Carbon support, metal-supported catalyst, electrode, and battery

Abstract

To provide a carbon carrier which achieves effective maintenance of performance of a metal-supported catalyst, and to provide a metal-supported catalyst, an electrode and a battery in which performance is effectively maintained.SOLUTION: Wherein a volume of pores having pore diameters in a range of more than 77K and 0nm or less, which is obtained by a DFT method from a nitrogen-adsorption isotherm at a temperature of 70nm, is 0. 70cm3 / g or less, A volume of pores having pore diameters less than 5nm is 0. 31cm3 / g or more, a true concentration obtained by a constant volume expansion method is 1. 9g / cm3 or more, and a half width at half maximum of a D band having a peak top near a Raman shift 1340cm of - 1 is 50cm of - 1 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a carbon support, a metal-supported catalyst, an electrode, and a battery. [Background technology]

[0002] Patent Document 1 describes a catalyst comprising a catalyst support and a catalytic metal supported on the catalyst support, wherein the catalyst has pores with a radius of less than 1 nm and pores with a radius of 1 nm or more, the pores with a radius of less than 1 nm have a pore volume of 0.3 cc / g of support or more, and the catalytic metal is supported inside the pores with a radius of 1 nm or more; and a catalyst comprising a catalytic metal and a support, wherein the catalyst has pores with a radius of less than 1 nm and pores with a radius of 1 nm or more, the mode radius of the pore distribution of the pores with a radius of less than 1 nm is 0.3 nm or more but less than 1 nm, and the catalytic metal is supported inside the pores with a radius of 1 nm or more.

[0003] Patent Document 2 describes a carbon powder containing carbon as the main component, which has a BET specific surface area per weight of 900 m 2 / g or more, and is measured by Raman spectroscopy at 1580 cm -1 The G-band peak intensity (G intensity) measured near 1620 cm -1 The document describes a catalytic carbon powder having a ratio R' (D' / G intensity ratio) of the peak intensity of the D' band (D' intensity) measured around 0.6 or less.

[0004] Patent Document 3 describes an electrode catalyst for a fuel cell, which is composed of a catalyst carrier mainly composed of carbon and a catalytic metal supported on the catalyst carrier, and which is detected at 1580 cm by Raman spectroscopy. -1 The G-band peak intensity (G intensity) measured near 1620 cm -1and (b) a specific surface area of ​​the catalytic metal is 60 m or more; and (c) a specific surface area of ​​the catalytic metal is 60 m or more; and (d) a specific surface area of ​​the catalytic metal is 60 m or more; and (e) a specific surface area of ​​the catalytic metal is 60 m or more; and (f) a specific surface area of ​​the catalytic metal is 60 m or more; and (g) a specific surface area of ​​the catalytic metal is 60 m or more; and (g) a specific surface area of ​​the catalytic metal is 60 m or more; and (c) a specific surface area of ​​the catalytic metal is 60 m or more; and (d) a specific surface area of ​​the catalytic metal is 60 m or more; and (f ... 2 (c) the carrier has pores with a radius of less than 1 nm and pores with a radius of 1 nm or more, the mode radius of the pore distribution of the pores with a radius of less than 1 nm is 0.3 nm or more and less than 1 nm, and the catalytic metal is supported inside the pores with a radius of 1 nm or more; (d) the carrier has a mode radius of 1 nm or more and less than 5 nm, the catalytic metal is supported inside the pores with a radius of 1 nm or more, the mode radius is half or less of the average particle size of the catalytic metal, and the pore volume of the pores with a radius of 1 nm or more and less than 5 nm is 0.4 cc / g of carrier or more.

[0005] Patent Document 4 describes a metal-encapsulated dendritic carbon nanostructure, characterized by comprising a dendritic carbon nanostructure formed by branching rod-shaped or ring-shaped bodies containing carbon, and a metal body encapsulated in the carbon nanostructure.

[0006] Patent Document 5 describes a porous carbon having mesopores and micropores smaller than the mesopores, characterized in that the carbonaceous walls that form the outer peripheries of the mesopores have a three-dimensional network structure, the mesopores are configured to be approximately equal in size, and the micropores are formed in the carbonaceous walls at positions facing the mesopores.

[0007] Patent Document 6 describes a method for producing a cellulose membrane with a mesopore volume of 0.07 cm 3 / g) or more and a maximum differential volume value of 1.6 or more for pore diameters of 0.4 nm to 0.6 nm.

[0008] Patent Document 7 describes a porous carbon material having a nitrogen content of 0.2 to 2.0% by mass, a specific surface area of 1000 to 1800 m 2 / g obtained by the BET method of the nitrogen adsorption and desorption method, and a pore volume of 0.50 to 0.80 cm 3 / g obtained by the quenched solid density functional theory method (QSDFT) of the nitrogen adsorption and desorption method.

[0009] Patent Document 8 describes a carbon carrier for supporting catalyst metal particles, in which, in the Raman spectrum obtained by Raman spectroscopy, the ratio of the intensity of the 2D band having a peak top around 2680 cm -1 to the intensity of the G band having a peak top around 1600 cm -1 is not less than 0.36 and not more than 1.0, and the ratio of the crystallite size La obtained from the (110) diffraction line of carbon in the X-ray diffraction pattern to the crystallite size Lc obtained from the (002) diffraction line of carbon in the X-ray diffraction pattern obtained by powder X-ray diffraction using CuKα radiation is not less than 2.50.

[0010] Patent Document 9 describes a cathode electrode structure for a fuel cell, which includes a carbon catalyst and an ionomer and satisfies the following formulas (1) to (3): (1) 0.1 < X1 / Y1 ≤ 5; (2) 0.1 ≤ X2 / Y2 < 5; and (3) 1.1 ≤ (X1 / Y1) / (X2 / Y2) ≤ 5 (where when X / Y is the mass ratio of the carbon catalyst (X) to the ionomer (Y) in the electrode structure, X1 / Y1 represents X / Y on one surface of the electrode structure, and X2 / Y2 represents X / Y on the other surface of the electrode structure).

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Patent Document 2

[0012] On the other hand, in a conventional catalyst layer including a metal-supported catalyst including a carbon support and catalytic metal particles supported on the carbon support, and an electrolyte material, there has been a problem that when the amount of the electrolyte material is reduced, the performance of the metal-supported catalyst is degraded.

[0013] The present invention has been made in view of the above-mentioned problems, and one of its objects is to provide a carbon support that achieves effective maintenance of the performance of a metal-supported catalyst, as well as a metal-supported catalyst, an electrode, and a battery that effectively maintain their performance. [Means for solving the problem]

[0014] [1] A carbon support according to one embodiment of the present invention for solving the above problems is a carbon support for supporting catalytic metal particles, wherein the volume of pores having a pore diameter in the range of more than 0 nm and not more than 70 nm, as obtained by the DFT method from a nitrogen adsorption isotherm at a temperature of 77 K, is 0.70 cm 3 / g or less, and the volume of pores within a range of pore diameters of less than 5 nm obtained from the nitrogen adsorption isotherm by the DFT method is 0.31 cm 3 / g or more, and the true density obtained by the constant volume expansion method is 1.9 g / cm 3 The Raman spectrum obtained by Raman spectroscopy shows a Raman shift of 1340 cm -1 The half-width at half maximum of the D band with a peak top near 50 cm -1 It has the following carbon structure: According to the present invention, a carbon support is provided that achieves effective maintenance of the performance of a metal-supported catalyst.

[0015] [2] The carbon support of [1] may have an oxygen content of 0.5% by weight or more as determined by elemental analysis. [3] The carbon support of [1] or [2] may have a pore volume (cm) of pores with a pore diameter in the range of 5 nm to 70 nm as determined by the DFT method from the nitrogen adsorption isotherm. 3 / g) of the pores in the range of less than 5 nm in diameter. 3 / g) may be 9.0 or more.

[0016] [4] The carbon support according to any one of [1] to [3] has a pore volume of 1.00 cm3 within a range of pore diameters of 5 nm to 70 nm, which is obtained from the nitrogen adsorption isotherm by the DFT method. 3 [5] The carbon support according to any one of [1] to [4] may have a pore volume (cm) of pores having a diameter in the range of more than 0 nm and not more than 70 nm. 3 / g) of the pores in the range of less than 5 nm in diameter. 3 [6] In any of the carbon supports [1] to [5], the most frequent diameter, which is the pore diameter that gives the maximum value of the Log differential pore volume within the pore diameter range of more than 0 nm and not more than 70 nm in a Log differential pore volume distribution obtained from the nitrogen adsorption isotherm by a DFT method, may be less than 9.0 nm.

[0017] [7] Any of the carbon supports [1] to [6] has a specific surface area of ​​500 m2 or less obtained by the BET method from the nitrogen adsorption isotherm. 2[8] The carbon support of any one of [1] to [7] may have a specific surface area of ​​2000 m2 or more obtained by the BET method from the nitrogen adsorption isotherm. 2 / g or less.

[0018] [9] Any of the carbon supports [1] to [8] has a Raman shift of 1580 cm in a Raman spectrum obtained by Raman spectroscopy. -1 The half-width at half maximum of the G band, which has a peak top near -1

[10] The carbon support of any one of [1] to [9] may have a carbon structure exhibiting the following:

[10] In a Raman spectrum obtained by Raman spectroscopy, the carbon support may have a Raman shift of 2700 cm -1 The half-width at half maximum of the 2D band with a peak top near 80 cm -1 It may have the carbon structure shown below:

[0019]

[11] The carbon support according to any one of [1] to

[10] has a Raman shift of 1580 cm in a Raman spectrum obtained by Raman spectroscopy. -1 Raman shift of the G band intensity with a peak top near 1340 cm -1

[12] The carbon support of any one of [1] to

[11] may have a carbon structure in which the D / G ratio, which is the ratio of the intensities of the D bands having a peak top around 1580 cm, is 1.3 or more. -1 Raman shift of the G band intensity with a peak top near 2700 cm -1

[13] The carbon support according to any one of [1] to

[12] may have a nitrogen content of 0.2 wt % or more as determined by elemental analysis.

[0020]

[14] A metal-supported catalyst according to one embodiment of the present invention for solving the above problems includes the carbon support according to any one of [1] to

[13] above, and catalytic metal particles supported on the carbon support. According to the present invention, a metal-supported catalyst whose performance is effectively maintained is provided.

[0021]

[15] An electrode according to one embodiment of the present invention for solving the above problems includes the metal-supported catalyst according to

[14] . According to the present invention, an electrode whose performance is effectively maintained is provided.

[0022]

[16] A battery according to one embodiment of the present invention for solving the above problems includes the electrode according to

[15] . According to the present invention, a battery whose performance is effectively maintained is provided. [Effects of the Invention]

[0023] According to the present invention, there are provided a carbon support that achieves effective maintenance of the performance of a metal-supported catalyst, as well as a metal-supported catalyst, an electrode, and a battery in which the performance is effectively maintained. [Brief explanation of the drawings]

[0024] [Figure 1A] FIG. 2 is an explanatory diagram showing the Log differential pore volume distribution of carbon supports in Examples 1 to 3 of the examples according to the present embodiment. [Figure 1B] FIG. 2 is an explanatory diagram showing the Log differential pore volume distribution of carbon supports of Examples C1 to C4 in Examples according to the present embodiment. [Figure 1C] FIG. 2 is an explanatory diagram showing the Log differential pore volume distribution of carbon supports of Examples C5 to C7 in Examples according to the present embodiment. [Figure 2A] FIG. 1 is an explanatory diagram showing an example of the results of evaluating the characteristics of a carbon support and the performance of a metal-supported catalyst in an example according to the present embodiment. [Figure 2B] FIG. 10 is an explanatory diagram showing another example of the results of evaluating the characteristics of the carbon support in an example according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0025] An embodiment of the present invention will be described below, but the present invention is not limited to the example shown in this embodiment.

[0026] The carbon support according to this embodiment (hereinafter referred to as "the support") is a carbon support used to support catalytic metal particles. The support has a volume of pores with a pore diameter in the range of more than 0 nm and not more than 70 nm (hereinafter referred to as "pore volume (0-70 nm)") of 0.70 cm3, as obtained by the DFT method from a nitrogen adsorption isotherm at a temperature of 77 K. 3 / g or less.

[0027] The pore volume (#0-70 nm) of this support is, for example, 0.68 cm 3 / g or less, and 3 / g or less is more preferable, and 0.63 cm 3 / g or less is more preferable, and 0.60 cm 3 / g or less is more preferable, and 0.58 cm 3 It is particularly preferable that the saturation coefficient is 1 / g or less.

[0028] The pore volume (#0-70 nm) of the present support, which is equal to or less than the upper limit, contributes to the catalytic activity of the metal-supported catalyst containing the present support. That is, a metal-supported catalyst containing a carbon support with a large pore volume (#0-70 nm) has a low bulk density. Therefore, if the amount of electrolyte material mixed with the metal-supported catalyst is reduced, the metal-supported catalyst containing the carbon support is not sufficiently covered with the electrolyte material. As a result, the formation of ion conduction paths is insufficient, and the catalytic activity of the metal-supported catalyst is reduced.

[0029] In contrast, since the pore volume (#0-70 nm) of the present carrier is not too large, even if the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is sufficiently coated with the electrolyte material, and the catalytic activity of the metal-supported catalyst is effectively maintained.

[0030] The lower limit of the pore volume (#0-70 nm) of the carrier is not particularly limited as long as the effects of the present invention can be obtained. However, the pore volume #0-70 nm is, for example, 0.10 cm 3 / g or more, and 3 / g or more, and 3 / g or more, and 3 / g or more, and 3 / g or more, and 3 The pore volume (#0-70 nm) of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0031] The pore volume (#0-70 nm) of the present support equal to or greater than the lower limit contributes to further improving the catalytic activity of metal-supported catalysts containing the present support. That is, if the pore volume (#0-70 nm) of the carbon support is too small, the number of support sites for catalytic metal particles on the carbon support will be too small, limiting the amount of catalytic metal particles supported on the carbon support and making it impossible to enhance the catalytic activity of metal-supported catalysts containing the carbon support.

[0032] In contrast, when the present carrier has a pore volume (#0-70 nm) equal to or greater than the lower limit, a sufficient amount of catalytic metal particles is supported on the carrier, further improving the catalytic activity of the metal-supported catalyst containing the carrier.

[0033] The volume of pores with diameters of less than 5 nm (hereinafter referred to as "pore volume (<5 nm)") obtained from the nitrogen adsorption isotherm at a temperature of 77 K by the DFT method is 0.31 cm 3 / g or more.

[0034] The pore volume (<5 nm) of the support is, for example, 0.32 cm 3 / g or more, and 3 / g or more is more preferable, and 0.34 cm 3 / g or more is more preferable, and 0.35 cm 3 / g or more is more preferable, and 3 / g or more is more preferable, and 3 / g or more is more preferable, and 0.38 cm 3 It is particularly preferable that the saturation coefficient is 1 / g or more.

[0035] The pore volume (<5 nm) of the support above the lower limit contributes to the catalytic activity of the metal-supported catalyst containing the support. That is, when a carbon support contains many large-diameter pores, if the amount of electrolyte material mixed with the metal-supported catalyst containing the carbon support is reduced, the coating of the electrolyte material at the pore openings is likely to be interrupted, resulting in the ion conduction path being interrupted and the catalytic activity of the metal-supported catalyst being reduced.

[0036] In contrast, the present carrier, whose pore volume (#<5 nm) is equal to or greater than the above lower limit, contains many pores with relatively small diameters. Therefore, even if the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is maintained covered with the electrolyte material, and the catalytic activity of the metal-supported catalyst is effectively maintained.

[0037] The upper limit of the pore volume (#<5 nm) of the carrier is not particularly limited as long as the effects of the present invention can be obtained. However, the pore volume (#<5 nm) is, for example, 0.70 cm 3 / g or less, and 3 / g or less, and 3 / g or less, and 3 The pore volume (#<5 nm) of the present support may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0038] The pore volume of the present support below the upper limit (<5 nm) contributes to further improving the catalytic activity of metal-supported catalysts containing the present support. That is, a metal-supported catalyst containing a carbon support with a pore volume that is too large will have a low bulk density. Therefore, if the amount of electrolyte material mixed with the metal-supported catalyst is reduced, the metal-supported catalyst containing the carbon support will not be sufficiently coated with the electrolyte material. As a result, the formation of ion conduction paths will be insufficient, and the catalytic activity of the metal-supported catalyst may decrease.

[0039] In contrast, since the pore volume (<5 nm) of the present carrier is not too large, even when the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is sufficiently coated with the electrolyte material, and the catalytic activity of the metal-supported catalyst is more effectively maintained.

[0040] As described above, the present support has a relatively small pore volume (#0-70 nm) and a relatively large pore volume (#<5 nm), so even if the amount of electrolyte material mixed with the metal-supported catalyst containing the present support is reduced, the performance of the metal-supported catalyst is effectively maintained.

[0041] The carrier has a pore volume of pores with diameters in the range of 5 nm to 70 nm (hereinafter referred to as "pore volume (#5-70 nm)") of 1.00 cm, as determined by the DFT method from a nitrogen adsorption isotherm at a temperature of 77 K. 3 / g or less.

[0042] The pore volume (#5-70 nm) of this carrier is, for example, 0.95 cm 3 / g or less, and 3 / g or less is more preferable, and 0.85 cm 3 / g or less is more preferable, and 0.80 cm 3 / g or less is more preferable, and 0.75 cm 3 / g or less is more preferable, and 0.70 cm 3 / g or less is more preferable, and 0.65 cm 3 / g or less is more preferable, and 0.60 cm 3 / g or less is more preferable, and 0.55 cm 3 / g or less is more preferable, and 0.50 cm 3 / g or less is more preferable, and 0.45 cm 3 / g or less is more preferable, and 0.40 cm 3 / g or less is more preferable, and 0.35 cm 3 / g or less is more preferable, and 0.30 cm 3 / g or less is more preferable, and 0.25 cm 3 / g or less is more preferable, and 0.20 cm 3 / g or less is more preferable, and 0.15 cm 3 / g or less is more preferable, and 0.10 cm 3 / g or less is more preferable, and 0.05 cm 3 It is particularly preferable that the saturation coefficient is 1 / g or less.

[0043] The pore volume (#5-70 nm) of this support, which is equal to or less than the upper limit, contributes to further improving the catalytic activity of metal-supported catalysts containing this support. That is, a metal-supported catalyst containing a carbon support with a pore volume (#5-70 nm) that is too large has a low bulk density. Therefore, if the amount of electrolyte material mixed with the metal-supported catalyst is reduced, the metal-supported catalyst containing the carbon support is not sufficiently covered with the electrolyte material. As a result, the formation of ion conduction paths is insufficient, and the catalytic activity of the metal-supported catalyst may be reduced.

[0044] In contrast, in the present carrier, whose pore volume (#5-70 nm) is equal to or less than the upper limit, the volume of pores with relatively large diameters is relatively small. Therefore, even when the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is likely to be covered with the electrolyte material, and the catalytic activity of the metal-supported catalyst is more effectively maintained.

[0045] The lower limit of the pore volume (#5-70 nm) of the carrier is not particularly limited as long as the effects of the present invention can be obtained. However, the pore volume (#5-70 nm) is, for example, 0.005 cm 3 / g or more, and 3 / g or more, and 3 The pore volume (#5-70 nm) of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0046] The volume of pores with diameters in the range of 5 nm to 70 nm (pore volume (#5-70 nm)) (cm) obtained from the nitrogen adsorption isotherm at 77 K by the DFT method. 3 / g) vs. the volume of pores in the range of pore diameters less than 5 nm (pore volume (#<5 nm)) (cm 3 / g) (hereinafter referred to as "pore volume ratio (#5 / (5-70 nm))") may be 9.0 or more.

[0047] The pore volume ratio (#5 / (5-70 nm)) of the carrier is, for example, preferably 9.2 or more, more preferably 9.5 or more, even more preferably 9.7 or more, even more preferably 10.0 or more, even more preferably 10.5 or more, even more preferably 11.0 or more, even more preferably 11.5 or more, even more preferably 12.0 or more, and particularly preferably 12.5 or more.

[0048] The pore volume ratio (#5 / (5-70 nm)) of this support equal to or greater than the lower limit contributes to further improving the catalytic activity of metal-supported catalysts containing this support. That is, when a carbon support contains many pores with large diameters, if the amount of electrolyte material mixed with the metal-supported catalyst containing the carbon support is reduced, the coating of the electrolyte material at the openings of the pores is likely to be interrupted, resulting in the ion conduction path being interrupted and the catalytic activity of the metal-supported catalyst being reduced.

[0049] In contrast, the present carrier, whose pore volume ratio (#5 / (5-70 nm)) is equal to or greater than the above lower limit, contains many pores with relatively small diameters. Therefore, even if the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is more likely to be covered with the electrolyte material, and the catalytic activity of the metal-supported catalyst is more effectively maintained.

[0050] The upper limit of the pore volume ratio (#5 / (5-70 nm)) of the present carrier is not particularly limited as long as the effects of the present invention are obtained, but the pore volume ratio (#5 / (5-70 nm)) may be, for example, 50.0 or less, 45.0 or less, 40.0 or less, 35.0 or less, 30.0 or less, 28.0 or less, 25.0 or less, 24.0 or less, 23.0 or less, 22.0 or less, or 21.5 or less. The pore volume ratio (#5 / (5-70 nm)) of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0051] The volume of pores with diameters in the range of more than 0 nm and not more than 70 nm (pore volume (#0-70 nm)) (cm) obtained from the nitrogen adsorption isotherm at a temperature of 77 K by the DFT method. 3 / g) vs. the volume of pores in the range of pore diameters less than 5 nm (pore volume (#<5 nm)) (cm 3 / g) (hereinafter referred to as "pore volume ratio (#5 / (0-70 nm))") may be 0.50 or more.

[0052] The pore volume ratio (#5 / (0-70 nm)) of the carrier is, for example, preferably 0.55 or more, more preferably 0.60 or more, even more preferably 0.65 or more, even more preferably 0.70 or more, even more preferably 0.75 or more, even more preferably 0.80 or more, even more preferably 0.82 or more, even more preferably 0.84 or more, even more preferably 0.86 or more, even more preferably 0.88 or more, and particularly preferably 0.90 or more.

[0053] The pore volume ratio (#5 / (0-70 nm)) of the present support equal to or greater than the lower limit contributes to further improving the catalytic activity of metal-supported catalysts containing the present support. That is, when a carbon support contains many pores with large diameters, if the amount of electrolyte material mixed with the metal-supported catalyst containing the carbon support is reduced, the coating of the electrolyte material at the openings of the pores is likely to be interrupted, resulting in the ion conduction path being interrupted and the catalytic activity of the metal-supported catalyst being reduced.

[0054] In contrast, the present carrier, whose pore volume ratio (#5 / (0-70 nm)) is equal to or greater than the above lower limit, contains many pores with relatively small diameters. Therefore, even if the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is more likely to be covered with the electrolyte material, and the catalytic activity of the metal-supported catalyst is more effectively maintained.

[0055] The upper limit of the pore volume ratio (#5 / (0-70 nm)) of the present carrier is not particularly limited as long as the effects of the present invention are obtained, but the pore volume ratio (#5 / (5-70 nm)) may be, for example, 1.00 or less, or may be less than 1.00. The pore volume ratio (#5 / (0-70 nm)) of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0056] The volume of pores with diameters of less than 2 nm (hereinafter referred to as "pore volume (<2 nm)") obtained from the nitrogen adsorption isotherm at a temperature of 77 K by the DFT method is 0.10 cm 3 / g or more.

[0057] The pore volume (<2 nm) of the support is, for example, 0.11 cm 3 / g or more, and 3 / g or more is more preferable, and 0.13 cm 3 / g or more is more preferable, and 0.14 cm 3 / g or more is more preferable, and 0.15 cm 3 / g or more is more preferable, and 3 / g or more is more preferable, and 0.17 cm 3 / g or more is more preferable, and 0.18 cm 3 / g or more is more preferable, and 0.19 cm 3 It is particularly preferable that the saturation coefficient is 1 / g or more.

[0058] The pore volume (<2 nm) of the present support equal to or greater than the lower limit contributes to further improving the catalytic activity of metal-supported catalysts containing the present support. That is, when a carbon support contains many large-diameter pores, if the amount of electrolyte material mixed with the metal-supported catalyst containing the carbon support is reduced, the coating of the electrolyte material at the pore openings is likely to be interrupted, resulting in the ion conduction path being interrupted and the catalytic activity of the metal-supported catalyst being reduced.

[0059] In contrast, the present carrier, whose pore volume (#<2 nm) is equal to or greater than the above lower limit, contains many pores with relatively small diameters. Therefore, even if the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is likely to be covered with the electrolyte material, and the catalytic activity of the metal-supported catalyst is effectively maintained.

[0060] The upper limit of the pore volume (#<2 nm) of the carrier is not particularly limited as long as the effects of the present invention can be obtained. However, the pore volume (#<2 nm) is, for example, 0.70 cm 3 / g or less, and 3 / g or less, and 3 / g or less, and 3 / g or less, and 3 / g or less, and 3 / g or less, and 3 / g or less, and 3 / g or less, and 3 The pore volume (#<2 nm) of the present support may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0061] The pore volume of the present support below the upper limit (<2 nm) contributes to further improving the catalytic activity of metal-supported catalysts containing the present support. That is, a metal-supported catalyst containing a carbon support with a pore volume that is too large will have a low bulk density. Therefore, if the amount of electrolyte material mixed with the metal-supported catalyst is reduced, the metal-supported catalyst containing the carbon support will not be sufficiently covered with the electrolyte material. As a result, the formation of ion conduction paths will be insufficient, and the catalytic activity of the metal-supported catalyst may decrease.

[0062] In contrast, since the pore volume (#<2 nm) of the present carrier is not too large, even when the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is easily covered with the electrolyte material, and the catalytic activity of the metal-supported catalyst is more effectively maintained.

[0063] The volume of pores in the range of pore diameters of 2 nm to 10 nm (hereinafter referred to as "pore volume (#2-10 nm)") obtained by the DFT method from the nitrogen adsorption isotherm at a temperature of 77 K is 0.80 cm 3 / g or less.

[0064] The pore volume (#2-10 nm) of this support is, for example, 0.75 cm 3 / g or less, and 3 / g or less is more preferable, and 0.65 cm 3 / g or less is more preferable, and 0.60 cm 3 / g or less is more preferable, and 0.55 cm 3 / g or less is more preferable, and 0.50 cm 3 / g or less is more preferable, and 0.45 cm 3 / g or less is more preferable, and 0.40 cm 3 / g or less is more preferable, and 0.37 cm 3 / g or less is more preferable, and 0.35 cm 3 / g or less is more preferable, and 0.30 cm 3 / g or less is more preferable, and 0.28 cm 3 It is particularly preferable that the saturation coefficient is 1 / g or less.

[0065] The pore volume (#2-10 nm) of this support that is equal to or less than the upper limit contributes to further improving the catalytic activity of metal-supported catalysts that include this support. That is, a metal-supported catalyst that includes a carbon support with a pore volume (#2-10 nm) that is too large has a low bulk density. Therefore, if the amount of electrolyte material mixed with the metal-supported catalyst is reduced, the metal-supported catalyst that includes the carbon support is not sufficiently covered with the electrolyte material. As a result, the formation of ion conduction paths is insufficient, and the catalytic activity of the metal-supported catalyst may be reduced.

[0066] In contrast, when the pore volume (#2-10 nm) of the present carrier is not too large, even if the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is likely to be sufficiently coated with the electrolyte material, and the catalytic activity of the metal-supported catalyst is more effectively maintained.

[0067] The lower limit of the pore volume (#2-10 nm) of the carrier is not particularly limited as long as the effects of the present invention can be obtained. However, the pore volume (#2-10 nm) is, for example, 0.05 cm 3 / g or more, and 3 / g or more, and 3 / g or more, and 3 The pore volume (#2-10 nm) of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0068] The pore volume (#2-10 nm) of the present support equal to or greater than the lower limit mentioned above contributes to further improving the catalytic activity of metal-supported catalysts containing the present support. That is, if the pore volume (#2-10 nm) of the carbon support is too small, the number of support sites for catalytic metal particles on the carbon support will be too small, limiting the amount of catalytic metal particles supported on the carbon support, and making it impossible to enhance the catalytic activity of metal-supported catalysts containing the carbon support.

[0069] In contrast, when the present carrier has a pore volume (#2-10 nm) equal to or greater than the lower limit, the amount of catalytic metal particles supported on the carrier is easily ensured, and the catalytic activity of the metal-supported catalyst containing the carrier is further improved.

[0070] The volume of pores with diameters in the range of 10 nm to 70 nm (hereinafter referred to as "pore volume (10-70 nm)") obtained by the DFT method from the nitrogen adsorption isotherm at a temperature of 77 K is 0.50 cm 3 / g or less.

[0071] The pore volume (#10-70 nm) of this carrier is, for example, 0.45 cm 3 / g or less, and 3 / g or less is more preferable, and 0.35 cm 3 / g or less is more preferable, and 0.30 cm 3 / g or less is more preferable, and 0.25 cm 3 / g or less is more preferable, and 0.20 cm 3 / g or less is more preferable, and 0.15 cm 3 / g or less is more preferable, and 0.10 cm 3 / g or less is more preferable, and 0.08 cm 3 / g or less is more preferable, and 0.05 cm 3 / g or less is more preferable, and 0.03 cm 3 / g or less is more preferable, and 0.02 cm 3 It is particularly preferable that the saturation coefficient is 1 / g or less.

[0072] The pore volume (#10-70 nm) of this support that is equal to or less than the upper limit contributes to further improving the catalytic activity of metal-supported catalysts that include this support. That is, a metal-supported catalyst that includes a carbon support with a pore volume (#10-70 nm) that is too large has a low bulk density. Therefore, if the amount of electrolyte material mixed with the metal-supported catalyst is reduced, the metal-supported catalyst that includes the carbon support is not sufficiently covered with the electrolyte material. As a result, the formation of ion conduction paths is insufficient, and the catalytic activity of the metal-supported catalyst may be reduced.

[0073] In contrast, in the present carrier, whose pore volume (#10-70 nm) is equal to or less than the upper limit, the volume of pores with relatively large diameters is relatively small. Therefore, even when the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is likely to be covered with the electrolyte material, and the catalytic activity of the metal-supported catalyst is more effectively maintained.

[0074] The lower limit of the pore volume (#10-70 nm) of the carrier is not particularly limited as long as the effects of the present invention can be obtained. However, the pore volume (#10-70 nm) is, for example, 0.001 cm 3 / g or more, and 3 / g or more, and 3The pore volume (#10-70 nm) of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0075] The support may have a most frequent diameter, which is the pore diameter that gives the maximum value of the Log differential pore volume within a pore diameter range of more than 0 nm and not more than 70 nm in a Log differential pore volume distribution obtained by a DFT method from a nitrogen adsorption isotherm at a temperature of 77 K, of less than 9.0 nm.

[0076] That is, the most frequent diameter of the pores of the present support is defined as the pore diameter that gives the largest Log differential pore volume within the pore diameter range of more than 0 nm and not more than 70 nm in the Log differential pore volume distribution of the present support obtained by DFT from a nitrogen adsorption isotherm at a temperature of 77 K. When the present support has a most frequent diameter of less than 9.0 nm, the present support has a porous carbon structure in which the peak top of the peak that gives the largest Log differential pore volume within the pore diameter range of more than 0 nm and not more than 70 nm in the Log differential pore volume distribution obtained by DFT appears at a position within the pore diameter range of less than 9.0 nm.

[0077] The most frequent diameter of the pores of the present carrier is, for example, preferably 8.5 nm or less, more preferably 8.0 nm or less, even more preferably 7.5 nm or less, even more preferably 7.0 nm or less, even more preferably 6.5 nm or less, even more preferably 6.0 nm or less, even more preferably 5.5 nm or less, even more preferably 5.0 nm or less, even more preferably 4.5 nm or less, even more preferably 4.0 nm or less, even more preferably 3.5 nm or less, even more preferably 3.0 nm or less, and particularly preferably 2.9 nm or less.

[0078] A modal diameter of the present support equal to or less than the above upper limit contributes to further improving the catalytic activity of a metal-supported catalyst containing the present support. That is, a carbon support with a too large modal diameter contains many pores with relatively large diameters. Therefore, when the amount of electrolyte material mixed with a metal-supported catalyst containing the carbon support is reduced, the coating with the electrolyte material at the openings of the pores is interrupted, resulting in the interruption of the ion conduction path and the resulting reduction in the catalytic activity of the metal-supported catalyst.

[0079] In contrast, when the most frequent diameter of the pores of the present support is equal to or less than the above upper limit, even if the amount of electrolyte material mixed with the metal-supported catalyst including the present support is reduced, the coating of the metal-supported catalyst including the present support with the electrolyte material is likely to be maintained, and the catalytic activity of the metal-supported catalyst is more effectively maintained.

[0080] The lower limit of the most frequent diameter of the pores of the present support is not particularly limited as long as the effects of the present invention are obtained, but the most frequent diameter may be, for example, 1.0 nm or more, 1.5 nm or more, 2.0 nm or more, 2.2 nm or more, or 2.4 nm or more. The most frequent diameter of the pores of the present support may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0081] The specific surface area of ​​this carrier, obtained by the BET method from the nitrogen adsorption isotherm at a temperature of 77 K (hereinafter referred to as "BET specific surface area"), is 500 m 2 The BET specific surface area of ​​the carrier may be, for example, 550 m 2 / g or more is preferable, and 600m 2 / g or more is more preferable, and 650m 2 / g or more is more preferable, and 700m 2 / g or more is more preferable, and 750m 2 / g or more is more preferable, and 2 It is particularly preferable that the saturation coefficient is 1 / g or more.

[0082] A BET specific surface area of ​​the present support equal to or greater than the above lower limit contributes to further improving the catalytic activity of a metal-supported catalyst containing the present support. That is, if the BET specific surface area of ​​the carbon support is too small, the number of support sites for catalytic metal particles on the carbon support will be too small, limiting the amount of catalytic metal particles supported on the carbon support, and making it impossible to enhance the catalytic activity of a metal-supported catalyst containing the carbon support.

[0083] In contrast, when the present carrier has a BET specific surface area equal to or greater than the lower limit, the amount of catalytic metal particles supported on the present carrier is easily ensured, and the catalytic activity of the metal-supported catalyst containing the present carrier is further improved.

[0084] This carrier has a BET specific surface area of ​​2000m 2 In this case, the BET specific surface area of ​​the carrier may be, for example, 1900 m 2 / g or less, and 1800m 2 / g or less is more preferable, and 1700m 2 / g or less is more preferable, and 2 / g or less is more preferable, and 1500m 2 / g or less is more preferable, and 1450m 2 / g or less, and 2 / g or less is more preferable, and 1350m 2 / g or less is more preferable, and 2 / g or less is more preferable, and 1250m 2 / g or less is more preferable, and 2 / g or less is particularly preferred. The BET specific surface area of ​​the present support may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0085] A BET specific surface area of ​​the present support that is equal to or less than the upper limit contributes to further improving the catalytic activity of a metal-supported catalyst containing the present support. That is, if the BET specific surface area of ​​the carbon support is too large, and the amount of electrolyte material mixed with the metal-supported catalyst containing the carbon support is reduced, the metal-supported catalyst containing the carbon support will not be sufficiently covered with the electrolyte material, resulting in insufficient formation of ion conduction paths and a decrease in the catalytic activity of the metal-supported catalyst.

[0086] In contrast, when the present carrier has a BET specific surface area equal to or less than the above upper limit, even if the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is likely to be sufficiently coated with the electrolyte material, and the catalytic activity of the metal-supported catalyst is more effectively maintained.

[0087] This carrier exhibits a Raman shift of 1340 cm in the Raman spectrum obtained by Raman spectroscopy. -1 Around (specifically, for example, 1320 cm -1 Above, 1360cm -1 The half-width at half maximum of the D band (hereinafter referred to as "Raman D half-width at half maximum") having a peak top within the range of 60 cm -1 It may have the carbon structure shown below:

[0088] The Raman D half width at half maximum of this support is, for example, 55 cm -1 Preferably less than 50cm -1 Preferably less than 45cm -1 More preferably, it is 40 cm or less. -1 It is particularly preferred that:

[0089] The Raman D half-width at half maximum of the present support, which is equal to or less than the upper limit, contributes to improving the durability of metal-supported catalysts containing the support. Specifically, according to a reference (A. Sadezky et al., Carbon 43 (2005) 1731-1742), in the Raman spectrum of a carbon material, the D band is a component derived from carbon atoms adjacent to disordered lattices such as edges and defects in graphene layers. The Raman D half-width at half maximum indicates the crystallinity of the carbon around the edges and defects. In other words, the higher the crystallinity of the carbon around the edges and defects in the carbon structure, the smaller the Raman D half-width at half maximum of the carbon structure. Furthermore, the higher the crystallinity of the carbon, the more stable the carbon structure. Therefore, when the carbon structure of the present support exhibits a Raman D half-width at half maximum of the above upper limit or less, the durability of metal-supported catalysts containing the present support is effectively improved.

[0090] The lower limit of the Raman D half width at half maximum of the carrier is not particularly limited as long as the effects of the present invention can be obtained. For example, -1 It may be more than 15cm -1 It may be more than 20cm -1 May be more than 25cm -1 The Raman D half width at half maximum of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0091] A Raman D half width at half maximum of the present support equal to or greater than the above lower limit contributes to further improving the catalytic activity of metal-supported catalysts containing the present support. That is, if the Raman D half width at half maximum of the carbon support is too small, the carbon structure of the carbon support may have too high a crystallinity of carbon around edges and defects, making it insufficient for supporting catalytic metal particles.

[0092] In contrast, when the present support has a carbon structure that exhibits an appropriate Raman D half width at half maximum, the present support has excellent suitability for supporting catalytic metal particles, and the catalytic activity of a metal-supported catalyst including the present support is further improved.

[0093] This carrier exhibits a Raman shift of 1580 cm in the Raman spectrum obtained by Raman spectroscopy. -1 around (specifically, for example, 1550 cm -1 Over, 1610cm -1 The half-width at half maximum of the G band (hereinafter referred to as "Raman G half-width at half maximum") having a peak top within the range of 60 cm -1 It may have the carbon structure shown below:

[0094] The Raman G half-width at half maximum of this support is, for example, 55 cm -1 Preferably less than 50cm -1 Preferably less than 45cm -1 More preferably, it is 40 cm or less. -1 More preferably, it is 37 cm or less. -1 More preferably, it is 35 cm or less. -1 It is particularly preferred that:

[0095] The Raman G half width at half maximum of the present support, which is equal to or less than the upper limit, contributes to improving the durability of metal-supported catalysts containing the present support. That is, in the Raman spectrum of a carbon material, the G band is a component derived from the carbon atoms that constitute graphene. The Raman G half width at half maximum indicates the degree of graphene development. That is, as the graphene contained in the carbon structure develops, the Raman G half width at half maximum of the carbon structure becomes smaller. Furthermore, as the graphene develops, the stability of the carbon structure increases. Therefore, when the carbon structure of the present support exhibits a Raman G half width at half maximum of the above upper limit or less, the durability of metal-supported catalysts containing the present support is effectively improved.

[0096] The lower limit of the Raman G half width at half maximum of the carrier is not particularly limited as long as the effects of the present invention can be obtained. For example, -1 It may be more than 15cm -1 It may be more than 20cm -1 May be more than 25cm -1The Raman G half width at half maximum of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0097] A Raman G half width at half maximum of the present support equal to or greater than the above lower limit contributes to further improving the catalytic activity of a metal-supported catalyst containing the present support. That is, if the Raman G half width at half maximum of the carbon support is too small, the carbon structure of the carbon support may be too graphene-developed, making it insufficient for supporting catalytic metal particles.

[0098] In contrast, when the present support has a carbon structure that exhibits a Raman G half width at half maximum of an appropriate size, the present support has excellent suitability for supporting catalytic metal particles, and the catalytic activity of a metal-supported catalyst including the present support is further improved.

[0099] This carrier exhibits a Raman shift of 2700 cm in the Raman spectrum obtained by Raman spectroscopy. -1 around (specifically, for example, 2650 cm -1 More than 2750cm -1 The half-width at half maximum of the 2D band having a peak top within the range of 80 cm or less (hereinafter referred to as "Raman 2D half-width at half maximum") is -1 It may have the carbon structure shown below:

[0100] The Raman 2D half width at half maximum of this support is, for example, 75 cm -1 Preferably less than 70cm -1 Preferably less than 65cm -1 More preferably, it is 60 cm or less. -1 More preferably, it is 59 cm or less. -1 More preferably, it is 58cm or less. -1 More preferably, it is 57 cm or less. -1 It is particularly preferred that:

[0101] The Raman 2D half-width at half maximum of the present support, which is equal to or less than the upper limit, contributes to improving the durability of metal-supported catalysts containing the present support. In other words, in the Raman spectrum of a carbon material, the 2D band is a component derived from the carbon atoms constituting the graphene layer. The Raman 2D half-width at half maximum indicates the uniformity of the graphene layer. That is, as the graphene layer contained in a carbon structure becomes more uniform, the Raman 2D half-width at half maximum of the carbon structure becomes smaller. Furthermore, as the graphene layer becomes more uniform, the stability of the carbon structure increases. Therefore, when the carbon structure of the present support exhibits a Raman 2D half-width at half maximum of the above upper limit or less, the durability of metal-supported catalysts containing the present support is effectively improved.

[0102] The lower limit of the Raman 2D half width at half maximum of the carrier is not particularly limited as long as the effects of the present invention can be obtained. For example, -1 It may be more than 15cm -1 It may be more than 20cm -1 May be more than 25cm -1 It may be more than 30cm -1 It may be more than 35cm -1 It may be more than 40cm -1 It may be more than 45cm -1 It may be more than 50cm -1 The Raman 2D half width at half maximum of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0103] A Raman 2D half width at half maximum of the present support equal to or greater than the above lower limit contributes to further improving the catalytic activity of a metal-supported catalyst containing the present support. That is, if the Raman 2D half width at half maximum of the carbon support is too small, the carbon structure of the carbon support may be insufficiently suitable for supporting catalytic metal particles because the graphene layers have too high uniformity.

[0104] In contrast, when the present support has a carbon structure that exhibits a Raman 2D half width at half maximum of an appropriate size, the present support has excellent suitability for supporting catalytic metal particles, and the catalytic activity of a metal-supported catalyst including the present support is further improved.

[0105] The carrier may have a carbon structure in which the D / G ratio, which is the ratio of the intensity of the D band to the intensity of the G band in a Raman spectrum obtained by Raman spectroscopy (hereinafter referred to as "Raman D / G ratio"), is 1.3 or more.

[0106] The Raman D / G of the present support is, for example, preferably 1.4 or more, more preferably 1.5 or more, even more preferably 1.6 or more, still more preferably 1.7 or more, and particularly preferably 1.8 or more.

[0107] A Raman D / G ratio of the present support equal to or greater than the above-mentioned lower limit contributes to further improving the catalytic activity of metal-supported catalysts containing the present support. Specifically, the Raman D / G ratio of a carbon material indicates the amount of edges and defects contained in the graphene layers in the carbon structure. That is, the more edges and defects in the graphene layers, the higher the Raman D / G ratio of the carbon structure. In this regard, the edges and defects function as support sites for catalytic metal particles. Therefore, the more edges and defects in the graphene layers, the better the carbon structure's suitability for supporting catalytic metal particles. Therefore, when the present support has a Raman D / G ratio equal to or greater than the above-mentioned lower limit, the present support has excellent suitability for supporting catalytic metal particles, thereby further improving the catalytic activity of metal-supported catalysts containing the present support.

[0108] The upper limit of the Raman D / G ratio of the present carrier is not particularly limited as long as the effects of the present invention are obtained, but may be, for example, 4.0 or less, 3.5 or less, 3.0 or less, 2.8 or less, 2.6 or less, 2.4 or less, 2.2 or less, or 2.1 or less. The Raman D / G ratio of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0109] A Raman D / G ratio of the present support that is equal to or less than the upper limit contributes to improving the durability of metal-supported catalysts that include the present support. That is, a carbon structure that exhibits a Raman D / G ratio that is too large may have too many edges and defects, resulting in reduced durability.

[0110] In contrast, a carbon structure exhibiting a moderate Raman D / G ratio has a moderate amount of edges and defects, thereby maintaining durability. Therefore, when the carbon structure of the present support exhibits a Raman D / G ratio below the upper limit, the durability of a metal-supported catalyst containing the present support is effectively improved.

[0111] The carrier may have a carbon structure in which the 2D / G ratio (hereinafter referred to as "Raman 2D / G ratio"), which is the ratio of the intensity of the 2D band to the intensity of the G band, is 0.2 or more in a Raman spectrum obtained by Raman spectroscopy. In this case, it is particularly preferable that the Raman 2D / G ratio of the carrier is, for example, 0.3 or more.

[0112] Here, the Raman 2D / G ratio of a carbon material indicates the number of layers constituting the graphene laminate contained in the carbon structure of the carbon material. That is, when the intensity of the 2D band is greater than the intensity of the G band (Raman 2D / G ratio > 1), the graphene is a single layer. When the intensity of the 2D band is the same as the intensity of the G band (Raman 2D / G ratio = 1), the number of layers in the graphene laminate is approximately two. When the intensity of the 2D band is smaller than the intensity of the G band (Raman 2D / G ratio < 1), the number of layers in the graphene laminate is three or more. The specific number of layers can be determined from the ratio of the intensity of the 2D band (peak top height) to the intensity of the G band (peak top height).

[0113] A Raman 2D / G ratio of the support equal to or greater than the lower limit contributes to improving the durability of metal-supported catalysts containing the support. That is, a carbon structure that exhibits a too small Raman 2D / G ratio, i.e., a carbon structure with too many graphene layers, may have a high relative amount of edges and defects, which are the starting points for oxidative degradation, relative to the basal plane, which may reduce durability (especially corrosion resistance).

[0114] In contrast, when the present support has a carbon structure exhibiting an appropriate Raman 2D / G ratio, the carbon structure contains few-layer graphene in which the number of graphene stacks is controlled within an appropriate range (for example, about 2 to 3 layers), and the relative amount of edges and defects with respect to the exposed basal plane is controlled within an appropriate range, thereby effectively improving the durability (particularly corrosion resistance) of metal-supported catalysts that include the present support.

[0115] The upper limit of the Raman 2D / G ratio of the present carrier is not particularly limited as long as the effects of the present invention are obtained, but may be, for example, 1.5 or less, 1.2 or less, 1.0 or less, 0.8 or less, 0.6 or less, 0.5 or less, or 0.4 or less. The Raman 2D / G ratio of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0116] A Raman 2D / G ratio of the present support below the upper limit contributes to further improving the catalytic activity of metal-supported catalysts containing the present support. That is, in the carbon structure of the carbon support, edges and defects also function as support sites for catalytic metal particles. Therefore, a carbon structure that exhibits a Raman 2D / G ratio that is too large may have too few edges and defects relative to the basal plane, reducing its suitability for supporting catalytic metal particles.

[0117] In contrast, when the present support has a carbon structure that exhibits a Raman 2D / G ratio of an appropriate magnitude, the carbon structure contains an appropriate number of edges and defects, and the present support is highly suitable for supporting catalytic metal particles, thereby further improving the catalytic activity of metal-supported catalysts that include the present support.

[0118] The oxygen content of the carrier may be 0.5% by weight or more as determined by elemental analysis (specifically, pyrolysis). The oxygen content of the carrier is, for example, preferably 0.7% by weight or more, more preferably 1.0% by weight or more, even more preferably 1.5% by weight or more, even more preferably 2.0% by weight or more, even more preferably 2.2% by weight or more, even more preferably 2.4% by weight or more, even more preferably 2.6% by weight or more, even more preferably 2.8% by weight or more, and particularly preferably 3.0% by weight or more.

[0119] An oxygen content of the present support equal to or greater than the above-mentioned lower limit contributes to further improving the catalytic activity of a metal-supported catalyst containing the present support. That is, generally, as the Raman G half-width at half maximum, Raman D half-width at half maximum, and Raman 2D half-width at half maximum exhibited by the carbon structure of the carbon support decrease, or as the Raman 2D / G ratio exhibited by the carbon structure increases, the hydrophilicity of the carbon structure decreases. However, even when the carbon structure of the carbon support exhibits a small Raman G half-width at half maximum, Raman D half-width at half maximum, or Raman 2D half-width at half maximum, and / or a large Raman 2D / G ratio, increasing the oxygen content of the carbon support increases the polarity of the carbon structure and the hydrophilicity of the carbon structure. Furthermore, a carbon support having a highly hydrophilic carbon structure is excellently suited for appropriately retaining generated water, for example, when a metal-supported catalyst containing the carbon support is applied to a fuel cell. Therefore, when the present carrier has an oxygen content equal to or greater than the above lower limit, the catalytic activity of a metal-supported catalyst containing the present carrier is further improved.

[0120] The upper limit of the oxygen content of the carrier is not particularly limited as long as the effects of the present invention are obtained, but may be, for example, 20.0 wt% or less, 15.0 wt% or less, 10.0 wt% or less, 8.0 wt% or less, 7.0 wt% or less, 6.0 wt% or less, 5.0 wt% or less, 4.5 wt% or less, or 4.0 wt% or less. The oxygen content of the carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0121] An oxygen content of the present support equal to or less than the upper limit mentioned above contributes to improving the durability of a metal-supported catalyst containing the present support. That is, the carbon structure of a carbon support with too high an oxygen content may have too many oxidation initiation points, resulting in reduced durability (especially corrosion resistance).

[0122] In contrast, when the support has an oxygen content that is not too high, the number of oxidation initiation points in the carbon structure of the support is not too large, and the durability (especially corrosion resistance) of a metal-supported catalyst that includes the support is effectively improved.

[0123] The present support may have a nitrogen content of 0.2% by weight or more as determined by elemental analysis (specifically, pyrolysis). The nitrogen content of the present support is, for example, preferably 0.3% by weight or more, and particularly preferably 0.4% by weight or more.

[0124] A nitrogen content of the present support equal to or greater than the above-mentioned lower limit contributes to further improving the catalytic activity of a metal-supported catalyst containing the present support. That is, an increase in the nitrogen content of the carbon support increases the polarity of the carbon structure contained in the carbon support, and the hydrophilicity of the carbon structure increases. Furthermore, a carbon support having a highly hydrophilic carbon structure is excellent in suitability for appropriately retaining generated water, for example, when a metal-supported catalyst containing the carbon support is applied to a fuel cell. Therefore, when the present support has a nitrogen content equal to or greater than the above-mentioned lower limit, the catalytic activity of a metal-supported catalyst containing the present support is further improved.

[0125] The upper limit of the nitrogen content of the present carrier is not particularly limited as long as the effects of the present invention are obtained, but may be, for example, 20.0 wt % or less, 15.0 wt % or less, 10.0 wt % or less, 5.0 wt % or less, 3.0 wt % or less, 2.0 wt % or less, or 1.0 wt % or less. The nitrogen content of the present carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0126] In the nitrogen adsorption isotherm at a temperature of 77 K, the difference (hereinafter referred to as "hysteresis (#0.5P / P0")) obtained by subtracting the nitrogen adsorption amount when the relative pressure P / P0 is 0.5, which is the ratio of the adsorption equilibrium pressure P to the saturated vapor pressure P0, from the nitrogen desorption amount when the relative pressure P / P0 is 0.5, is 30 cm 3 / g or less.

[0127] The hysteresis (#0.5P / P0) of this carrier is, for example, 25 cm 3 / g or less, and 3 / g or less is more preferable, and 15cm 3 The lower limit of the hysteresis (#0.5P / P0) of the carrier is not particularly limited as long as the effects of the present invention can be obtained. 3 The hysteresis (#0.5P / P0) of the carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0128] In the nitrogen adsorption isotherm at a temperature of 77 K, the difference (hereinafter referred to as "hysteresis (#0.8P / P0")) obtained by subtracting the nitrogen adsorption amount at a relative pressure P / P of 0.8, which is the ratio of the adsorption equilibrium pressure P to the saturated vapor pressure P, from the nitrogen desorption amount at the relative pressure P / P of 0.8, is 30 cm. 3 / g or less.

[0129] The hysteresis (#0.8P / P0) of this carrier is, for example, 25 cm 3 / g or less, and 3 / g or less is more preferable, and 15cm 3 The lower limit of the hysteresis (#0.8P / P0) of the carrier is not particularly limited as long as the effects of the present invention can be obtained. 3 The hysteresis (#0.8P / P0) of the carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0130] Here, as the interconnectivity of the pores contained in the carbon support increases, the hysteresis of the nitrogen adsorption isotherm of the carbon support decreases, resulting in smaller hysteresis (#0.5P / P0) and hysteresis (#0.8P / P0) of the carbon support. Therefore, when the support has a porous carbon structure (i.e., a highly interconnected porous carbon structure) that exhibits a hysteresis (#0.5P / P0) and / or a hysteresis (#0.8P / P0) that is equal to or less than the upper limit, excellent performance is achieved in fuel cells using a metal-supported catalyst containing the support as an electrode catalyst because water generated in the pores of the metal-supported catalyst is effectively discharged. Note that the hysteresis (#0.5P / P0) indicates the interconnectivity of pores with relatively small diameters, and the hysteresis (#0.8P / P0) indicates the interconnectivity of pores with relatively large diameters.

[0131] The carrier has a true density of 1.5 g / cm3 as determined by the constant volume expansion method. 3 The true density of the carrier may be, for example, 1.6 g / cm or more. 3 It is preferable that the concentration is 1.7 g / cm or more. 3 More preferably, it is 1.8 g / cm or more. 3 More preferably, it is 1.9 g / cm or more. 3 More preferably, it is 2.0 g / cm or more. 3 More preferably, it is 2.1 g / cm or more. 3 More preferably, it is equal to or greater than this.

[0132] A true density of the present support equal to or greater than the above lower limit contributes to further improving the catalytic activity of metal-supported catalysts containing the present support. That is, the true density of a porous carbon material measured by constant volume expansion method is smaller than that of a solid carbon material when the carbon material has blocked pores. Furthermore, for example, by subjecting a porous carbon material to graphitization, some of the pores contained in the carbon material are blocked, increasing the volume of the blocked pores. As a result, the measured true density of the carbon material after graphitization is smaller than that before graphitization. Thus, the true density of a carbon material reflects the volume of the blocked pores contained in the carbon material.

[0133] On the other hand, when a porous carbon material is used as a carbon support for supporting catalytic metal particles, the blocked pores contained in the carbon material are wasted space that cannot support the catalytic metal particles. Therefore, a relatively high true density of a porous carbon material reflects the small volume of the blocked pores in the carbon material, and means that the carbon material has a porous structure suitable for use as a carbon support for supporting catalytic metal particles.

[0134] Specifically, for example, when the support is a carbon material that has been graphitized and then oxidized, the pores that were closed by the graphitization process are reopened by the oxidation process, and the support has a higher true density than a carbon material that has been graphitized and not subsequently oxidized. This increase in true density due to the oxidation process increases the surface and space available for supporting catalytic metal particles on the support, thereby contributing to further improvement of the catalytic activity of metal-supported catalysts that include the support.

[0135] The upper limit of the true density of the carrier is not particularly limited as long as the effects of the present invention can be obtained. For example, 3 It may be less than 2.5 g / cm 3 It may be less than 2.4 g / cm 3 It may be less than 2.3 g / cm 3It may be less than 2.2 g / cm 3 may be less than 2.1 g / cm 3 The true density of the carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0136] The bulk density of the carrier may be 0.15 g / mL or more. The bulk density of the carrier is preferably 0.16 g / mL or more, more preferably 0.17 g / mL or more, even more preferably 0.18 g / mL or more, even more preferably 0.19 g / mL or more, even more preferably 0.20 g / mL or more, even more preferably 0.21 g / mL or more, and particularly preferably 0.22 g / mL or more. The bulk density of the carbon carrier is obtained by a bulk density measurement method using a measuring cylinder.

[0137] A bulk density of the present support equal to or greater than the above lower limit contributes to further improving the catalytic activity of a metal-supported catalyst containing the present support. That is, if the bulk density of the carbon support is too small, and the amount of electrolyte material mixed with the metal-supported catalyst containing the carbon support is reduced, the metal-supported catalyst containing the carbon support may not be sufficiently coated with the electrolyte material, resulting in insufficient formation of ion conduction paths and a decrease in the catalytic activity of the metal-supported catalyst.

[0138] In contrast, when the bulk density of the present carrier is not too small, even if the amount of electrolyte material mixed with the metal-supported catalyst including the present carrier is reduced, the metal-supported catalyst including the present carrier is likely to be sufficiently coated with the electrolyte material, and the catalytic activity of the metal-supported catalyst is more effectively maintained.

[0139] The upper limit of the bulk density of the carrier is not particularly limited as long as the effects of the present invention are obtained, but may be, for example, 0.35 g / mL or less, 0.32 g / mL or less, 0.30 g / mL or less, 0.28 g / mL or less, 0.26 g / mL or less, or 0.25 g / mL or less. The bulk density of the carrier may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0140] A bulk density of the present support equal to or less than the above upper limit contributes to further improving the catalytic activity of a metal-supported catalyst containing the present support. That is, if the bulk density of the carbon support is too high, the catalyst layer produced using the metal-supported catalyst containing the carbon support will be too dense. For example, when the metal-supported catalyst containing the carbon support is applied to a fuel cell, gas diffusion in the catalyst layer containing the metal-supported catalyst may be hindered, resulting in a decrease in the catalytic activity of the metal-supported catalyst.

[0141] On the other hand, if the bulk density of the present carrier is not too large, the catalyst layer produced using the metal-supported catalyst including the present carrier will not be too dense. Therefore, for example, when the metal-supported catalyst including the present carrier is applied to a fuel cell, gas diffusion in the catalyst layer including the metal-supported catalyst is effectively maintained, and the catalytic activity of the metal-supported catalyst is even more effectively maintained.

[0142] The carrier is a porous carbon material mainly composed of carbon. The carbon content of the carrier is not particularly limited as long as the effects of the present invention are obtained, but may be, for example, 70% by weight or more, preferably 75% by weight or more, more preferably 80% by weight or more, and particularly preferably 85% by weight or more.

[0143] The carbon content of the present support may be, for example, less than 100% by weight, 95% by weight or less, or 90% by weight or less. The carbon content of the present support may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values. The carbon content of the carbon support is obtained by elemental analysis (specifically, pyrolysis).

[0144] The carrier is preferably a carbonized material. The carbonized material is obtained by carbonizing a raw material containing organic matter. The organic matter content in the raw material for carbonization may be, for example, 5% by weight or more and 90% by weight or less, and preferably 10% by weight or more and 80% by weight or less.

[0145] The organic matter contained in the raw material is not particularly limited as long as it can be carbonized. The organic compound contained in the organic matter may be a polymer (e.g., a thermosetting resin and / or a thermoplastic resin) and / or an organic compound with a smaller molecular weight.

[0146] Specific examples of organic substances include polyacrylonitrile, polyacrylonitrile-polyacrylic acid copolymer, polyacrylonitrile-polymethyl acrylate copolymer, polyacrylonitrile-polymethacrylic acid copolymer, polyacrylonitrile-polymethacrylic acid-polymethallylsulfonic acid copolymer, polyacrylonitrile-polymethyl methacrylate copolymer, phenol resin, polyfurfuryl alcohol, furan, furan resin, phenol formaldehyde resin, melamine, melamine resin, epoxy resin, nitrogen-containing chelate resin (e.g., one or more selected from the group consisting of polyamine type, iminodiacetic acid type, aminophosphoric acid type, and aminomethylphosphonic acid type), polyamideimide resin, pyrrole, polypyrrole, polyvinylpyrrole, 3-methylpolypyrrole, acrylonitrile, polyvinylidene chloride, thiophene, oxazole, thiazole, pyrazole, vinylpyridine, polyvinylpyridine, The polymer may be one or more selected from the group consisting of pyridazine, pyrimidine, piperazine, pyran, morpholine, imidazole, 1-methylimidazole, 2-methylimidazole, quinoxaline, aniline, polyaniline, succinic acid dihydrazide, adipic acid dihydrazide, polysulfone, polyaminobismaleimide, polyimide, polyvinyl alcohol, polyvinyl butyral, benzimidazole, polybenzimidazole, polyamide, polyester, polylactic acid, polyether, polyether ether ketone, cellulose, carboxymethyl cellulose, lignin, chitin, chitosan, pitch, silk, wool, polyamino acid, nucleic acid, DNA, RNA, hydrazine, hydrazide, urea, salen, polycarbazole, polybismaleimide, triazine, polyacrylic acid, polyacrylic acid ester, polymethacrylic acid ester, polymethacrylic acid, polyurethane, polyamidoamine, and polycarbodiimide.

[0147] The present support preferably contains nitrogen. That is, the present support preferably contains nitrogen atoms (e.g., doped nitrogen atoms) in its carbon structure. The present support containing nitrogen is preferably a nitrogen-containing carbonized material. The nitrogen-containing carbonized material is obtained, for example, by carbonizing a raw material containing a nitrogen-containing organic substance. The nitrogen-containing organic substance preferably contains a nitrogen-containing organic compound. The nitrogen-containing organic compound is not particularly limited as long as it is an organic compound containing a nitrogen atom in its molecule. The nitrogen contained in the present support may be introduced by nitrogen doping treatment.

[0148] The present support is preferably a carbonized material obtained by carbonizing a raw material containing an organic substance and a metal. Specifically, the present support is, for example, a carbonized material obtained by carbonizing an infusible raw material containing an organic substance and a metal. In this case, the infusible raw material containing an organic substance and a metal is preferably prepared by first infusible a precursor containing the organic substance, and then mixing the metal with the infusible precursor. By preparing the raw materials in this order, it is possible to effectively produce a carbon support having the pore structure unique to this embodiment described above, even when the metal content in the raw material is reduced.

[0149] When the present support is a carbonized material obtained by carbonizing a raw material containing an organic substance and a metal, the present support may be a carbonized material that has been subjected to a metal removal treatment after carbonization. The metal removal treatment is a treatment for reducing the amount of metals derived from the raw material contained in the carbonized material. Specifically, the metal removal treatment is preferably, for example, an acid washing treatment and / or an electrolytic treatment.

[0150] When the present support is a carbonized material obtained by carbonizing a raw material containing an organic substance and a metal, the present support may contain a metal derived from the raw material of the carbonization (hereinafter, sometimes referred to as a "raw material metal"). In this case, the present support contains a metal inside the skeleton that constitutes its porous structure. That is, even if the present support is a carbonized material produced through a metal removal treatment as described above, the raw material metal remains inside the skeleton of the present support. The weight of the metal contained inside the skeleton of the present support may be greater than the weight of the metal contained on the surface of the skeleton of the present support.

[0151] The metal contained inside the framework of the present carrier can be detected, for example, by subjecting the framework to a surface etching treatment and analyzing the cross section exposed by the etching treatment. That is, in this case, when one particle of the present carrier is subjected to an etching treatment, the metal is detected on the cross section of the particle exposed by the etching treatment. The metal contained in the present carrier can be detected, for example, by inductively coupled plasma atomic emission spectroscopy of the present carrier.

[0152] The metal content of the carrier (the ratio of the weight of the metal contained in the carrier to the weight of the carrier not yet supporting catalytic metal particles) may be, for example, 0.000% by weight or more, 0.001% by weight or more, 0.002% by weight or more, or 0.003% by weight or more. The metal content of the carrier may be, for example, 1% by weight or less, 0.5% by weight or less, 0.1% by weight or less, 0.05% by weight or less, 0.01% by weight or less, 0.008% by weight or less, or 0.005% by weight or less. The metal content of the carrier may be specified by any combination of the above-mentioned lower limit and the above-mentioned upper limit. The metal content of the carrier can be determined, for example, by inductively coupled plasma atomic emission spectroscopy of the carrier.

[0153] The raw material metal is preferably a metal belonging to Groups 2 to 14 of the periodic table, and particularly preferably a metal belonging to Periods 2 to 6 of Groups 2 to 14 of the periodic table. Specifically, the raw material metal may be, for example, one or more selected from the group consisting of calcium (Ca), magnesium (Mg), aluminum (Al), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), tin (Sn), lanthanides (e.g., gadolinium (Gd)), lead (Pb), and actinides. Preferably, the raw material metal is one or more selected from the group consisting of Ca, Mg, Al, Zn, Ag, Sn, and Pb. Particularly preferably, the raw material metal is one or more selected from the group consisting of Ca, Mg, Zn, and Sn.

[0154] The source metal may be, for example, a metal other than platinum. The source metal may be, for example, a metal other than a noble metal (for example, ruthenium (Ru), palladium (Pd), rhodium (Rh), silver (Ag), osmium (Os), iridium (Ir), platinum (Pt), and gold (Au)).

[0155] The carrier, which has not yet supported catalytic metal particles, may not contain platinum (Pt). The carrier, which has not yet supported catalytic metal particles, may not contain a precious metal. That is, the carrier may not contain, for example, ruthenium (Ru), palladium (Pd), rhodium (Rh), silver (Ag), osmium (Os), iridium (Ir), platinum (Pt), or gold (Au).

[0156] Carbonization in the production of a carbonized material is carried out by heating the raw material at a temperature at which the organic matter contained in the raw material is carbonized. The carbonization temperature is not particularly limited as long as it is a temperature at which the raw material is carbonized, and is, for example, preferably 1200°C or higher, more preferably 1300°C or higher, even more preferably 1400°C or higher, and particularly preferably 1500°C or higher.

[0157] The carbonization temperature may be, for example, 3000°C or lower, and preferably 2500°C or lower. The carbonization temperature may be 2400°C or lower, 2300°C or lower, 2200°C or lower, 2100°C or lower, 2000°C or lower, 1900°C or lower, 1800°C or lower, 1700°C or lower, or 1600°C or lower. The carbonization temperature may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values. The rate of temperature rise to the carbonization temperature is not particularly limited and may be, for example, 0.5°C / min or higher and 300°C / min or lower. Carbonization is preferably performed in an inert atmosphere such as a nitrogen atmosphere.

[0158] Carbonization is preferably carried out under pressure (under a pressure higher than atmospheric pressure). In this case, the pressure of the atmosphere in which carbonization is carried out may be, for example, 0.05 MPa or more in gauge pressure, preferably 0.15 MPa or more in gauge pressure, more preferably 0.20 MPa or more, even more preferably 0.40 MPa or more, and particularly preferably 0.50 MPa or more. The upper limit of the pressure of the atmosphere in which carbonization is carried out is not particularly limited, but the pressure may be, for example, 10 MPa or less in gauge pressure.

[0159] The present support is preferably a carbonized material that has been subjected to a graphitization treatment after carbonization, i.e., the present support is preferably a carbonized material obtained by, for example, carbonizing a raw material containing an organic substance and then graphitizing the carbonized material.

[0160] The graphitization treatment is carried out by heating the carbonized material at a temperature at which graphitization proceeds. The heating temperature at which the carbonized material is heated in the graphitization treatment is not particularly limited as long as it is a temperature at which graphitization proceeds in the carbonized material, but is preferably a temperature higher than the carbonization temperature for obtaining the carbonized material.

[0161] Specifically, the heating temperature in the graphitization treatment may be, for example, 1300° C. or higher, preferably 1400° C. or higher, more preferably 1500° C. or higher, even more preferably 1600° C. or higher, still more preferably 1650° C. or higher, and particularly preferably 1700° C. or higher. In addition, the heating temperature in the graphitization treatment may be, for example, 3000° C. or lower, 2500° C. or lower, 2000° C. or lower, 1900° C. or lower, or 1800° C. or lower.

[0162] The heating temperature in the graphitization treatment may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values. The rate of temperature increase up to the heating temperature in the graphitization treatment is not particularly limited and may be, for example, 0.5°C / min or more and 300°C / min or less. The graphitization treatment is preferably performed in an inert atmosphere such as a nitrogen atmosphere.

[0163] When the present support is a carbonized material that has been graphitized after carbonization, it is preferable that the carbonized material after the graphitization is not subjected to a pulverization treatment. That is, in the production of the present support, for example, the carbonized material obtained by carbonizing a raw material is pulverized to adjust its particle size (e.g., median diameter), and then the pulverized carbonized material is graphitized, but the carbonized material after the graphitization is not subjected to a pulverization treatment.

[0164] The present support is preferably a carbonized material that has been subjected to a graphitization treatment and then an oxidation treatment. That is, the present support is preferably a carbonized material obtained, for example, by carbonizing a raw material containing an organic substance, subjecting the carbonized material to a graphitization treatment, and then further subjecting the carbonized material to an oxidation treatment.

[0165] The oxidation treatment is carried out by heating the carbonized material in an oxygen-containing atmosphere at a temperature at which oxidation proceeds. The atmosphere in which the oxidation treatment is carried out is not particularly limited as long as it contains oxygen, but is preferably, for example, air (atmospheric air). The heating temperature at which the carbonized material is heated in the oxidation treatment is not particularly limited as long as it is a temperature at which oxidation proceeds in the carbonized material, but is preferably a temperature lower than the carbonization temperature for obtaining the carbonized material.

[0166] Specifically, the heating temperature in the oxidation treatment may be, for example, 300°C or higher, preferably 320°C or higher, more preferably 350°C or higher, even more preferably 380°C or higher, still more preferably 400°C or higher, and particularly preferably 420°C or higher. The heating temperature in the oxidation treatment may be, for example, 650°C or lower, preferably 600°C or lower, more preferably 550°C or lower, even more preferably 500°C or lower, and particularly preferably 480°C or lower. The heating temperature in the oxidation treatment may be specified by any combination of any of the above-mentioned lower limit values ​​and any of the above-mentioned upper limit values.

[0167] The present support is preferably a carbon material that exhibits catalytic activity. That is, in this case, the present support is a carbon catalyst that exhibits catalytic activity by itself. The present support, which is a carbon catalyst, is preferably a carbonized material obtained by carbonizing a raw material containing an organic substance and a metal, as described above. The catalytic activity exhibited by the present support is preferably, for example, reduction activity and / or oxidation activity, more preferably oxygen reduction activity and / or hydrogen oxidation activity, and particularly preferably at least oxygen reduction activity.

[0168] The metal-supported catalyst according to this embodiment (hereinafter referred to as "the catalyst") includes the carrier and catalytic metal particles supported on the carrier. The catalyst is produced by supporting the catalytic metal particles on the carrier. That is, for example, the carrier is impregnated with a precursor of the metal that constitutes the catalytic metal particles, and then the carrier impregnated with the precursor is subjected to a reduction treatment, thereby supporting the catalytic metal particles containing the metal on the carrier.

[0169] The catalytic metal particles are not particularly limited as long as they are metal particles that exhibit catalytic activity, but for example, they are preferably metal particles that exhibit reduction activity and / or oxidation activity, more preferably metal particles that exhibit oxygen reduction activity and / or hydrogen oxidation activity, and particularly preferably metal particles that exhibit at least oxygen reduction activity.

[0170] Specifically, the catalytic metal particles are preferably metal particles containing a precious metal (hereinafter referred to as "precious metal particles"). The precious metal particles contain a pure precious metal (a precious metal that is not alloyed) and / or a precious metal alloy (an alloy of a precious metal and a metal other than a precious metal (hereinafter referred to as "non-precious metal"). The precious metal alloy is an alloy of one or more precious metals and one or more non-precious metals.

[0171] The noble metal is preferably at least one selected from the group consisting of ruthenium (Ru), palladium (Pd), rhodium (Rh), silver (Ag), osmium (Os), iridium (Ir), platinum (Pt), and gold (Au), more preferably at least one selected from the group consisting of Ru, Pd, Rh, Ir, and Pt, and particularly preferably Pt. That is, the noble metal particles are particularly preferably platinum particles (metal particles containing platinum). The platinum particles include pure platinum (unalloyed platinum) and / or a platinum alloy (an alloy of platinum and a non-noble metal).

[0172] The non-precious metal constituting the precious metal alloy is not particularly limited as long as it forms an alloy with the precious metal, but is preferably a transition metal other than a precious metal. Specifically, the non-precious metal contained in the precious metal alloy is preferably one or more selected from the group consisting of titanium (Ti), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), niobium (Nb), and cerium (Ce), more preferably one or more selected from the group consisting of Fe, Co, and Ni, and particularly preferably one or more selected from the group consisting of Co and Ni.

[0173] When the support is a carbonized material of a raw material containing an organic substance and a raw material metal, the catalytic metal particles supported on the support may contain the same type of metal as the raw material metal, or may not contain the same type of metal as the raw material metal.

[0174] The catalyst preferably has a weight ratio (hereinafter referred to as "precious metal content") of the precious metal contained in the catalyst (more specifically, the precious metal contained in the catalytic metal particles) to the weight of the catalyst of 10% by weight or more. The precious metal content of the catalyst is, for example, more preferably 20% by weight or more, even more preferably 30% by weight or more, even more preferably 35% by weight or more, even more preferably 40% by weight or more, and particularly preferably 45% by weight or more. The precious metal content of the catalyst may be, for example, 90% by weight or less, 80% by weight or less, 70% by weight or less, or 60% by weight or less. The precious metal content of the catalyst may be specified by any combination of the above-mentioned lower limit and any of the above-mentioned upper limit. The precious metal content of the catalyst is measured by inductively coupled plasma (ICP) atomic emission spectroscopy.

[0175] The electrode according to this embodiment (hereinafter referred to as "the electrode") contains the catalyst of the present invention. That is, the electrode of the present invention includes, for example, an electrode substrate and the catalyst of the present invention supported on the electrode substrate. Specifically, the electrode of the present invention includes, for example, an electrode substrate and a catalyst layer containing the catalyst of the present invention formed on the electrode substrate.

[0176] The catalyst layer of the electrode contains the catalyst and an electrolyte material. That is, the catalyst layer is formed, for example, by applying a composition prepared by mixing the catalyst and the electrolyte material to an electrode substrate and drying the composition. The electrolyte material to be mixed with the catalyst is not particularly limited as long as the effects of the present invention can be obtained, but for example, an electrolyte material (e.g., ionomer) having an EW value of 300 or more and 1000 or less is preferably used.

[0177] By using an electrolyte material having an EW value within the above range, efficient supply of oxygen and protons to the catalyst can be achieved, for example, in a fuel cell cathode. The EW value of an electrolyte material is the equivalent weight, which is the number of grams of the electrolyte material in a dry state per mole of sulfonic acid group.

[0178] The ratio of the present catalyst to the electrolyte material in the catalyst layer of the present electrode is not particularly limited as long as the effects of the present invention are obtained, and may be determined appropriately depending on, for example, the characteristics of the present catalyst and / or the characteristics of the electrolyte material. Specifically, the ratio of the weight of the present carrier contained in the present catalyst in the catalyst layer of the present electrode to the weight of the electrolyte material contained in the catalyst layer may be, for example, within a range of 0.1 to 2.0, within a range of 0.3 to 1.7, within a range of 0.5 to 1.5, or within a range of 0.7 to 1.3.

[0179] The type of electrolyte material contained in the catalyst layer of this electrode is not particularly limited as long as the effects of the present invention are obtained, but the electrolyte material is preferably, for example, a perfluorocarbon material or a hydrocarbon-based material. Specifically, the electrolyte material may be, for example, a perfluorocarbon sulfonic acid-based polymer. In this case, the electrolyte material is preferably, for example, a perfluorocarbon material having a polytetrafluoroethylene skeleton and sulfonic acid groups. More specifically, the electrolyte material may be, for example, one or more selected from the group consisting of NAFION (trademark), AQUIVION (trademark), ACIPLEX (trademark), and FLEMION (trademark).

[0180] The electrode is preferably a battery electrode. That is, the electrode is preferably an electrode of, for example, a fuel cell (e.g., a polymer electrolyte fuel cell), an air cell, a water electrolyzer (e.g., a polymer electrolyte water electrolyzer), a redox flow battery, or a halogen battery. The electrode may be either a cathode or an anode, but is preferably a cathode. That is, the electrode is a cathode or anode of a fuel cell, an air cell, a water electrolyzer, a redox flow battery, or a halogen battery, and is preferably a cathode.

[0181] The battery according to this embodiment (hereinafter referred to as "this battery") includes this electrode. Specifically, this battery is preferably a fuel cell (e.g., a polymer electrolyte fuel cell), an air battery, a redox flow battery, or a halogen battery that includes this electrode. This battery preferably has a membrane electrode assembly (MEA) that includes this electrode.

[0182] The present battery is a battery having the present electrode as a cathode or an anode, preferably a battery having the present electrode as a cathode. That is, the present battery is a fuel cell, air battery, redox flow battery, or halogen battery having the present electrode as a cathode or an anode, preferably a fuel cell, air battery, redox flow battery, or halogen battery having the present electrode as a cathode.

[0183] Next, a specific example according to this embodiment will be described. [Example]

[0184] [Production of carbon support: Example 1] 1.0 g of polyacrylonitrile, 1.5 g of 2-methylimidazole, and 30 g of dimethylformamide were mixed. The resulting mixture was dried to remove the solvent. The dried mixture was heated in air at 250°C to make it infusible.

[0185] The infusibilized mixture was mixed with an aqueous solution prepared by dissolving 2.0 g of zinc chloride (ZnCl2) in 30 g of water, and the solvent was removed from the resulting mixture by drying to obtain a raw material for carbonization.

[0186] The raw material obtained as described above was carbonized by heating it at 1500°C under a gauge pressure (applied pressure) of 0.90 MPa in a nitrogen atmosphere. Dilute hydrochloric acid was added to the carbonized material obtained by carbonization and stirred. Thereafter, the suspension containing the carbonized material was filtered using a filtration membrane, and the carbonized material was washed with distilled water until the filtrate became neutral. In this way, a metal removal treatment by acid washing was performed.

[0187] The carbonized material after the metal removal treatment was pulverized in a fine pulverizer until the median particle size was 0.4 μm or less. The pulverized carbonized material was vacuum dried to remove moisture.

[0188] The carbonized material thus obtained was graphitized by heating it at 1700°C under normal pressure in a nitrogen atmosphere. Furthermore, the carbon support after the graphitization treatment was oxidized by heating it in air at 450°C for 1 hour.

[0189] The carbonized material thus obtained by carbonizing the raw material having a relatively small content of metals added after the infusibilization was subjected to a graphitization treatment at 1700°C, and then further subjected to an oxidation treatment. The resulting carbonized material was used as the carbon support of Example 1.

[0190] [Production of carbon support: Example 2] A carbonized material obtained by carbonizing a raw material having a relatively small content of metals added after infusibilization was subjected to a graphitization treatment at 1800°C in the same manner as in Example 1 above, except that the graphitization temperature was 1800°C instead of 1700°C, and then further subjected to an oxidation treatment, and the obtained carbonized material was used as the carbon support in Example 2.

[0191] [Production of carbon support: Example 3] A carbonized material obtained by carbonizing a raw material having a relatively small content of metals added after infusibilization was subjected to a graphitization treatment at 1700°C and then further subjected to an oxidation treatment in the same manner as in Example 1 above, except that 2.8 g of tin chloride (SnCl) was used instead of 2.0 g of zinc chloride (ZnCl). The carbonized material was used as the carbon support in Example 3.

[0192] [Production of carbon support: Example C1] 1.0 g of polyacrylonitrile, 1.5 g of 2-methylimidazole, 2.0 g of zinc chloride (ZnCl2), and 30 g of dimethylformamide were mixed. The resulting mixture was dried to remove the solvent. The dried mixture was heated in air at 250°C to infusibly form the raw material for carbonization.

[0193] The raw material obtained as described above was carbonized by heating it at 1500°C under a gauge pressure (applied pressure) of 0.90 MPa in a nitrogen atmosphere. Dilute hydrochloric acid was added to the carbonized material obtained by carbonization and stirred. Then, the suspension containing the carbonized material was filtered using a filter membrane, and the carbonized material was washed with distilled water until the filtrate became neutral. In this way, a metal removal treatment by acid washing was performed. The carbonized material after the metal removal treatment was pulverized using a fine pulverizer until the median particle diameter was 0.4 μm or less. The pulverized carbonized material was vacuum dried to remove moisture.

[0194] The carbonized material thus obtained was graphitized by heating it at 1700°C under normal pressure in a nitrogen atmosphere. Furthermore, the carbon support after the graphitization treatment was oxidized by heating it in air at 450°C for 1 hour.

[0195] The carbonized material thus obtained by carbonizing the raw material having a relatively small content of metals added before the infusibilization was subjected to a graphitization treatment at 1700°C, and then further subjected to an oxidation treatment. The resulting carbonized material was used as the carbon support of Example C1.

[0196] [Production of carbon support: Example C2] 1.0 g of polyacrylonitrile, 1.0 g of 2-methylimidazole, 3.3 g of zinc chloride (ZnCl2), and 30 g of dimethylformamide were mixed. The solvent was removed from the resulting mixture by drying. The dried mixture was heated in air at 250°C to infusible it, and the raw material for carbonization was obtained.

[0197] The raw material obtained as described above was carbonized by heating it at 1500°C under a gauge pressure (applied pressure) of 0.90 MPa in a nitrogen atmosphere. Dilute hydrochloric acid was added to the carbonized material obtained by carbonization and stirred. Then, the suspension containing the carbonized material was filtered using a filter membrane, and the carbonized material was washed with distilled water until the filtrate became neutral. In this way, a metal removal treatment by acid washing was performed. The carbonized material after the metal removal treatment was pulverized using a fine pulverizer until the median particle diameter was 0.4 μm or less. The pulverized carbonized material was vacuum dried to remove moisture.

[0198] The carbonized material thus obtained by carbonizing a raw material having a relatively large content of metals added before infusibilization and not subjected to graphitization or oxidation treatment after carbonization was used as the carbon support in Example C2.

[0199] [Production of carbon support: Example C3] The carbon support obtained in Example C2 above was graphitized by heating it in a nitrogen atmosphere at normal pressure at 1700°C. The graphitized carbon support was then oxidized by heating it in air at 450°C for 1 hour.

[0200] The carbonized material thus obtained by carbonizing the raw material having a relatively large content of metals added before the infusibilization was subjected to a graphitization treatment at 1700°C, and then further subjected to an oxidation treatment. The resulting carbonized material was used as the carbon support of Example C3.

[0201] [Production of carbon support: Example C4] The carbon support obtained in Example C2 above was graphitized by heating it at 2000° C. under normal pressure in a nitrogen atmosphere.

[0202] The carbonized material thus obtained by carbonizing the raw material having a relatively large content of metals added before the infusibilization was subjected to a graphitization treatment at 2000°C, and the carbonized material obtained without being subjected to a subsequent oxidation treatment was used as the carbon support of Example C4.

[0203] [Production of carbon support: Example C5] A commercially available carbon black, Ketjenblack (EC600JD, manufactured by Lion Specialty Chemicals Co., Ltd.), was used as the carbon support in Example C5.

[0204] [Production of carbon support: Example C6] A commercially available carbon black, Ketjenblack (EC300J, manufactured by Lion Specialty Chemicals Co., Ltd.), was used as the carbon support in Example C6.

[0205] [Production of carbon support: Example C7] A commercially available carbon black, BLACK PEARLS™ 2000 (Cabot Corporation), was used as the carbon support in Example C7.

[0206] [Nitrogen adsorption method] The log differential pore volume, most frequent diameter, pore volume, specific surface area, and hysteresis in the nitrogen adsorption isotherm of the carbon support were measured using a specific surface area and pore size distribution analyzer (TriStar II 3020, Shimadzu Corporation) and the accompanying analysis software (TriStar II 3020).

[0207] First, 0.1 g of carbon support was heated at 100°C for 6.7 × 10 -2 The carbon support was then held at 77 Pa for 3 hours to remove moisture adsorbed to the support. Next, a nitrogen adsorption isotherm at 77 K was obtained by the BET method. This nitrogen adsorption isotherm at 77 K was obtained by measuring the change in the amount of nitrogen adsorbed to the carbon support with a change in nitrogen gas pressure at a temperature of 77 K.

[0208] The nitrogen adsorption isotherm thus obtained is, for example, plotted on the horizontal axis as saturated vapor pressure (P0) (1.01 × 10 for nitrogen at 77 K). 5 The vertical axis shows the relative pressure (P / P0) (-), which is the ratio of the adsorption equilibrium pressure (P) to the adsorption equilibrium pressure (Pa), and the vertical axis shows the nitrogen adsorption amount (cm 3 The nitrogen adsorption isotherm is shown as a graph showing the adsorption isotherm (adsorption isotherm measured while increasing the relative pressure) and the desorption isotherm (adsorption isotherm measured while decreasing the relative pressure).

[0209] In the nitrogen adsorption isotherm obtained for each carbon support, the hysteresis (0.5P / P) (cm 3 Similarly, the hysteresis (0.8P / P) (cm ) was calculated by subtracting the amount of nitrogen adsorption from the amount of nitrogen desorption at a relative pressure (P / P) of 0.8. 3 / g) was calculated.

[0210] In addition, the specific surface area (m 2 The volume (cm3) of each pore in the carbon support with a pore diameter in the range of more than 0 nm and 70 nm or less was also obtained from the nitrogen adsorption isotherm at 77 K using the DFT method. 3 / g), the volume of pores with diameters greater than 0 nm and less than 70 nm (pore volume (0-70 nm)) (cm 3 / g) was calculated.

[0211] Similarly, the volume (cm) of each pore with a pore diameter in the range of more than 0 nm and less than 2 nm 3 / g), the volume of pores with diameters less than 2 nm (pore volume (#<2 nm)) (cm 3 / g) was calculated. The volume (cm) of each pore with a diameter of more than 0 nm and less than 5 nm was also calculated. 3 / g), the volume of pores with diameters less than 5 nm (pore volume (#<5 nm)) (cm 3 / g) was calculated.

[0212] Similarly, the volume (cm) of each pore with a pore diameter in the range of 2 nm or more and 10 nm or less 3 / g), the volume of pores with diameters in the range of 2 nm to 10 nm (pore volume (#2-10 nm)) (cm 3 The volume (cm3) of each pore with a diameter of 5 nm or more and 70 nm or less was calculated. 3 / g), the volume of pores with diameters in the range of 5 nm to 70 nm (pore volume (#5-70 nm)) (cm 3 / g) was calculated.

[0213] Also, pore volume (#0-70nm) (cm 3 / g) vs. pore volume (#<5nm) (cm 3 The ratio (-) of the pore volume ratio (#5 / (0-70 nm)) was calculated as the pore volume ratio (#5 / (0-70 nm)). That is, the pore volume ratio (#5 / (0-70 nm)) was calculated as the pore volume (#<5 nm) (cm) of each carbon support. 3 / g) is calculated by dividing the pore volume (0-70 nm) (cm 3 / g). Similarly, the pore volume (#5-70 nm) (cm 3 / g) vs. pore volume (#<5nm) (cm 3 / g) ratio (-) was calculated as the pore volume ratio (#5 / (5-70 nm)).

[0214] Furthermore, the Log differential pore volume distribution of the carbon support was obtained by the DFT method from the nitrogen adsorption isotherm at a temperature of 77 K. FIG. 1A shows the Log differential pore volume distribution obtained for the carbon support of Examples 1, 2, and 3 ("Example 1," "Example 2," and "Example 3" in the figure). FIG. 1B shows the Log differential pore volume distribution obtained for the carbon support of Examples C1, C2, C3, and C4 ("Example C1," "Example C2," "Example C3," and "Example C4" in the figure). FIG. 1C shows the Log differential pore volume distribution obtained for the carbon support of Examples C5, C6, and C7 ("Example C5," "Example C6," and "Example C7" in the figure). In FIGS. 1A, 1B, and 1C, the horizontal axis represents the pore diameter ("Pore diameter" in the figure) (nm), and the vertical axis represents the Log differential pore volume ("dV / d(logD)" in the figure) (cm). 3 / g).

[0215] In the Log differential pore volume distribution of each carbon support, the pore diameter giving the maximum value of the Log differential pore volume within the pore diameter range of more than 0 nm and not more than 70 nm was identified as the most frequent diameter (nm).

[0216] [Raman spectroscopy] The carbon support was analyzed by Raman spectroscopy. The Raman spectrum was measured using a HORIBA microscopic laser Raman spectrometer (LabRAM, HORIBA Jobin Yvon). The laser used for the measurement had an excitation wavelength of 532 nm and an output of 50 mW. The Raman spectrum was obtained by measuring through a neutral density filter D3 under the conditions of 90 seconds of exposure x 2 accumulations.

[0217] The obtained Raman spectra were subjected to baseline correction. -1 ) is 800cm -1 Scattering intensity near 2000cm -1 A straight line connecting nearby scattering intensities was determined as the baseline, and baseline correction was performed by subtracting the baseline from each intensity of the scattering spectrum.

[0218] and Raman shift 1580cm -1 Around (specifically, 1550 cm -1 Over, 1610cm -1 The G band with a peak top within the range of 1000 to 10000 was identified. g Raman shift (cm) corresponding to (peak top intensity of G band) -1 )A g From the above, the intensity of the G band I g The Raman shift (cm) corresponding to half the intensity of -1 )B g By subtracting -1 ) was calculated. That is, the Raman G half-width at half maximum of the carbon support was calculated by the following formula: Raman G half-width at half maximum (cm -1 )=A g (cm -1 )-B g (cm -1 ).

[0219] In addition, the Raman shift is 1340 cm -1 Around (specifically, 1320 cm -1 Above, 1360cm -1 The D band with a peak top in the range of 1000 to 15000 was identified. d (D band peak top intensity) -1 )A d From the above, the intensity of the D band I d The Raman shift (cm) corresponding to half the intensity of -1 )B d By subtracting the Raman D half-width at half maximum (cm -1 ) was calculated. That is, the Raman D half-width at half maximum of the carbon support was calculated by the following formula: Raman D half-width at half maximum (cm -1 )=A d (cm -1 )-B d (cm -1 ).

[0220] Furthermore, the Raman shift of 2700 cm -1around (specifically, 2650 cm -1 More than 2750cm -1 The 2D bands with peak tops within the range of I 2d Raman shift (cm) corresponding to (peak top intensity of 2D band) -1 )A 2d from the intensity of the 2D band, I 2d The Raman shift (cm) corresponding to half the intensity of -1 )B 2d By subtracting the Raman 2D half-width at half maximum (cm -1 ) was calculated. That is, the Raman 2D half-width at half maximum of the carbon support was calculated by the following formula: Raman 2D half-width at half maximum (cm -1 )=A 2d (cm -1 )-B 2d (cm -1 ).

[0221] In addition, the D-band intensity I d is the G-band intensity I g The Raman D / G ratio was calculated by dividing the Raman D / G ratio by . That is, the Raman D / G ratio of the carbon support was calculated by the following formula: Raman D / G ratio = I d / I g .

[0222] Also, the intensity of the 2D band I 2d is the G-band intensity I g The Raman 2D / G ratio was calculated by dividing the Raman 2D / G ratio by 1. That is, the Raman 2D / G ratio of the carbon support was calculated by the following formula: Raman 2D / G ratio = I 2d / I g .

[0223] [Oxygen content and nitrogen content] The oxygen and nitrogen contents of the carbon support were measured by elemental analysis (pyrolysis method). Specifically, 2 mg of the carbon support was pyrolyzed on a carbon-coated platinum plate at 1000°C in a helium / hydrogen atmosphere (5-8% by volume of hydrogen) using an organic trace elemental analyzer (2400II, PerkinElmer Co., Ltd.), and the oxygen-containing compounds (gases) produced by the pyrolysis were analyzed to obtain the oxygen content (wt%) and nitrogen content (wt%) of the carbon support.

[0224] [True density] The true density of the carbon support was measured by a constant volume expansion method in accordance with JIS M 8717. Specifically, an ultrapycnometer (UP-1200e, manufactured by Anton Paar) was used to measure the true density of a carbon support with a volume of 1.8 cm. 3 The volume of helium gas displaced by filling the sample chamber with the carbon support was calculated by Boyle's law. Such measurements were carried out three times for each carbon support, and the arithmetic mean value of the volumes obtained in the three measurements was obtained as the volume of the carbon support. The weight (g) of the carbon support measured by the electronic balance was then multiplied by the volume (cm) of the carbon support obtained as described above. 3 ) to obtain the true density (g / cm 3 ) was calculated.

[0225] [Bulk density] The bulk density of the carbon support was measured using a bulk density measurement method using a measuring cylinder. Specifically, 1 g of carbon support was weighed and placed in a 10 mL measuring cylinder. The measuring cylinder containing the carbon support was placed on a vortex mixer (Genie 2, Scientific Industries, Inc.) and mixed at an intensity of 5 or higher. While continuing to mix the carbon support in the measuring cylinder, the mixing intensity was gradually reduced. After confirming that the volume of the carbon support no longer changed, the vortex mixer was stopped. Note that during this operation, mixing at each mixing intensity was continued for 10 seconds or more. The bulk density (g / mL) of the carbon support was calculated by dividing the weight (g) of the carbon support by the volume (mL) of the carbon support read from the measuring cylinder after mixing was stopped.

[0226] [Production of metal-supported catalysts] Metal-supported catalysts were produced by loading metal catalyst particles onto each of the carbon supports described above. Specifically, 1 g of each carbon support was mixed with 10 g of an aqueous solution containing chloroplatinic acid (HPtCl), a platinum precursor, in an amount sufficient to achieve a platinum concentration of 10 wt% (platinum content per gram). The mixture was stirred for 1 hour under a gauge pressure of -0.1 MPa (reduced pressure), then for 1 hour under a gauge pressure of 0.15 MPa (overpressure), and then for 18 hours under normal pressure. The resulting mixture was then dried at 100°C under a gauge pressure of -0.1 MPa (reduced pressure), and then further maintained at 150°C in nitrogen to volatilize the solvent components.

[0227] The obtained solid was first subjected to a heat treatment (gas phase reduction treatment) at 350°C for 180 minutes in a hydrogen atmosphere (100% by volume of hydrogen gas). The treated solid was then subjected to a heat treatment at 700°C for 180 minutes in a nitrogen atmosphere (100% by volume of nitrogen gas). In this way, a metal-supported catalyst was obtained, which included a carbon support and platinum particles supported on the carbon support as catalytic metal particles.

[0228] [Power generation test] To evaluate one aspect of the performance of the metal-supported catalyst, a power generation test was conducted on a fuel cell having an electrode containing the metal-supported catalyst. That is, a cell cathode having a catalyst layer containing the metal-supported catalyst was first fabricated.

[0229] Specifically, to 0.25 g of the metal-supported catalyst produced as described above, an ionomer (AQUIVION (trademark) D83-24B, equivalent weight EW=830) was added as an electrolyte material in an amount such that the weight ratio to the carbon support contained in the metal-supported catalyst (hereinafter referred to as the "I / C ratio") was 1.1 or 0.7, and further 2 g each of distilled water and 1-propanol were added to prepare two types of electrolyte solutions with different I / C ratios.

[0230] Next, each of the two types of electrolyte solutions and 25 g of balls were placed in a pot and mixed in a ball mill at 200 rpm for 50 minutes, thereby obtaining two types of slurry-like compositions for catalyst layers containing uniformly dispersed metal-supported catalysts and having different I / C ratios.

[0231] Each of the two types of slurry catalyst layer compositions obtained was applied to a gas diffusion layer ("28BC", manufactured by SGL Carbon Co., Ltd.) (2.3 cm x 2.3 cm) with an area of ​​5 cm. 2 The platinum content per unit area of ​​the battery electrode contained in the catalytic metal particles supported on the metal-supported catalyst is 0.2 mg-Pt / cm 2 A catalyst layer was formed on the gas diffusion layer by applying the coating solution so that the coating was in a ratio of 1.1 to 1.2 and drying the coating solution. In this way, a battery cathode was obtained in which a catalyst layer containing the metal-supported catalyst and the electrolyte material and having an I / C ratio of 1.1 was formed, and a battery cathode was obtained in which a catalyst layer containing the metal-supported catalyst and the electrolyte material and having an I / C ratio of 0.7 was formed.

[0232] Next, a fuel cell including an electrode on which a catalyst layer containing a metal-supported catalyst was formed was manufactured. That is, the cell cathode on which a catalyst layer (positive electrode catalyst layer) containing a metal-supported catalyst formed as described above was used as the positive electrode.

[0233] On the other hand, the negative electrode was prepared as follows. 0.5 g of a commercially available platinum-supported catalyst Pt / C (a catalyst containing platinum particles supported on a carbon support: platinum-supported carbon Pt / ECP, manufactured by Ishifuku Metal Industries Co., Ltd.), 10 g of 5% Nafion (registered trademark), 2 g of distilled water, and 25 g of balls were placed in a pot and mixed in a ball mill at 200 rpm for 50 minutes to prepare a Pt / C composition slurry. This Pt / C composition slurry was applied to a gas diffusion layer (5 cm 2 ) with a platinum content of 0.1 mg-Pt / cm 2 A battery anode including a catalyst layer (negative electrode catalyst layer) formed from the Pt / C composition was fabricated in the same manner as the positive electrode, except that the above-mentioned condition was satisfied.

[0234] A solid polymer electrolyte membrane (Nafion (registered trademark) 211 manufactured by DuPont) was then placed between the positive electrode catalyst layer and the negative electrode catalyst layer, and these were pressure-bonded at 150°C and 1 MPa for 3 minutes to produce an MEA. A pair of gaskets was attached to this MEA, which was then sandwiched between a pair of separators to produce a single fuel cell cell for power generation tests. This single cell was then installed in an automated fuel cell evaluation system (manufactured by Toyo Corporation) and a power generation test was performed.

[0235] In the power generation test, saturated humidified air (oxygen) was supplied to the positive electrode side at 2.5 L / min (relative humidity 100%) with a back pressure of 150 kPa, and saturated humidified hydrogen was supplied to the negative electrode side at 1.0 L / min (relative humidity 100%). The cell temperature was set to 75°C, and the open circuit voltage was measured for 5 minutes. After that, the cell current density was set to 4.0 A / cm. 2 to 0 A / cm 2 The cell voltage was measured while maintaining each current density for 3 minutes.

[0236] Then, under 100% relative humidity, the current density was 0.2 A / cm 2 The voltage (mV) measured at this temperature was used as the "BOL (Beginning of Life) (0.2A / cm)", which is one of the indicators of initial catalytic activity. 2 ) (mV). Also, under 100% relative humidity, the current density was 1.0 A / cm 2 The voltage (mV) measured at the initial catalyst activity was used as the "BOL (1.0 A / cm 2 ) (mV).

[0237] The BOL (0.2 A / cm) obtained using a battery cathode with an I / C ratio of 1.1 was 2 ) (mV) versus the BOL (#0.2A / cm2) obtained using a battery cathode with an I / C ratio of 0.7 2 ) (mV) ratio is used as the BOL maintenance rate (#0.2A / cm 2 )(-).

[0238] That is, the BOL maintenance rate (#0.2A / cm 2) is the BOL (0.2A / cm) obtained using a battery cathode with an I / C ratio of 0.7. 2 ) (mV) was calculated using the BOL (#0.2 A / cm) obtained using a battery cathode with an I / C ratio of 1.1. 2 ) (mV).

[0239] Similarly, the BOL (1.0 A / cm) obtained using a battery cathode with an I / C ratio of 1.1 2 ) (mV) versus the BOL (#1.0 A / cm) obtained using a battery cathode with an I / C ratio of 0.7 2 ) (mV) is used as the BOL maintenance rate (#1.0A / cm 2 )(-).

[0240] The BOL retention rate (-) indicates the degree to which the BOL (mV) of a fuel cell containing a metal-supported catalyst as an electrode catalyst is maintained when the amount of ionomer mixed with the metal-supported catalyst is reduced from an amount that results in an I / C ratio of 1.1 to an amount that results in an I / C ratio of 0.7. Therefore, a metal-supported catalyst with a higher BOL retention rate maintains a higher level of catalytic activity even when the amount of ionomer is reduced.

[0241] [result] Figure 2A shows the results of evaluating some of the properties of the carbon support, and Figure 2B shows the results of evaluating other properties of the carbon support and the performance of the metal-supported catalyst.

[0242] As shown in FIG. 2B, the BOL (mV) of the metal-supported catalysts containing carbon supports of Examples 1 to 3 when the I / C ratio was 0.7 ("BOL(#I / C=0.7)" in the figure) was 0.2 A / cm 2 and 1.0 A / cm 2 In all of the current densities, the current densities were significantly higher than those of the metal-supported catalysts containing the carbon supports of Examples C1 to C7.

[0243] That is, the metal-supported catalysts containing a carbon support in Examples 1 to 3 exhibited significantly higher catalytic activity than the metal-supported catalysts containing a carbon support in Examples C1 to C7 when the weight ratio of ionomer to carbon support was relatively small.

[0244] In addition, the BOL maintenance rate of the metal-supported catalysts containing carbon supports in Examples 1 to 3 ("BOL maintenance rate (#I / C=0.7→1.1)" in the figure) (-) was 0.2 A / cm 2 The current density was higher than that of the metal-supported catalysts containing carbon supports in Examples C1 to C7, reaching 1.0 A / cm 2 The current density was equal to or higher than that of the metal-supported catalysts containing carbon supports in Examples C1 to C7.

[0245] That is, the metal-supported catalysts containing carbon supports in Examples C1 to C7 tended to show a decrease in catalytic activity when the amount of ionomer mixed with the metal-supported catalyst was reduced (i.e., when the I / C ratio was reduced).

[0246] In contrast, the metal-supported catalysts containing carbon supports in Examples 1 to 3 exhibited catalytic activity equal to or greater than the catalytic activity before the amount of ionomer was reduced, even when the amount of ionomer mixed with the metal-supported catalyst was reduced.

[0247] Thus, the metal-supported catalysts containing the carbon supports of Examples 1 to 3 effectively maintained their catalytic activity and exhibited a high level of catalytic activity even when the amount of ionomer mixed with the metal-supported catalyst was reduced.

[0248] Furthermore, as shown in FIG. 2A, the carbon supports of Examples 1 to 3 have a pore volume (#0-70 nm) ("(1) DFT pore volume (#0-70 nm)" in the figure) of 0.70 cm 3 / g or less, and the pore volume (#<5nm) ("(2) DFT pore volume (#<5nm)" in the figure) is 0.31 cm 3 / g or more.

[0249] In contrast, the carbon supports of Examples C2, C3, and C5 to C7 had larger pore volumes (#0-70 nm) than the carbon supports of Examples 1 to 3. The carbon supports of Examples C1 and C4 had smaller pore volumes (#<5 nm) than the carbon supports of Examples 1 to 3.

[0250] Thus, the carbon supports of Examples 1 to 3 had a unique pore structure with a relatively small pore volume (#0-70 nm) and a relatively large pore volume (#<5 nm).The differences in the properties of the carbon supports of Examples C1 to C7 and those of Examples 1 to 3 were thought to be due to differences in the manufacturing conditions of these carbon supports.

[0251] The carbon supports of Examples 1 to 3 had relatively small pore volumes (#5-70 nm), pore volumes (#2-10 nm), and pore volumes (#10-70 nm).The carbon supports of Examples 1 to 3 also had relatively large pore volumes (#<2 nm).

[0252] The carbon supports of Examples 1 to 3 had relatively large pore volume ratios (#5 / (0-70)) and pore volume ratios (#5 / (5-70)). The carbon supports of Examples 1 to 3 also had relatively small most frequent diameters.

[0253] The carbon supports of Examples 1 to 3 had a moderately large BET specific surface area and exhibited relatively small hysteresis (#0.8P / P0) and hysteresis (#0.8P / P0).

[0254] 2B, the carbon supports of Examples 1 to 3 had relatively small Raman D width at half maximum, Raman G width at half maximum, and Raman 2D width at half maximum. The carbon supports of Examples 1 to 3 also had relatively large D / G ratios and 2D / G ratios. The carbon supports of Examples 1 to 3 also had relatively large true densities and bulk densities. The carbon supports of Examples 1 to 3 also had relatively large oxygen contents and nitrogen contents.

Claims

1. A carbon support for supporting catalytic metal particles, The volume of pores having a diameter of more than 0 nm and not more than 70 nm obtained by the DFT method from a nitrogen adsorption isotherm at a temperature of 77 K is 0.70 cm ３ / g or less, The volume of pores within a pore diameter range of less than 5 nm obtained from the nitrogen adsorption isotherm by the DFT method is 0.31 cm ３ / g or more, The true density obtained by the constant volume expansion method is 1.9 g / cm ３ That's all, In the Raman spectrum obtained by Raman spectroscopy, the Raman shift was 1340 cm －１ The half width at half maximum of the D band having a peak top in the vicinity is 50 cm －１ having a carbon structure showing: Carbon carrier.

2. The oxygen content obtained by elemental analysis is 0.5% by weight or more. The carbon support according to claim 1 .

3. The volume (cm) of pores having a pore diameter in the range of 5 nm or more and 70 nm or less obtained from the nitrogen adsorption isotherm by the DFT method ３ / g) to the volume (cm 3 ) of pores within the range of pore diameters of less than 5 nm ３ / g) is 9.0 or more; The carbon support according to claim 1 .

4. The volume of pores having a pore diameter of 5 nm or more and 70 nm or less, obtained from the nitrogen adsorption isotherm by the DFT method, is 1.00 cm ３ / g or less, The carbon support according to claim 1 .

5. The volume (cm) of the pores having a diameter of more than 0 nm and not more than 70 nm ３ / g) to the volume (cm 3 ) of pores within the range of pore diameters of less than 5 nm ３ / g) is 0.50 or more; The carbon support according to claim 1 .

6. In the log differential pore volume distribution obtained from the nitrogen adsorption isotherm by the DFT method, the most frequent diameter, which is the pore diameter giving the maximum value of the log differential pore volume within the pore diameter range of more than 0 nm and not more than 70 nm, is less than 9.0 nm; The carbon support according to claim 1 .

7. The specific surface area obtained from the nitrogen adsorption isotherm by the BET method is 500 m ２ / g or more, The carbon support according to claim 1 .

8. The specific surface area obtained from the nitrogen adsorption isotherm by the BET method is 2000 m ２ / g or less, The carbon support according to claim 1 .

9. In the Raman spectrum obtained by Raman spectroscopy, the Raman shift was 1580 cm －１ The half width at half maximum of the G band having a peak top in the vicinity is 60 cm －１ having a carbon structure showing: The carbon support according to claim 1 .

10. In the Raman spectrum obtained by Raman spectroscopy, the Raman shift was 2700 cm －１ The half width at half maximum of the 2D band having a peak top in the vicinity of 80 cm －１ having a carbon structure showing: The carbon support according to claim 1 .

11. In the Raman spectrum obtained by Raman spectroscopy, the Raman shift was 1580 cm －１ Raman shift of the G band intensity with a peak top near 1340 cm －１ The carbon structure has a D / G ratio, which is the ratio of the intensities of D bands having peak tops around 1.3 or more. The carbon support according to claim 1 .

12. In the Raman spectrum obtained by Raman spectroscopy, the Raman shift was 1580 cm －１ Raman shift of the G band intensity with a peak top near 2700 cm －１ The carbon structure has a 2D / G ratio, which is the ratio of the intensities of 2D bands having peak tops around 0.2 or more. The carbon support according to claim 1 .

13. The nitrogen content obtained by elemental analysis is 0.2% by weight or more. The carbon support according to claim 1 .

14. A carbon support according to any one of claims 1 to 13; catalytic metal particles supported on the carbon support; A metal supported catalyst comprising:

15. The catalyst comprises the metal supported catalyst of claim 14. electrode.

16. 16. The electrode of claim 15, battery.

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