JPS5857266A - Manufacture of air electrode - Google Patents

Abstract

PURPOSE:To obtain an air electrode, in which a phthalocyanine compound of a transition metal homogeneously adheres to a carbonic body, by impregnating the carbonic body with an aqueous solution in which an amino acid salt of the said transition metal and a phthalocyanine precursor are dissolved, and subjecting the carbonic body impregnated with the solution to heat treatment. CONSTITUTION:A carbonic body is impregnated with an aqueous mixture solution, which consists of a water solution of a phthalocyanine precursor such as 1,3-dimino isoindolenine and a water solution of an amino acid salt of a transition metal such as an iron salt of bis (beta-hydroxyethyl) glycine, by a dipping method or something similar. After that, the carbonic body impregnated with the solution is dried, and heated so as to make the phthalocyanine compound of the above transition metal to homogeneously adhere to the carbonic body, thereby obtaining an air electrode. The air electrode obtained by the means mentioned above has an excellent polarization characteristic since a large amount of the metal phthalocyanine adheres homogeneously to the carbonic of the electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an air electrode used in an air cell, a fuel cell, etc., and more specifically to a method for adding a catalyst to a carbon body.

Conventionally, air electrodes such as air cells and fuel cells.

Catalysts such as metal phthalocyanine have been used to enhance the oxygen reduction ability of activated carbon, etc. However, metal phthalocyanine is insoluble in water, so it dissolves in organic solvents such as quinoline until it reaches saturation. Activated carbon was immersed in a solution, the top was dried, and the organic solvent was scattered to cause metal phthalocyanine to adhere to the activated carbon surface as a catalyst. However, metal phthalocyanine has a small amount of saturated solubility, so it is difficult to perform the above operations. I had to repeat it several times. or.

Since a special organic solvent is used, it is necessary to use expensive equipment for drying, and furthermore, the vapor of the organic solvent that evaporates and scatters poses a safety problem.

Therefore, some attempts have been made to solve the above problem by attaching a water-soluble group such as a sulfophyl group to metal phthalocyanine to make it soluble in water, but the amount of metal phthalocyanine attached to carbon bodies is still insufficient. It wasn't.

The present inventors did not directly attach metal phthalocyanine to the carbon body, but utilized the fact that amino acid salts and phthalocyanine precursors are soluble in water, and by impregnating the carbon body with these, the metal 7 If you let Tarosiani 7 do it.

=2- The amount of metal phthalocyanine attached to the carbon body also increases.

Moreover, based on the idea that it would adhere uniformly, the present invention was finally completed as a result of intensive research.

Namely, in the present invention, a carbon body is impregnated with an aqueous solution in which an amino acid salt of a transition metal is dissolved and an aqueous solution in which a phthalocyanine precursor is dissolved, and then heat-treated to cause the phthalocyanine of a transition metal to adhere to the carbon body. The gist of the present invention is a method for manufacturing an air electrode characterized by the following.

According to the production method of the present invention, by impregnating a carbon body with an aqueous solution of an amino acid salt of a transition metal and an aqueous solution of a phthalocyanine precursor, the surface of the carbon body and its pores can be easily filled with the amino acid salt of a transition metal and phthalocyanine. By adsorbing or penetrating the precursor, heat treatment, and reduction as necessary, the transition metal 7-talocin-7 is stoichiometrically adhered to the rR element surface and pores uniformly and in large quantities. It is assumed that there are.

Below, nine aspects of the present invention will be explained in detail.

6. Carbon bodies used in the present invention include commonly used carbon blacks such as furnace black, channel black, and thermal black, as well as wood, charcoal, coconut shell charcoal, and palm kernel charcoal.

Examples include one or a mixture of two or more of activated carbon and graphite made using coal, petroleum residue, synthetic resin, organic waste, etc., and extrusion molding, injection molding,
It is made into a fixed shape by pressure molding or the like.

Amino acid salts of transition metals can be produced by adding water-soluble gold VA salts of transition metals such as nickel, cobalt, chromium, iron, and copper and alkali metal salts such as amino acids having a β-hydroxyethyl group represented by the following structural formula. easily obtained. for example.

Add cupric chloride aqueous solution to an aqueous solution of sodium salt of bis(β-hydroxyethyl)glycine.

Concentrating the solution yields bis(β-human p-xyethyl)green copper as dark blue crystals.

4- (Glycine derivative) (Glycine derivative) (Sarcosine derivative) (Alanine derivative) (7 la; = >elf; 4
k) (Serine derivative) 5- () (D C? (J 0) (J) group CHJ CHjS
QJ H (taurine derivative) As the phthalocyanine precursor, 1,3-cy, noisoindolenine or its derivative JP.

1.1-Dialkoxy-6-imitsuisoindolenine can be used, and specific examples include those represented by the following structural formula.

Buttock H 1 ( H (1,3-diiminoindolenine) H 1 (derivative of 1,3-diiminoindolenine) 6- -〇H YuC-HJQ) ( 11 (1,S-diiminoindolenine) M conductor of indolenine) NCH
.

1 1 QI-II (derivative of 1,3-diiminoisoindolenine) 7-4 (+,1-jetoxy 3-iminoisoindolenine)
+1 N (1.1-bis(β-oxyethquin)-5-iminoisoindolenine) The amount of this phthalocyanine precursor to be used is preferably 1 to 50%, particularly 5 to 20%, based on the carbon body. is preferred.

or. Use of amino acid salts of transition metals i7t3 lid Gl'
The molar ratio of the phthalone anino precursor to the transition metal amino acid salt τ4 to the y7dyne4ff structure is preferably 158-2.

When manufacturing the air electrode, the phthalocyanine precursor and the amino acid metal salt are dissolved in a 5% aqueous solution of the lid precursor described above (depending on the type of phthalocyanine precursor, alcohol or glycol may be used as appropriate). ．． The carbon body was immersed in this solution. Dry it at room temperature and heat it at 150℃, or
Add a reducing agent such as hydroquinone or hydradun to the solution.
% and heated to 80℃. Metal phthalocyanine can be uniformly attached to the surface of the carbon body. Note that the carbon material V was immersed in an aqueous solution of a phthalone 7-nin precursor or an it-amino acid metal salt. After drying. It may be further immersed in the remaining aqueous solution.

below. The present invention will be explained in more detail with reference to Examples. In the examples, "part" indicates "overlapping part".

Example 1 10 parts of active coconut shell #2 with particle size α1~1μ, 10 parts of graphite with particle size 9-01~05μ, and 5 parts of thermoplastic resin (vinyl chloride resin) were mixed and extrusion molded to produce a A round bar was made and then heated to 200°C to decompose the thermoplastic resin and form a carbon body.

This carbon body is 5% of 1.5-diaminoisoindolenine.
Aqueous solution and N,N-bis(β-hydroxyethyl)gly7
After soaking in an aqueous solution of iron salt (1.5 moles for 4 moles of 1.3-diaminoindorene) and an aqueous solution of 9! Dry in a stream of air. By heating the dried carbon body at 150°C for 10 minutes. An air electrode was obtained in which iron phthalocyanine was uniformly deposited on the surface of a carbon body.

Example 2 10 parts of coconut shell activated carbon with a particle size of 0.1-1μ, particle size 01-0
10 parts of 5μ graphite. Thermoplastic resin (Hylic chloride resin) 1
Eight parts were pressure-molded to form a square bar with a cross section of 10 x 10 squares, and then heated to 200°C to decompose the thermoplastic resin and form a carbon body.

This carbon body is 1-bis(β-hydroxyethyl)-3-
5% aqueous solution of iminoisoindolenine and cobalt salt of N-β-hydroxyethylsarcosine (amount to be 1.5 mol per 4 mol of 1-bis(β-hydroxyethyl)-3-7minoisoindolenine) ) and then dried in a stream of air at room temperature. Is it dry? , :
By heating the carbon body at 150° C. for 10 minutes, an air electrode was obtained in which cobalt phthalocyanine was uniformly adhered to the surface of the i element body.

Comparative Example 1 Carbon weight sulfonated iron phthalocyanine 5 of Example 1
% aqueous solution and then dried in a stream of air at room temperature. By heating the dried carbon body at 150° C. for 10 minutes, an air electrode 7 having iron phthalocyanine adhered to the surface of the carbon body was obtained.

Examples 1 and 2 above. The polarization curve of the air electrode obtained in Comparative Example 1 is shown in FIG.

As described in F below, the air electrode obtained by the manufacturing method of the present invention has excellent polarization characteristics because the metal phthalocyanine is uniformly and in large numbers adhered to the surface of the carbon body.

[Brief explanation of drawings]

FIG. 1 shows examples 1 and 2. These are the polarization curves of the air electrode obtained in Comparative Example 1, and ■ to ■ are the polarization curves of Example 1. Example 2. It shows the polarization curve obtained in Comparative Example 1, where the vertical axis is current density (mA/cd). The horizontal axis indicates the potential (V/SCE). Patent applicant Pentel Co., Ltd.

Claims (1)

[Claims] Manufacture of an air electrode characterized in that a carbon body is impregnated with a solution of an amino acid salt of a transition metal dissolved therein and an aqueous solution of a butalocyanine precursor dissolved therein, and heat treated to adhere a phthalocyanine of a transition metal to the carbon body. Method.