JP-7855183-B2 - Carbon materials, methods for producing carbon materials, catalysts, dispersions, electrodes, batteries, and electrolysis apparatuses.

JP7855183B2JP 7855183 B2JP7855183 B2JP 7855183B2JP-7855183-B2

Inventors

坂本圭亮
安井健悟
白石康浩
平井隆之

Assignees

ＤＩＣ株式会社
国立大学法人大阪大学

Dates

Publication Date: 20260508
Application Date: 20240321
Priority Date: 20230406

Claims (13)

It contains a calcined product of a phthalocyanine compound having bromine and chlorine as substituents, The phthalocyanine compound contains Fe, Co, Ni, Cu, or Zn as the central metal. The average bromine number of the phthalocyanine compound is 4 or more and less than 16. The average number of chlorine atoms in the phthalocyanine compound is greater than 0 and 11 or less. The average halogen number of the phthalocyanine compound is 8 or more and 16 or less. The average particle size is 0.01 to 1 μm. A carbon material with a BET specific surface area of 100 to 2000 m² /g.
The carbon material according to claim 1, wherein the phthalocyanine compound contains Fe, Co, or Zn as the central metal.
The carbon material according to claim 1, wherein the phthalocyanine compound contains Zn as the central metal.
The phthalocyanine compound is in powder form, The carbon material according to claim 1, wherein the average particle size of the powder comprising the phthalocyanine compound is 300 nm or less.
A method for producing a carbon material according to any one of claims 1 to 4 , A method for producing a carbon material, comprising the step of calcining a raw material containing the phthalocyanine compound at 600 to 1500°C.
A catalyst used in the four-electron reduction reaction of oxygen, comprising a carbon material according to any one of claims 1 to 4 .
A catalyst used in the two-electron reduction reaction of oxygen, comprising a carbon material according to any one of claims 1 to 4 .
A dispersion comprising a carbon material according to any one of claims 1 to 4 and a dispersion medium for the carbon material.
The dispersion according to claim 8 , comprising a polymer electrolyte.
An electrode comprising an electrode catalyst layer containing the carbon material described in any one of claims 1 to 4 .
The electrode according to claim 10 , wherein the electrode catalyst layer contains a polymer electrolyte.
A battery comprising the electrode described in claim 10 .
An electrolysis apparatus comprising the electrodes described in claim 10 .

Description

This invention relates to carbon materials, methods for producing carbon materials, catalysts, dispersions, electrodes, batteries, and electrolysis apparatus. Carbon materials are used in a wide range of applications due to their properties such as high electrical conductivity, high thermal conductivity, low thermal expansion coefficient, lightness, and heat resistance. In recent years, the use of nitrogen-containing carbon materials as oxygen reduction catalysts has been investigated. For example, applications have been proposed for catalysts for the positive electrodes of fuel cells and air batteries, utilizing their function as a four-electron reduction catalyst that catalyzes the four-electron reduction reaction of oxygen, and for catalysts for the cathodes of electrolysis devices (hydrogen peroxide synthesis devices), utilizing their function as a two-electron reduction catalyst that catalyzes the two-electron reduction reaction of oxygen (see, for example, Patent Document 1). Japanese Patent Publication No. 2012-101155International Publication No. 2021/220495 In this specification, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. Furthermore, unless otherwise explicitly stated, the units of the numbers before and after "~" are the same. In numerical ranges described in stages within this specification, the upper or lower limit of one stage of the range may be replaced with the upper or lower limit of another stage. Also, in numerical ranges described within this specification, the upper or lower limit of that range may be replaced with the values shown in the examples (experimental examples). Furthermore, individually described upper and lower limits can be combined in any way. Preferred embodiments of this disclosure are described below. However, this disclosure is not limited to the embodiments described below. <Carbon materials> One embodiment of the present disclosure is a carbon material comprising a calcined product of a phthalocyanine compound having bromine (Br) as a substituent (hereinafter also referred to as a "brominated phthalocyanine compound"). The above carbon material, containing a calcined product of a brominated phthalocyanine compound, exhibits excellent oxygen reduction activity. Therefore, this carbon material can be used as a catalyst for oxygen reduction reactions (oxygen reduction catalyst), and is used, for example, as an electrode catalyst such as a positive electrode catalyst for fuel cells and air batteries, or a negative electrode catalyst for oxygen electrolysis devices. The oxygen reduction activity of the carbon material can be confirmed by the method described in the examples (experimental examples). The calcined product may be a calcined product obtained by calcining one type of brominated phthalocyanine compound, or it may be a calcined product obtained by calcining multiple types of brominated phthalocyanine compounds. Brominated phthalocyanine compounds have a structure represented by, for example, the following formula (1) or formula (2). In formulas (1) and (2), X1 to X16 each independently represent a hydrogen atom or a halogen atom, provided that at least one of X1 to X16 is a bromine atom. In formula (2), M represents the central metal. Examples of central metals (M) include Fe, Co, Ni, Cu, and Zn. Phthalocyanine compounds containing a central metal are sometimes referred to using a prefix corresponding to the type of central metal, such as "iron phthalocyanine" (central metal: Fe), "cobalt phthalocyanine" (central metal: Co), "copper phthalocyanine" (central metal: Cu), and "zinc phthalocyanine" (central metal: Zn). The brominated phthalocyanine compound does not necessarily have the above-mentioned central metal (M), but when the brominated phthalocyanine compound has the above-mentioned central metal (M), superior oxygen reduction activity is more likely to be obtained. From the viewpoint of obtaining even superior oxygen reduction activity, the brominated phthalocyanine compound may contain Fe, Co, or Zn as the central metal (M), and from the viewpoint of obtaining even superior oxygen reduction activity, it may contain Zn. The halogen atom may consist solely of a bromine atom, or it may be a combination of a bromine atom and other halogen atoms (fluorine, chlorine, and iodine atoms). The halogen atom may contain both a bromine atom and a chlorine atom. Among brominated phthalocyanine compounds, phthalocyanine compounds having bromine and chlorine as substituents and Zn as the central metal (brominated zinc chloride phthalocyanine) tend to yield even better oxygen reduction activity. The average number of bromine atoms in a brominated phthalocyanine compound, that is, the average number of bromine atoms in the brominated phthalocyanine compound (the number of bromine atoms per molecule), should be greater than 0, and from the viewpoint of easily obtaining