JPS60230950A - Hydrogen storing material - Google Patents

Abstract

PURPOSE:To increase the amount of hydrogen stored at ordinary temp. under low pressure and to improve the efficiency of energy conversion by blending a rare earth metal with Ni, Sn and Al, Mn, Co or the like in a ratio represented by a general formula. CONSTITUTION:This hydrogen storing material contg. Sn is represented by formula I (where R is a rare earth metal or a mixture of rare earth metals, x= 4.8-5.5, and a=0.01-1), formula II (where A is Al, Mn, Co, Fe, Cr, V, Nb, Ti or Cu, x=4.8-5.5, and a, b=0.01-1) or formula III (where A and B are different metals selected among Al, Mn, Co, Fe, Cr, V, Nb, Ti and Cu, x=4.8-5.5, and a, b, c=0.01-1). The material stores a large amount of hydrogen at ordinary temp. under low pressure, and it is utilized for energy conversion in a heat pump or the like and shows superior efficiency of energy conversion.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to hydrogen storage materials with excellent conversion efficiency or sensitivity used for energy conversion such as heat pumps or temperature sensors, particularly R metal (rare earth metal)-N1 type hydrogen storage materials. Regarding hydrogen storage materials.

(Problems to be solved by the invention) The amount of hydrogen stored is large at relatively low pressure at room temperature, and there is a difference between the absorbed hydrogen pressure and the dissociation equilibrium pressure (so-called hysteresis).
The objective is to provide a small hydrogen storage material.

(Prior art) Ti-F8 alloy and LaNi5 are conventional hydrogen storage materials.
Also, MmN15 (Mm is Mitsu7yu metal) alloy or M
Various materials made of alloys and the like have been proposed.

However, metal La2Mm (Ce40~50%, La
25-35%, mixture of other metals such as Nd, Pr, Sm) or Mm with a large amount of La (40-70% La, Ce
A mixture of O, 1 to 20% and other metals such as Nd, Pr, and Sm. LaNi5. M
Although the material made of mNi5°LmN15 has the advantage of having a large hydrogen storage capacity and a relatively fast absorption/desorption rate, it has the problem of large hysteresis.

Ushida, MmNl, is LaN13 because La is expensive.
Although it was developed to improve the economic efficiency of the system, it has the disadvantages of large hysteresis and high storage pressure, and is difficult to use.

Conventionally, La was used to control storage pressure and improve hysteresis.
N1. Alternatively, it has been proposed to add a third element such as Az or a fourth element to a material made of an MmN1 alloy, but in this case, it is effective in reducing the occlusion and desorption pressure, but it does not necessarily improve the hysteresis. There wasn't enough sushi either.

(Means for Solving the Problems) The present invention provides a hydrogen storage material using the general formula % (where R is a rare earth metal or a mixture of rare earth metals:
is 4.8-5.5, a is o, o 1-1.0), and the general formula % formula % (21 (However, I RI Same as invention.A is Az
, Mn, Co, Fo, C,, V, Nb, T1 or Cu.

a and b are respectively 0.01-1.0'). It is a hydrogen storage material containing hydrogen storage material, and also has the general formula % (where R, x, A are the same as the general formula (2) above, and B
are Az, Mn, Co, Fe, Cr, V, Nb, T1. C
It is an Sn-containing hydrogen storage material, where u is a metal different from A, and a, b, and c are each 0.01 to 10°.

(Effects) In the present invention, R may be not only the above-mentioned M but also Lm, 1 or a. However, considering manufacturing costs and the like, it is desirable to use Mm or Lm.

The hydrogen storage material of the present invention is the above-mentioned R1 metal N.

The hydrogen storage material of the specified invention can be easily obtained by heating and melting and granular S in an inert atmosphere such as argon in a known high frequency furnace or tungsten electrode arc melting furnace, followed by appropriate heat treatment and pulverization. I can do it, and also At.

1 of M, , Co, Fe, C, , V, Nb, T1 or Cu
Hydrogen storage materials of the general formulas (2) and (3) can also be easily obtained by adding one species or two species.

S in the present invention. If the amount of addition is less than 0.01, there is no effect of reducing hysteresis, while if it is more than 1.0, the amount of hydrogen storage decreases due to the addition of Sn, so 0.0
The range is 1 to 1.0.

In addition, the specified invention RxN1(x-a)SnaKAt
.

Hysteresis can be improved by adding a fourth element such as M, Co, Fe, Cr, V, Nb, T1 or Cu, or a fourth element and a fifth element.
If the content of the element and the fifth element is less than 0.01, the storage pressure cannot be improved, and if it is still more than 1.0, the amount of storage will decrease. Therefore, both the A element and the B element are in the range of 0.01 to 1.0.

However, if X in the above general formula (+1, (21 and (3)) is larger than 5.5 or smaller than 4.8, not only will the hydrogen storage capacity decrease, but the hydride will become unstable and hydrogen It is necessary to keep the value in the range of 4.8 to 55, since the material is likely to deteriorate due to repeated occlusion and release of .

Next, manufacturing examples of the present invention will be explained, and the effects thereof will also be explained.

Production Example 1 Using L as R, predetermined amounts of metal N1 and granular Sm were heated and melted in an arc melting furnace under an argon atmosphere to obtain LmN149Sno, LmN, 48Sno2 and L
N S was prepared and heated at 1050°C for 8 hours.
．． After heat treatment for 7 nO, 3 minutes, it is ground into 9 to 100 meshes in the air. For comparison, LmN, 5°Lr1INi
49 Ato+ and LmN148Ato2 were prepared as described above.

Production Example 2 Using La as R, metal N1 and granular Sn were treated in the same manner as in Production Example 1 to produce LaNi4□5no3. For comparison, LaN13 was treated in the same manner as above.
and La Ni 4.7Ato,a were produced.

Production Example 3 Mm was used as R and treated in the same manner as in Production Examples 1 and 2 to produce MmN14°5no3 and MmNi5 and MmN14□Ato3 for comparison.

Production example 4゜ Lm and Mm are used as R, and metal Ni is added thereto.

Granular S and M as an element in general formula (2). lCQ
LmNi 4.4Sno, +Mn
O, 51LmNitaSno3Coo3 and MmN1
465Sno3■oo52MmN146Soo2Am2
was manufactured.

Similarly, M is substituted for element A in general formula (3). , C to B element
LmNi<4sSno, +Mno4COo, o5
and LmN1455Moo4Cooo5 for comparison.
was manufactured.

The pulverized products produced in Production Examples 1 to 4 are sealed in a reaction vessel, and the interior of the vessel is purged with hydrogen gas at room temperature to activate the vessel with a hydrogen pressure of 30 kV/ca.

Next, after exhausting the stored H2, the H2 at 30°C is
The absorption and release amounts and their equilibrium pressures were measured, and the results shown in Table 1 were obtained.

As is clear from Table 1, the present invention in which Sn is added has a lower hysteresis factor "n (Pa/P
dρ has been greatly improved, and the storage pressure (Pa),
It was recognized that the discharge pressure (Pd) was also significantly improved, and the maximum storage amount of H2 ((H/M)max) was also found to be comparable to that of the comparative example.

As described above, in the present invention, any of the conventional Mm, Lm, or La can be used by adding Sn to the R-Ni alloy, and in any case, the hysteresis is reduced, so the energy consumption of heat pumps, etc. When used for conversion, the conversion efficiency is improved, and when used as a temperature sensor, the sensitivity is improved, making it possible to provide a hydrogen storage material with excellent performance.

Patent Applicant Japan Heavy Chemical Industry Co., Ltd. Agent Rikichi Ichikawa Procedural Amendment (Spontaneous) June 11, 1980 Commissioner of the Patent Office Kazuo Wakasugi Toronyo (Patent Office Examiner) 1. Indication of the case 1988 Patent Application No. 88058 2, title of the invention, hydrogen storage material specification, page 1, line 9: ``Or CuoJ'' or one type of Cu.

” he corrected.

that's all

Claims (3)

[Claims] (1) General formula RN1(x-a) Soa (where R is a rare earth metal or a mixture of rare earth metals; x
is 4.8 to 5.5. Sn-containing hydrogen storage material, where a is 0.01 to 1.0°). (2) General formula RNi (x-a-b) 5naAb (where, R is a rare earth metal or a mixture of rare earth metals; A is A
z, Mn, Co, Fe, C,,V. One of Nb, T1 or Cu; X is 4.8-5.5. a
. b is 0.01 to 1.0). Containing hydrogen storage material. (3) General formula RNi(x-a-b-c)SnaAbB
c (where R is a rare earth metal or a mixture of rare earth metals;
A and B are At2Mn, co, and Fe, respectively. CI + V + Nl) + Ti + Cu,
and A and B are different metals; X is 4.8-5.5,
8n-containing hydrogen storage material, where a, b, and c are each 0.01 to 1.0.