阅读说明：本技术 一种金属氨基硼烷复合储氢材料 (Metal amino borane composite hydrogen storage material ) 是由 武媛方 刘晓然 王树茂 蒋利军 李志念 叶建华 袁宝龙 郭秀梅 于 2020-06-11 设计创作，主要内容包括：本发明公开了属于固态氢气储存材料技术领域的一种金属氨基硼烷复合储氢材料。所述金属氨基硼烷复合储氢材料由α-LiNH<Sub>2</Sub>BH<Sub>3</Sub>相、LiH相和储氢合金氢化物相组成,以LiH、NH<Sub>3</Sub>BH<Sub>3</Sub>和储氢合金为原料经原位金属化复合球磨制备而成,NH<Sub>3</Sub>BH<Sub>3</Sub>、LiH、储氢合金的摩尔比为1:(1.01～1.05):(0.1～0.5)。所述金属氨基硼烷复合储氢材料相较于氨硼烷、金属氨硼烷可在室温附近快速放氢、具有更快的放氢动力学、无杂质气体产生,且具有制备工艺简单、效率高的优点,可用于燃料电池高安全高密度固态氢源。(The invention discloses a metal amino borane composite hydrogen storage material, belonging to the technical field of solid hydrogen storage materials, wherein the metal amino borane composite hydrogen storage material is prepared from α -LiNH 2 BH 3 Phase, LiH phase and hydride phase of hydrogen storage alloy consisting of LiH, NH 3 BH 3 And hydrogen storage alloy as raw material, and in-situ metallizing and ball-milling to obtain NH 3 BH 3 The molar ratio of LiH to the hydrogen storage alloy is 1 (1.01-1.05) to 0.1-0.5. Compared with ammonia borane and metal ammonia borane, the metal amino borane composite hydrogen storage material can rapidly release hydrogen at room temperature, has faster hydrogen release kinetics, does not generate impurity gas, has the advantages of simple preparation process and high efficiency, and can be used for high-safety high-density solid hydrogen sources of fuel cells.)

1. The metal amino borane composite hydrogen storage material is characterized in that the raw material is NH₃BH₃A composite ball milled product of LiH and a hydrogen storage alloy; wherein NH₃BH₃The molar ratio of LiH to the hydrogen storage alloy is 1 (1.01-1.05) to 0.1-0.5;

the hydrogen storage alloy is TiMn₂One or two of Ti-V hydrogen storage alloy and Ti-Fe hydrogen storage alloy.

2. The material of claim 1, wherein the metal amino borane composite hydrogen storage material is obtained by an in-situ metallization compounding method, the raw material is subjected to ball milling in a hydrogen atmosphere, the atmosphere pressure is 8-10 bar, the ball-material ratio is 50:1, the ball milling rotation speed is 0-400 r/min, the accumulated ball milling time is 8-10 h, and the temperature of a ball milling tank is regulated and controlled to be less than or equal to 30 ℃ by adopting temperature and pressure monitoring and ball milling rotation speed.

3. The material of claim 1, wherein the metal aminoborane composite hydrogen storage material is formed from α -LiNH₂BH₃Phase, LiH phase and metal hydride phase.

4. A material according to any one of claims 1 to 3, wherein the metallic aminoborane composite hydrogen storage material emits more than 5 wt% hydrogen at 50 ℃ for 30 min.

Technical Field

The invention belongs to the technical field of solid hydrogen storage materials, and particularly relates to a metal amino borane composite hydrogen storage material.

Background

Hydrogen plays an important role in the current global energy system, and a light-weight high-capacity solid-state hydrogen storage material can meet the requirements of safe storage and transportation of hydrogen. However, in the practical application process, these solid hydrogen storage materials often have temperatures of high hydrogen discharge temperature and small hydrogen discharge capacity, which is difficult to meet the requirements of practical production. Therefore, a method for preparing a solid hydrogen storage material with high capacity and mild hydrogen discharge conditions is needed to meet the application requirements of the hydrogen storage material in the field of fuel cells.

Currently, ammonia borane, as representative of chemical hydrogen storage materials, inherently has a mass hydrogen storage density of up to 19.6 wt%, and a volumetric hydrogen storage density of 146gH₂L, the initial hydrogen discharge temperature is about 75 ℃, and 12.5 wt% of hydrogen can be discharged at 150 ℃; meet a number of on-board hydrogen storage technology goals for light-duty fuel cell vehicles set forth by the U.S. DOE in 2015. However, in order to be used in practical production and application, the existing method for improving the hydrogen release performance of ammonia borane is to synthesize metal aminoborane by adding alkali/alkaline earth metal hydride, but the hydrogen release temperature of the hydrogen storage system obtained by the method is still high, and a small amount of NH still exists in the hydrogen release product₃、B₂H₆And the like. In addition, the catalytic hydrogen release effect is achieved by adding transition metal and alloy thereof, but the catalytic additive does not participate in the hydrogen release of the system, so that the problems of reduced hydrogen storage density and slow hydrogen release kinetics are caused.

Disclosure of Invention

Aiming at the problems, the invention provides a metal amino borane composite hydrogen storage material, wherein the raw material is NH₃BH₃A composite ball milled product of LiH and a hydrogen storage alloy; wherein NH₃BH₃The molar ratio of LiH to the hydrogen storage alloy is 1 (1.01)～1.05):(0.1～0.5)；

The hydrogen storage alloy is TiMn₂One or two of Ti-V hydrogen storage alloy and Ti-Fe hydrogen storage alloy.

The metal amino borane composite hydrogen storage material is obtained by adopting an in-situ metallization compounding method, the raw materials are subjected to ball milling in a hydrogen atmosphere, the atmosphere pressure is 8-10 bar, the ball-material ratio is 50:1, the ball milling rotation speed is 0-400 r/min, the accumulated ball milling time is 8-10 h, and the temperature of a ball milling tank is regulated to be less than or equal to 30 ℃ by adopting temperature and pressure monitoring and ball milling rotation speed regulation.

The metal amino borane composite hydrogen storage material is prepared from α -LiNH₂BH₃Phase, LiH phase and metal hydride phase.

The metal amino borane composite hydrogen storage material can release more than 5 wt% of hydrogen in 30min at 50 ℃.

The phase design of the metal amino borane composite hydrogen storage material comprises that the metal amino borane composite hydrogen storage material is composed of α -LiNH₂BH₃Phase, small amount of LiH phase and metal hydride phase, pure α -LiNH₂BH₃Compared with α, β composite phase, the phase has better hydrogen evolution kinetics and thermodynamics and no by-product NH₃、B₂H₆Formation, small amount of LiH phase is favorable for catalyzing α -LiNH₂BH₃Hydrogen is discharged; TiMn₂The hydrogenated phase of the hydrogen storage alloy of the series, Ti-V series and Ti-Fe series has stronger brittleness and hardness, can absorb and release hydrogen under mild conditions, greatly improves the ball milling efficiency, and is used as a hydrogen pump to promote α -LiNH₂BH₃Hydrogen is discharged;

in the preparation process, the in-situ metallization compounding of the ammonia borane is realized through hydrogen storage alloy screening, temperature and pressure monitoring in the preparation process and ball milling process regulation and control, and the decomposition and hydrogen release of the metal ammonia borane and the metal hydride in the synthesis process are inhibited.

The invention has the beneficial effects that:

1. the metal amino borane composite hydrogen storage material designed by the invention contains α -LiNH₂BH₃The phase, a small amount of LiH phase and alloy hydride phase can be rapidly released at 50 ℃, and no NH is contained in the hydrogen release product₃、B₂H₆And (c) an impurity gas of α -LiNH₂BH₃Compared with the common α and β composite phases, the low-content LiH has lower hydrogen release temperature and can promote α -LiNH₂BH₃The alloy hydride phase is used as a hydrogen pump to further accelerate the hydrogen discharge of the composite system.

2. The invention adopts an in-situ metallization compounding method, prepares and obtains the designed alloy composite phase by screening the hydrogen storage alloy with suitable hydrogen absorption and desorption platform pressure and controlling the hydrogenation pressure and temperature, and has the advantages of simple process and high preparation efficiency.

Drawings

FIG. 1 α -LiNH in example 1₂BH₃+0.1LiH and α -LiNH of comparative example 1₂BH₃And β -LiNH₂BH₃A composite XRD contrast spectrum;

FIG. 2 α -LiNH in example 1₂BH₃+0.1LiH and α -LiNH of comparative example 1₂BH₃And β -LiNH₂BH₃A DSC curve of the complex;

FIG. 3-a α -LiNH in example 1₂BH₃+0.1LiH mass spectrometry profile of the hydrogen evolution product;

FIG. 3-b α -LiNH of comparative example 1₂BH₃And β -LiNH₂BH₃Mass spectrometry of the hydrogen evolution product of the complex;

FIG. 4 α -LiNH in example 2₂BH₃-0.1LiH-0.2(V-Ti-Cr)H_xA composite system XRD spectrum;

FIG. 5 α -LiNH in example 2₂BH₃-0.1LiH-0.2(V-Ti-Cr)H_xThe composite system hydrogen evolution kinetics curve at 50 ℃;

FIG. 6 α -LiNH in example 2₂BH₃-0.1LiH-0.2(V-Ti-Cr)H_xMass spectrum analysis chart of composite system hydrogen evolution product

Detailed Description

The invention is described in further detail below with reference to the following figures and specific examples: