CN-120717408-B - Nb4N5Ni-based active substance loaded magnesium-based hydrogen storage material and preparation method and application thereof

Abstract

The invention relates to a magnesium-based hydrogen storage material loaded with Ni-based active substances by Nb 4 N 5 , and a preparation method and application thereof, belonging to the field of hydrogen storage materials. Based on MgH 2 as a material, the invention is prepared by adding 3-15 wt.% of Ni (OH) 2 @Nb 4 N 5 or NiO@Nb 4 N 5 composite catalyst by the steps of dissolution, hydrothermal reaction, nitridation, stirring reaction, centrifugal washing, drying, mechanical ball milling and the like. Wherein, nb 4 N 5 is used as a carrier to uniformly load Ni (OH) 2 or NiO, so as to form the composite catalyst. The magnesium-based hydrogen storage material has excellent hydrogen absorption and desorption performance, improves the hydrogen storage capacity and the dynamic performance, provides a new material selection for the solid hydrogen storage field, and has wide application prospect.

Inventors

• CHEN YUAN
• Yong Meiqi
• Wan Haiyi
• QIU JUNQI
• HU YANG
• GUO ZIYI
• WANG JINGFENG
• PAN FUSHENG

Assignees

• 重庆新型储能材料与装备研究院
• 重庆大学

Dates

Publication Date

20260508

Application Date

20250625

Claims (5)

1. The magnesium-based hydrogen storage material loaded with Ni-based active substances by Nb 4 N 5 is characterized by comprising MgH 2 and any one compound of Ni (OH) 2 @Nb 4 N 5 or NiO@Nb 4 N 5 ; The magnesium-based hydrogen storage material comprises MgH 2 and 3-15 wt.% of Ni (OH) 2 @Nb 4 N 5 or NiO@Nb 4 N 5 , wherein the surface of Nb 4 N 5 is uniformly loaded with a composite catalyst formed by Ni (OH) 2 or NiO; The preparation method of the Nb 4 N 5 loaded Ni-based active material magnesium-based hydrogen storage material comprises the following steps: S1, dissolving NbCl 5 in absolute ethyl alcohol, stirring until the solution is clear, then adding ammonia water, stirring, reacting, centrifuging to obtain a precipitate, adding deionized water into the precipitate for dissolving, then placing the precipitate into a blast drying box for hydrothermal reaction, centrifuging to obtain a precipitate, centrifugally washing with deionized water, and freeze-drying to obtain a Nb 4 N 5 precursor, wherein the hydrothermal reaction condition is that the reaction is carried out for 12-36 hours at 180-250 ℃ in a reaction kettle; S2, performing programmed temperature nitridation on the Nb 4 N 5 precursor prepared in the step S1, putting the precursor into a ceramic crucible, introducing ammonia gas into a tube furnace for calcination to obtain a Nb 4 N 5 catalyst, wherein the temperature-rising nitridation parameters are specifically that the temperature-rising rate is increased to 600-900 ℃ at 2-10 ℃ per minute, and the calcination is performed for 2-8 hours; S3, dissolving NiCl 2 •6H 2 O in deionized water to obtain a solution 1, stirring and ultrasonically treating the Nb 4 N 5 catalyst and the deionized water in the step S2 to obtain a solution 2, adding the solution 1 into the solution 2, stirring and reacting in a water bath, adding ammonia water to adjust the pH to 8-12, centrifugally washing the precipitate with the deionized water and absolute ethyl alcohol, drying to obtain a Ni (OH) 2 @Nb 4 N 5 catalyst, and calcining the Ni (OH) 2 @Nb 4 N 5 catalyst in an argon atmosphere to obtain a NiO@Nb 4 N 5 catalyst; And S4, mixing the Ni (OH) 2 @Nb 4 N 5 catalyst or the NiO@Nb 4 N 5 catalyst obtained in the step S3 with MgH 2 powder, and performing mechanical ball milling under an argon atmosphere to obtain the Ni (OH) 2 @Nb 4 N 5 -MgH 2 magnesium-based hydrogen storage material.
2. 2. The Nb 4 N 5 -loaded Ni-based active material magnesium-based hydrogen storage material according to claim 1, wherein in the step S1, the mass volume ratio of NbCl 5 , absolute ethyl alcohol and ammonia water is 0.5-1:5-20:8-60:g/mL, the concentration of the ammonia water is 4-25%, and the stirring reaction condition is that stirring reaction is carried out at a speed of 200-800 rpm for 1-10 h.
3. 3. The Nb 4 N 5 -loaded Ni-based active material magnesium-based hydrogen storage material according to claim 1, wherein in the step S3, the molar volume ratio of Nb 4 N 5 、NiCl 2 •6H 2 O to deionized water is 1:1-5:50-150, mol:L, the stirring reaction condition is that stirring reaction is carried out at a speed of 200-800 rpm for 10-60 min, the stirring reaction condition of a water bath kettle is that stirring reaction is carried out at a speed of 200-800 rpm for 1-10 h in a water bath kettle at a temperature of 40-80 ℃, the centrifugal washing condition is that centrifugal washing is carried out for 3-5 times at a speed of 3000-800 rpm by deionized water/absolute ethyl alcohol, and the drying condition is that vacuum drying is carried out at 60-100 ℃ for 8-16 h.
4. 4. The Nb 4 N 5 loaded Ni-based active material magnesium-based hydrogen storage material according to claim 1, wherein the mechanical ball milling is performed by adopting stainless steel balls, argon is used as ball milling atmosphere, the ball-material ratio is 10-40:1, the ball milling time is 5-12 h, the ball milling rotating speed is 350-500 rpm, and the reverse rotation intermittent ball milling is performed, wherein the direction is turned once after each ball milling time is 5-30 min.
5. 5. The use of the magnesium-based hydrogen storage material of claim 1 in solid state hydrogen storage.

Description

Nb 4N5 loaded Ni-based active substance magnesium-based hydrogen storage material and preparation method and application thereof Technical Field The invention belongs to the field of hydrogen storage materials, and relates to a magnesium-based hydrogen storage material loaded with Ni-based active substances by Nb 4N5, and a preparation method and application thereof. Background With the advent of the "two carbon" target, the development of the hydrogen energy industry has been of great concern. The hydrogen storage and transportation technology is a key bottleneck for realizing the large-scale and practical application of hydrogen energy, and the magnesium-based solid hydrogen storage material has wide development prospect due to the advantages of high capacity, low price, environmental protection and the like, but still has the limitations of slow dynamics, over-stable thermodynamics and poor cycle performance. In order to effectively improve the hydrogen storage performance of MgH 2, various methods have been proposed for carrying out modification research on the MgH 2 system, such as alloying, nanocrystallization, doping catalysis, compounding and the like. The invention aims to solve the key problems of high hydrogen absorption and desorption temperature, slow dynamics, poor cycle performance and the like of MgH 2 by doping a double transition metal catalyst, namely, the method realizes the rapid hydrogen absorption and desorption dynamics at low temperature and simultaneously keeps the good cycle stability of a composite system. In general, the catalytic effect of the single metal element has limitation, and the synergistic catalytic effect of the double metal elements can make the advantages of the two complementary, but the types, the combination modes, the phase results and the like of the double metal elements have different influence rules on the synergistic catalytic effect. The transition metal nitride has stable chemical property, no capacity loss to the composite system, good circulation stability, but relatively limited low-temperature hydrogen release performance. The introduction of Ni proves that the MgH 2 has great effect on improving the hydrogen storage performance, and can form Mg 2Ni/Mg2NiH4 in the hydrogen absorption and desorption process, so that the effect of a hydrogen pump is achieved, and the MgH 2 can realize reversible absorption and dehydrogenation under the lower temperature condition. Meanwhile, research proves that the synergic catalysis of the front transition metal and the rear transition metal can lead MgH 2 to obtain excellent comprehensive performance. Based on this, the present invention decided to introduce Ni-based active material on the basis of the transition metal nitride Nb 4N5 catalyst. Although Ni is a common catalyst element, no related research report on catalytic modification of MgH 2 by hydroxide exists at present, and due to high reaction activity of hydroxide, the hydroxide can synchronously react to generate catalytic active substances in the ball milling process, so that the catalyst has excellent catalytic effect, and meanwhile, the catalyst preparation process is simpler, and the cost is saved. CN114477082a discloses a hydrogen storage material of nano Ni-Nb-O doped with magnesium hydride, the nano Ni-Nb-O has a multivalent chemical environment and a "hydrogen pump" effect, and can effectively improve the hydrogen storage performance of MgH 2. However, the structure is relatively single, a multilayer structure is lacking to further improve the catalytic effect, and the two-step solvothermal method and the calcination method of the preparation method of the nano Ni-Nb-O are relatively complex in process and high in cost. The hydrogen storage material of the nano Ni-Nb-O doped magnesium hydride has lower cycle times and hydrogen storage amount retention rate. Disclosure of Invention In view of the above, the present invention aims to provide a material for catalyzing Mg/MgH 2 hydrogen storage based on Nb 4N5 -loaded Ni (OH) 2 doping, wherein Nb 4N5 has both the functions of a carrier and a catalyst. When the Ni (OH) 2 is used as a carrier, the Ni (OH) 2 has a stable structure and a large specific surface area, and can provide rich nucleation sites for the loading of the Ni (OH) 2, so that the Ni (OH) 2 obtained by the loading is fine and uniformly dispersed; when used as a catalyst, the catalyst has good catalytic action and has synergistic catalytic action with the Ni-based active substances on the surface. The synergistic catalytic effect of Ni (OH) 2 or NiO and Nb 4N5 significantly improves the hydrogen absorption and desorption performance and the cycle stability of the hydrogen storage material. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention provides a magnesium-based hydrogen storage material loaded with Ni-based active substances by Nb 4N5, which consists of MgH 2 and any