-CO2) in 10 bar H2 containing 2000 ppm (a) CO2 or (b) CO.

[0032] Figure 10 Room temperature hydrogen uptake kinetics plots for ZrCo (ZC) and ZrCo surface modified by exposure to 430 °C, 1.2 bar 95 mol% H2 + 5 mol% N2 mixed gas for 10 min (ZC-N) in 10 bar H2 containing 2000 ppm (a) CO2 or (b) CO.

[0033] Figure 11 Zr 0.8 Hf 0.2 Co (ZHC) and Zr 0.8 Hf 0.2 Co surface modified by exposure to 430 °C, 1.2 bar 95 mol% H2 + 5 mol% N2 mixed gas for 10 min (ZHC-N) in 10 bar H2 containing 2000 ppm (a) CO2 or (b) CO.

[0034] Figure 12 Zr 0.8 Nb 0.2 Co (ZNC) and Zr 0.8 Nb 0.2 Co surface modified by exposure to 430 °C, 1.2 bar 95 mol% H2 + 5 mol% N2 mixed gas for 10 min (ZNC-N) in 10 bar H2 containing 2000 ppm (a) CO2 or (b) CO.

[0035] Figure 13 Zr 0.8 Ti 0.2 Co (ZTC) and Zr 0.8 Ti 0.2 Co surface modified by exposure to 430 °C, 1.2 bar 95 mol% H2 + 5 mol% N2 mixed gas for 10 min (ZTC-N) in 10 bar H2 containing 2000 ppm (a) CO2 or (b) CO.

[0036] Figure 14 ZrCo 0.8 Ni 0.2 (ZCN) and ZrCo 0.8 Ni 0.2Hydrogen absorption kinetics plot of the sample (ZCN-N) after surface modification at 430 °C for 10 min in 1.2 bar 95 mol% H2+5 mol% N2mixture, at room temperature in 10 bar H2mixture containing 2000 ppm (a) CO2or (b) CO.

[0037] Figure 15 ZrCo 0.8 Cu 0.2 (ZCC) and ZrCo 0.8 Cu 0.2 Hydrogen absorption kinetics plot of the sample (ZCC-N) after surface modification at 430 °C for 10 min in 1.2 bar 95 mol% H2+5 mol% N2mixture, at room temperature in 10 bar H2mixture containing 2000 ppm (a) CO2or (b) CO.

[0038] Figure 16 X-ray diffraction (XRD) analysis results of ZrCo, the sample (ZC-N) after surface modification at 430 °C for 10 min in 1.2 bar 95 mol% H2+5 mol% N2mixture, and the sample (ZC-NH) after saturation of hydrogen absorption at room temperature in 10 bar H2mixture containing 2000 ppm CO2.

[0039] Figure 17 Transmission electron microscopy (TEM) image of the sample (ZC-N) after surface modification at 430 °C for 10 min in 1.2 bar 95 mol% H2+5 mol% N2mixture.

[0040] Figure 18 Hydrogen absorption / desorption PCT (pressure-composition-temperature) test results of ZrCo and the sample (ZC-N) after surface modification at 430 °C for 10 min in 1.2 bar 95 mol% H2+5 mol% N2mixture. DETAILED DESCRIPTION

[0041] The present application will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and are not used to limit the scope of the present application.

[0042] The present application is mainly used for surface modification of high-density ZrCo metal-based alloy, so as to enhance its anti-CO2and CO poisoning performance.

[0043] As Figure 1As shown, a process flow for modifying high-density ZrCo metal-based alloy powder according to the present application can be divided into (1) preparing activated dehydrogenated ZrCo-based alloy; (2) introducing 0.5-4.0 bar H2 mixed gas containing 1-10 mol% N2 or CO2 at 350-450°C; (3) surface non-metal modification for 3-30 min; (4) cooling to room temperature under dynamic vacuum, to obtain a modified sample with significantly improved CO2 and CO poisoning resistance.

[0044] Comparative Example 1:

[0045] The elemental Zr and Co with equal atomic ratio were weighed and subjected to magnetic levitation induction melting to prepare a ZrCo alloy ingot with uniform composition. The surface oxide film of the ZrCo alloy obtained by melting was polished off with a grinding wheel, and then the ingot was placed in a reactor, and dynamic vacuum was applied at 500°C for 1 h, and then cooled to 100°C for heat preservation. Subsequently, 20 bar high-purity H2 was added for hydrogen absorption for 10 h, thereby obtaining activated hydrogen-absorbed ZrCoH3 powder.

[0046] The activated hydrogen-absorbed powder was placed in a reactor, and the reactor was heated to 550°C under dynamic vacuum for 0.5 h to completely dehydrogenate, thereby obtaining activated dehydrogenated ZrCo alloy.

[0047] At room temperature, 10 bar H2 mixed gas containing 2000 ppm CO2 or CO was introduced into the activated dehydrogenated ZrCo alloy, and the hydrogen absorption kinetics curve of ZrCo in the mixed gas was measured. As shown, Figure 2 in the H2+CO2 mixed gas, the material can absorb 0.53wt% hydrogen within 20 min; in the H2+CO mixed gas, the material needs 84.3 min to absorb 0.7wt% hydrogen.

[0048] Comparative Example 2:

[0049] The elemental Zr, Hf and Co with an atomic ratio of 0.8:0.2:1 were weighed and subjected to magnetic levitation induction melting to prepare a Zr 0.8 Hf 0.2 Co alloy ingot with uniform composition. The surface oxide film of the Zr 0.8 Hf 0.2 Co alloy obtained by melting was polished off with a grinding wheel, and then the ingot was placed in a reactor, and dynamic vacuum was applied at 500°C for 1 h, and then cooled to 100°C for heat preservation. Subsequently, 20 bar high-purity H2 was added for hydrogen absorption for 10 h, thereby obtaining activated hydrogen-absorbed Zr 0.8 Hf 0.2 CoH3 powder. The activated hydrogen-absorbed powder was placed in a reactor, and the reactor was heated to 550°C under dynamic vacuum for 0.5 h to completely dehydrogenate, thereby obtaining activated dehydrogenated Zr 0.8 Hf 0.2Co alloy.

[0050] At room temperature, to activated dehydrogenated Zr 0.8 Hf 0.2 The Zr content of the Co alloy was measured by introducing a 10 bar H2 mixture containing 2000 ppm CO2 or CO. 0.8 Hf 0.2 Hydrogen absorption kinetics curve of Co in a gas mixture. (See figure) Figure 3 As shown, the time required for the material to absorb 0.7 wt% hydrogen in H2+CO2 and H2+CO mixed gases is 6.6 min and 76.4 min, respectively.

[0051] Comparative Example 3:

[0052] Zr, Nb, and Co in an atomic ratio of 0.8:0.2:1 were weighed and subjected to magnetic levitation induction melting to obtain Zr with uniform composition. 0.8 Nb 0.2 Co alloy ingots. The Zr obtained from smelting... 0.8 Nb 0.2 The oxide film on the surface of the Co alloy was removed by grinding with a grinding wheel. The ingot was then placed in a reactor and dynamically evacuated at 500°C for 1 hour, followed by cooling to 100°C and holding. Subsequently, 20 bar of high-purity H2 was added to absorb hydrogen for 10 hours, thus obtaining activated hydrogen-absorbing Zr. 0.8 Nb 0.2 CoH3 powder. The activated hydrogen-absorbing powder was placed in a reactor, and the reactor was heated to 550℃ and held for 0.5 h under dynamic evacuation conditions to completely dehydrogenate the powder, yielding activated dehydrogenated Zr. 0.8 Nb 0.2 Co2 alloy.

[0053] At room temperature, to activated dehydrogenated Zr 0.8 Nb 0.2 The Zr content of the Co alloy was measured by introducing a 10 bar H2 mixture containing 2000 ppm CO2 or CO. 0.8 Nb 0.2 Hydrogen absorption kinetics curve of Co in a gas mixture. (See figure) Figure 4 As shown, in a mixture of H2+CO2 and H2+CO gas, the material can absorb 0.16wt% and 0.47wt% of hydrogen gas within 20 min and 120 min, respectively.

[0054] Comparative Example 4:

[0055] Zr, Ti, and Co in an atomic ratio of 0.8:0.2:1 were weighed and subjected to magnetic levitation induction melting to obtain Zr with uniform composition. 0.8 Ti 0.2 Co alloy ingots. The Zr obtained from smelting... 0.8 Ti 0.2The surface oxide film of the Co alloy was polished off with a grinding wheel, and then the ingot was placed in a reactor, and dynamic vacuum was extracted at 500°C for 1 h, and then cooled to 100°C for preservation. Subsequently, 20 bar of high-purity H2was added for hydrogen absorption for 10 h, so as to obtain the activated hydrogen absorption state Zr 0.8 Ti 0.2 CoH3powder. The activated hydrogen absorption state powder was placed in a reactor, and the reactor was heated to 550°C for 0.5 h for complete dehydrogenation under dynamic vacuum extraction, so as to obtain the activated dehydrogenation state Zr 0.8 Ti 0.2 Co alloy.

[0056] At room temperature, 10 bar of H2mixed gas containing 2000 ppm CO2or CO was introduced into the activated dehydrogenation state Zr 0.8 Ti 0.2 Co alloy, and the hydrogen absorption kinetics curve of Zr 0.8 Ti 0.2 Co in the mixed gas was measured. As shown in Figure 5 , in the H2+CO2and H2+CO mixed gas, the material can absorb 0.13wt% and 0.33wt% of hydrogen gas within 20 min and 120 min, respectively.

[0057] Comparative Example 5:

[0058] The Zr, Co and Ni elements with an atomic ratio of 1:0.8:0.2 were weighed, and magnetic levitation induction melting was performed, so as to obtain a ZrCo 0.8 Ni 0.2 alloy ingot. The ZrCo 0.8 Ni 0.2 alloy surface oxide film was polished off with a grinding wheel, and then the ingot was placed in a reactor, and dynamic vacuum was extracted at 500°C for 1 h, and then cooled to 100°C for preservation. Subsequently, 20 bar of high-purity H2was added for hydrogen absorption for 10 h, so as to obtain the activated hydrogen absorption state ZrCo 0.8 Ni 0.2 H3powder. The activated hydrogen absorption state powder was placed in a reactor, and the reactor was heated to 550°C for 0.5 h for complete dehydrogenation under dynamic vacuum extraction, so as to obtain the activated dehydrogenation state ZrCo 0.8 Ni 0.2 alloy.

[0059] At room temperature, 10 bar of H2mixed gas containing 2000 ppm CO2or CO was introduced into the activated dehydrogenation state ZrCo 0.8 Ni 0.2 alloy, and the hydrogen absorption kinetics curve of ZrCo 0.8 Ni 0.2 in the mixed gas was measured. As shown in Figure 6As shown, the material can absorb 0.16wt% of hydrogen in H2+CO2 mixed gas within 20 min; and the material can absorb 0.7wt% of hydrogen in H2+CO mixed gas within 101.7 min.

[0060] Comparative Example 6:

[0061] The Zr, Co and Cu elements with an atomic ratio of 1:0.8:0.2 were weighed and subjected to magnetic levitation induction melting to obtain a ZrCo alloy ingot with uniform composition. 0.8 Cu 0.2 The ZrCo alloy ingot was placed in a reactor and subjected to dynamic vacuum at 500°C for 1 h, and then cooled to 100°C for preservation. Subsequently, 20 bar of high-purity H2 was added for hydrogen absorption for 10 h, thereby obtaining an activated hydrogen-absorbed ZrCoH3 powder. 0.8 Cu 0.2 The surface oxide film of the ZrCo alloy was polished off with a grinding wheel, and then the ingot was placed in a reactor and subjected to dynamic vacuum at 500°C for 1 h, and then cooled to 100°C for preservation. Subsequently, 20 bar of high-purity H2 was added for hydrogen absorption for 10 h, thereby obtaining an activated hydrogen-absorbed ZrCoH3 powder. 0.8 Cu 0.2 The activated hydrogen-absorbed ZrCoH3 powder was placed in a reactor and heated to 550°C for 0.5 h under dynamic vacuum to completely dehydrogenate, thereby obtaining an activated dehydrogenated ZrCo alloy. 0.8 Cu 0.2 The ZrCo alloy.

[0062] The activated dehydrogenated ZrCo alloy was introduced into 10 bar of H2 mixed gas containing 2000 ppm of CO2 or CO at room temperature, and the hydrogen absorption kinetics curve of the ZrCo alloy in the mixed gas was measured. 0.8 Cu 0.2 The ZrCo alloy was introduced into 10 bar of H2 mixed gas containing 2000 ppm of CO2 or CO at room temperature, and the hydrogen absorption kinetics curve of the ZrCo alloy in the mixed gas was measured. 0.8 Cu 0.2 The hydrogen absorption kinetics curve in the mixed gas. As shown, the material can absorb 0.04wt% of hydrogen in H2+CO2 mixed gas within 20 min, and can absorb 0.24wt% of hydrogen in H2+CO mixed gas within 120 min. Figure 7

[0063] Example 1:

[0064] The Zr and Co elements with equal atomic ratio were weighed and subjected to magnetic levitation induction melting to obtain a ZrCo alloy ingot with uniform composition. The surface oxide film of the ZrCo alloy was polished off with a grinding wheel, and then the ingot was placed in a reactor and subjected to dynamic vacuum at 500°C for 1 h, and then cooled to 100°C for preservation. Subsequently, 20 bar of high-purity H2 was added for hydrogen absorption for 10 h, thereby obtaining an activated hydrogen-absorbed ZrCoH3 powder.

[0065] The activated hydrogen-absorbed ZrCoH3 powder was placed in a reactor and heated to 550°C for 0.5 h under dynamic vacuum to completely dehydrogenate, thereby obtaining an activated dehydrogenated ZrCo alloy.

[0066] ​The activated dehydrogenated ZrCo alloy was furnace-cooled to 430°C, then 1.2 bar of 95 mol% H2+5 mol% N2or 95 mol% H2+5 mol% CO2mixed gas was introduced, and the sample was kept for 5 / 10 / 15 / 30 min. Next, the sample was cooled to room temperature under dynamic vacuum, and a surface-modified ZrCo alloy sample was obtained.

[0067] The surface-modified ZrCo alloy sample was introduced with 10 bar of H2mixed gas containing 2000 ppm CO2at room temperature, and the hydrogen absorption kinetics curve of ZrCo in the mixed gas was measured. As shown in FIG. 2, as the modification time in the H2+N2or CO2mixed gas was prolonged from 5 min to 10 min, 15 min, and 30 min, the ability of the sample to resist CO2poisoning gradually increased, and the hydrogen absorption rate in the H2+CO2mixed gas gradually increased. As a preferred embodiment, the sample (ZC-N) surface-modified in the H2+N2mixed gas for 10 min has both a high capacity and excellent resistance to poisoning, and can absorb 1.9 wt% of H2in 40 s. As shown in FIG. 3, the ZC-N sample has significantly improved resistance to CO2and CO poisoning. In the H2+CO2and H2+CO mixed gas, the time required for the material to absorb 0.7 wt% of hydrogen is 0.1 min and 7.1 min, respectively. Figure 8 、 Figure 9 Figure 10

[0068] Example 2:

[0069] The Zr, Hf, and Co elements with an atomic ratio of 0.8:0.2:1 were weighed and subjected to magnetic levitation induction melting to obtain a Zr 0.8 Hf 0.2 Co alloy ingot with uniform composition. The surface oxide film of the Zr 0.8 Hf 0.2 Co alloy ingot was polished off with a grinding wheel, and then the ingot was placed in a reactor and dynamically vacuumed at 500°C for 1 h, and then cooled to 100°C for keeping. Then, 20 bar of high-purity H2was added to absorb hydrogen for 10 h, thereby obtaining an activated hydrogen-absorbed Zr 0.8 Hf 0.2 CoH3powder. The activated hydrogen-absorbed powder was placed in a reactor, and the reactor was heated to 550°C for 0.5 h under dynamic vacuum to completely dehydrogenate, thereby obtaining an activated dehydrogenated Zr 0.8 Hf 0.2 Co alloy.

[0070] The activated dehydrogenated Zr 0.8 Hf 0.2 ​​The Co alloy was cooled to 430°C in the furnace, followed by the introduction of a 1.2 bar mixture of 95 mol% H₂ and 5 mol% N₂, and held at that temperature for 10 min. Next, the sample was cooled to room temperature under dynamic evacuation conditions to obtain the surface-modified Zr. 0.8 Hf 0.2 Co alloy sample (ZHC-N).

[0071] At room temperature, a 10 bar H2 mixture containing 2000 ppm CO2 or CO was introduced into ZHC-N, and its hydrogen absorption kinetics in the mixture were measured. Figure 11 As shown, the ZHC-N sample exhibits significantly enhanced resistance to CO2 and CO poisoning. In H2+CO2 and H2+CO mixed gases, the time required for the material to absorb 0.7wt% hydrogen is 6.6 min and 76.4 min, respectively.

[0072] Example 3:

[0073] Zr, Nb, and Co in an atomic ratio of 0.8:0.2:1 were weighed and subjected to magnetic levitation induction melting to obtain Zr with uniform composition. 0.8 Nb 0.2 Co alloy ingots. The Zr obtained from smelting... 0.8 Nb 0.2 The oxide film on the surface of the Co alloy was removed by grinding with a grinding wheel. The ingot was then placed in a reactor and dynamically evacuated at 500°C for 1 hour, followed by cooling to 100°C and holding. Subsequently, 20 bar of high-purity H2 was added to absorb hydrogen for 10 hours, thus obtaining activated hydrogen-absorbing Zr. 0.8 Nb 0.2 CoH3 powder. The activated hydrogen-absorbing powder was placed in a reactor, and the reactor was heated to 550℃ and held for 0.5 h under dynamic evacuation conditions to completely dehydrogenate the powder, yielding activated dehydrogenated Zr. 0.8 Nb 0.2 Co alloy.

[0074] The activated dehydrogenated Zr 0.8 Nb 0.2 The Co alloy was cooled to 430°C in the furnace, followed by the introduction of a 1.2 bar mixture of 95 mol% H₂ and 5 mol% N₂, and held at that temperature for 10 min. Next, the sample was cooled to room temperature under dynamic evacuation conditions to obtain the surface-modified Zr. 0.8 Nb 0.2 Co alloy sample (ZNC-N).

[0075] At room temperature, a mixture of H2 gas containing 2000 ppm CO2 or CO at 10 bar was introduced into ZNC-N, and its hydrogen absorption kinetics in the mixture were measured. Figure 12As shown, the ZNC-N sample exhibits significantly enhanced resistance to CO2 and CO poisoning. In H2+CO2 and H2+CO mixed gases, the time required for the material to absorb 0.7wt% hydrogen is 2.7 min and 47.9 min, respectively.

[0076] Example 4:

[0077] Zr, Ti, and Co in an atomic ratio of 0.8:0.2:1 were weighed and subjected to magnetic levitation induction melting to obtain Zr with uniform composition. 0.8 Ti 0.2 Co alloy ingots. The Zr obtained from smelting... 0.8 Ti 0.2 The oxide film on the surface of the Co alloy was removed by grinding with a grinding wheel. The ingot was then placed in a reactor and dynamically evacuated at 500°C for 1 hour, followed by cooling to 100°C and holding. Subsequently, 20 bar of high-purity H2 was added to absorb hydrogen for 10 hours, thus obtaining activated hydrogen-absorbing Zr. 0.8 Ti 0.2 CoH3 powder. The activated hydrogen-absorbing powder was placed in a reactor, and the reactor was heated to 550℃ and held for 0.5 h under dynamic evacuation conditions to completely dehydrogenate the powder, yielding activated dehydrogenated Zr. 0.8 Ti 0.2 Co alloy.

[0078] The activated dehydrogenated Zr 0.8 Ti 0.2 The Co alloy was cooled to 430°C in the furnace, followed by the introduction of a 1.2 bar mixture of 95 mol% H₂ and 5 mol% N₂, and held at that temperature for 10 min. Next, the sample was cooled to room temperature under dynamic evacuation conditions to obtain the surface-modified Zr. 0.8 Ti 0.2 Co alloy sample (ZTC-N).

[0079] At room temperature, a 10 bar H2 mixture containing 2000 ppm CO2 or CO was introduced into the ZTC-N, and its hydrogen absorption kinetics in the mixture were measured. Figure 13 As shown, the ZTC-N sample exhibits significantly enhanced resistance to CO2 and CO poisoning. In an H2+CO2 mixture, the material requires 5.6 min to absorb 0.70 wt% hydrogen; in an H2+CO mixture, the material can absorb 0.56 wt% hydrogen within 120 min.

[0080] Example 5:

[0081] Zr, Co, and Ni in an atomic ratio of 1:0.8:0.2 were weighed and subjected to magnetic levitation induction melting to obtain ZrCo with uniform composition. 0.8 Ni 0.2 Alloy ingots. The ZrCo obtained from smelting...0.8 Ni 0.2 The surface oxide film of the alloy was polished off with a grinding wheel, and then the ingot was placed in a reactor, and dynamic vacuum was extracted at 500°C for 1 h, and then cooled to 100°C for preservation. Subsequently, 20 bar of high-purity H2was added to absorb hydrogen for 10 h, so as to obtain the activated hydrogen-absorbed-state ZrCo 0.8 Ni 0.2 H3powder. The activated hydrogen-absorbed-state powder was placed in a reactor, and the reactor was heated to 550°C for 0.5 h under dynamic vacuum extraction conditions to completely dehydrogenate, so as to obtain the activated dehydrogenated-state ZrCo 0.8 Ni 0.2 alloy.

[0082] The activated dehydrogenated-state ZrCo 0.8 Ni 0.2 alloy was cooled to 430°C in the furnace, and then 1.2 bar of 95 mol% H2+ 5 mol% N2mixed gas was introduced, and preserved for 10 min. Next, the sample was cooled to room temperature under dynamic vacuum extraction conditions, so as to obtain the ZrCo 0.8 Ni 0.2 alloy sample (ZCN-N).

[0083] At room temperature, 10 bar of H2mixed gas containing 2000 ppm CO2or CO was introduced into the ZCN-N, and the hydrogen absorption kinetics curve thereof in the mixed gas was measured. As shown in Figure 14 , the CO2and CO poisoning resistance of the ZCN-N sample was significantly improved, and the time required for the material to absorb 0.7 wt% of hydrogen in the H2+CO2and H2+CO mixed gas was 8.4 min and 55.0 min, respectively.

[0084] Example 6:

[0085] Zr, Co and Cu elements with an atomic ratio of 1:0.8:0.2 were weighed, and magnetic levitation induction melting was performed to prepare a ZrCo 0.8 Cu 0.2 alloy ingot. The ZrCo 0.8 Cu 0.2 alloy ingot. The ZrCo 0.8 Cu 0.2 H3powder. The activated hydrogen-absorbed-state powder was placed in a reactor, and the reactor was heated to 550°C for 0.5 h under dynamic vacuum extraction conditions to completely dehydrogenate, so as to obtain the activated dehydrogenated-state ZrCo 0.8 Cu 0.2 alloy.

[0086] The activated dehydrogenated ZrCo 0.8 Cu 0.2 The alloy was furnace cooled to 430℃, then 1.2bar 95mol% H2+5mol% N2mixed gas was introduced, and kept for 10min. Next, the sample was cooled to room temperature under dynamic evacuation, and a surface modification modified ZrCo 0.8 Cu 0.2 The alloy sample (ZCC-N).

[0087] At room temperature, 10bar H2mixed gas containing 2000ppm CO2or CO was introduced into ZCC-N, and the hydrogen absorption kinetics curve in the mixed gas was measured. As shown in Figure 15 The ZCC-N sample significantly improved the resistance to CO2and CO poisoning, and the material could absorb 0.27wt% and 0.36wt% of hydrogen within 20min and 120min, respectively.

[0088] Example 7:

[0089] The unmodified activated dehydrogenated ZrCo alloy, the sample of ZrCo in Example 1 nitrided at 430℃ for 10min in 1.2bar 95mol% H2+5mol% N2mixed gas (ZC-N), and the sample of ZC-N saturated with hydrogen absorption in 10bar H2mixed gas containing 2000ppm CO2 / CO (ZC-NH) were respectively subjected to XRD test, as shown in Figure 16 The main phase of the sample modified by nitridation was basically the same as that of the unmodified sample, both being BCC-ZrCo phase, indicating that the nitridation modification mainly modified the surface area of ZrCo particles and did not affect the main phase structure of the material. The sample modified by surface modification was completely converted into ZrCoH3phase after room temperature hydrogen absorption saturation in 10bar H2mixed gas containing 2000ppm CO2, indicating that it could quickly absorb hydrogen to saturation in H2containing non-hydrogen impurity gas, further proving the effectiveness of the application in enhancing the resistance to poisoning of ZrCo alloy.

[0090] Example 8:

[0091] The sample of ZrCo in Example 1 nitrided at 430℃ for 10min in 1.2bar 95mol% H2+5mol% N2mixed gas (ZC-N) was subjected to transmission electron microscopy characterization, as shown in Figure 17 After nitridation, a uniform and dense nitride protective layer was generated on the surface of ZrCo. The protective layer can hinder the impurity gas from contacting the surface of ZrCo, while selectively permeating H2, thereby improving the resistance to poisoning of the material.

[0092] Example 9:

[0093] Hydrogen absorption / desorption PCT tests were performed on the unmodified ZrCo alloy, the sample of ZrCo in Example 1 nitrided at 430°C, 1.2 bar, 95 mol% H2+5 mol% N2mixture for 10 min (ZC-N), and the sample of ZrCo in Example 1 modified by surface nitridation at 430°C, 1.2 bar, 95 mol% H2+5 mol% N2mixture for 10 min (ZC-N-M), respectively, as shown in Figure 2. It can be seen that the PCT curve shape and the hydrogen absorption / desorption plateau pressure of the modified sample are almost the same as those of the unmodified, indicating that the surface nitridation modification method described in the present application does not affect the thermodynamic properties of the ZrCo-based alloy in hydrogen absorption / desorption. Figure 18

[0094] It should be understood, moreover, that it is not necessarily limited to particular embodiments described, as such may vary. It is also to be understood that the terminology employed above is for purpose of describing particular embodiments, and is not intentionally limiting. The use of any and all examples, or exemplary language (e.g., "may", "should", "can", "could", "might", "typically", "often", "typically", "usually", "a number of", "several", "various", "many", "numerous", "some") provided herein is intended merely to better illuminate the present disclosure and is not intended to limit the scope of the present application unless otherwise indicated.​

Claims

1. An in-situ surface modification method for enhancing the CO2, CO poisoning resistance of high-density ZrCo metal-based hydrogen storage alloys, characterized in that, The method comprises the steps of: 1) The activated dehydrogenated ZrCo-based alloy is surface-modified by holding it at 350 - 450 °C for 3 - 30 min in a mixed gas of H2 + modifying gas; the ZrCo-based alloy is ZrCo alloy, ZrCo (1-a) Cu a alloy, ZrCo (1-b) Ni b alloy, Zr (1-c) Hf c Co alloy, Zr (1-d) Ti d Co alloy or Zr (1-e) Nb e Co alloy, where 0 < a < 0.4, 0 < b < 0.4, 0 < c < 0.4, 0 < d < 0.4, 0 < e < 0.4; the modifying gas is at least one of N2 and CO2; the content of the modifying gas in the H2 + modifying gas mixture is 1 mol% - 10 mol%; the initial back pressure of the introduced H2 + modifying gas mixture is 0.5 - 4.0 bar; 2) cooling the alloy treated in step 1) under dynamic vacuum to obtain a ZrCo-based alloy with anti-CO2 and CO poisoning performance.

2. The in situ surface modification method of claim 1, wherein, In step 1), the activated dehydrogenated ZrCo-based alloy is obtained by the following method: The ZrCo-based alloy ingot is dynamically vacuumed at 400-500 DEG C to remove impurity gases on the surface of the ZrCo-based alloy ingot; after the vacuuming is completed, the temperature is lowered to below 200 DEG C, hydrogen is filled in, the surface-degassed ZrCo-based alloy ingot is activated by hydrogen absorption, then the temperature is raised to 500-550 DEG C, the activated ZrCo-based alloy is dynamically vacuumed and dehydrogenated to obtain the activated dehydrogenated ZrCo-based alloy.

3. A ZrCo-based alloy having resistance to CO2, CO poisoning, characterized in that, Prepared by the in-situ surface modification method of claim 1 or 2.

4. Application of the ZrCo-based alloy with anti-CO2 and CO poisoning performance of claim 3 in storage, supply and recovery of hydrogen isotopes.

5. Use according to claim 4, characterized in that, The hydrogen isotopes include one or more of protium, deuterium and tritium.

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