CN-121986392-A - Electrode catalyst

CN121986392ACN 121986392 ACN121986392 ACN 121986392ACN-121986392-A

Abstract

An electrode catalyst of the present disclosure includes a mesoporous material and particles of a catalyst metal supported at least inside the mesoporous material, the catalyst metal including platinum and including a metal different from the platinum, the mesoporous material having mesopores with a mode radius of 1nm or more and 25nm or less and a pore surface area of 1.0cm 3 /g or more and 3.0cm 3 /g or less, the catalyst metal being represented by the chemical formula Pt x Co 1－y Ni y , and the catalyst metal having x ranging from 1 to 3 and y ranging from 0.20 to 0.47 and L1 0 phases.

Inventors

NAKAO TAKUYA
MIYATA NOBUHIRO
KADOT TOMOYA
SHINTANI HARUHIKO
KUROHA TOMOHIRO

Assignees

松下知识产权经营株式会社

Dates

Publication Date: 20260505
Application Date: 20241216
Priority Date: 20240122

Claims (3)

1. An electrode catalyst comprising a mesoporous material and particles of a catalyst metal supported at least inside the mesoporous material, the catalyst metal comprising platinum and comprising a metal different from the platinum, The mesoporous material has mesopores with mode radius of 1nm to 25nm, and pore surface area of 1.0cm 3 /g to 3.0cm 3 /g, The catalyst metal is represented by the chemical formula Pt x Co 1－y Ni y , and x of the catalyst metal ranges from 1 to 3, and y ranges from 0.20 to 0.47, and the particles of the catalyst metal contain L1 0 phase.
2. The electrode catalyst according to claim 1, The mode radius of the mesopores of the mesoporous material is more than 3nm and less than 6 nm.
3. The electrode catalyst according to claim 1 or 2, The mesoporous material is mesoporous carbon.

Description

Electrode catalyst Technical Field The present disclosure relates to electrode catalysts. Background A Polymer Electrolyte Fuel Cell (PEFC) includes a membrane/electrode assembly for electrochemically reacting a fuel gas containing hydrogen and an oxidant gas containing oxygen (generating a power reaction). In general, an electrode catalyst layer constituting a membrane/electrode assembly is formed by preparing a catalyst paste obtained by dispersing an electrode catalyst and a polymer electrolyte (hereinafter referred to as an ionomer) having proton conductivity in a solvent such as water or alcohol, and coating the catalyst paste on a polymer electrolyte membrane or other base material and drying the same, wherein the electrode catalyst is formed by supporting a catalyst metal such as platinum on a catalyst support made of a conductive material such as carbon black. The microstructure of the electrode catalyst layer thus fabricated (hereinafter referred to as a three-phase interface structure) is a structure in which an ionomer is coated on the electrode catalyst. In this three-phase interface structure, it is considered that bringing the catalyst metal into contact with the ionomer improves the performance from the viewpoint of supplying protons to the surface of the catalyst metal. However, in recent years, it has been pointed out that the catalyst metal in contact with the ionomer is poisoned by the ionomer and the catalytic activity is lowered instead. In order to solve the problem of the decrease in activity of such an electrode catalyst, in order to suppress poisoning of catalyst metal by an ionomer, a method has been proposed in which catalyst metal particles are supported in a catalyst support such as mesoporous carbon, and the catalyst support on which the particles are supported is coated with an ionomer to form an electrode catalyst (for example, patent document 1). In addition, there is a report that the catalytic activity of the oxygen reduction reaction is improved by the regular (ordered) structuring of the catalyst metal. For example, patent document 1 reports that, when the catalyst metal is an alloy of platinum and cobalt, if an L1 0 phase, which is one of the regular structures of the catalyst metal, is formed, the catalytic activity of an electrode catalyst including the catalyst metal is improved. That is, in the case where the catalyst metal having the L1 0 phase is an alloy represented by the chemical formula "L1 0 -PtCo", the platinum atoms and the cobalt atoms are strongly bonded in the c-axis direction of the crystal, and the c-axis length becomes shorter than that of the irregular structure, so that a lattice distortion effect occurs, and the electron state of platinum changes, whereby the catalytic activity of the electrode catalyst is improved. Further, non-patent document 1 reports that the catalytic activity of an electrode catalyst provided with a catalyst metal represented by the chemical formula "L1 0 -PtNi" is improved by doping cobalt (Co) into such a catalyst metal. Prior art literature Patent literature Patent document 1 International publication No. 2022/196404 Non-patent literature Non-patent document 1:Advanced Energy Materials,9 (17), 1803771 (2019) Disclosure of Invention The object of the present disclosure is to provide an electrode catalyst capable of improving the catalytic activity of a catalyst metal supported inside a mesoporous material, as an example, as compared with the conventional electrode catalyst. In order to solve the above problems, an electrode catalyst according to one aspect (aspect) of the present disclosure includes a mesoporous material and particles of a catalyst metal supported at least inside the mesoporous material, the catalyst metal including platinum and including a metal different from the platinum, the mesoporous material having mesopores with a mode radius of 1nm to 25nm and a pore surface area of 1.0cm 3/g to 3.0cm 3/g, the catalyst metal being represented by a chemical formula Pt xCo1-yNiy, and x of the catalyst metal being in a range of 1 to 3 and y being in a range of 0.20 to 0.47, the particles of the catalyst metal including L1 0 phase. The electrode catalyst according to one embodiment of the present disclosure has an effect of being able to improve the catalytic activity of the catalyst metal supported inside the mesoporous material as compared with the conventional electrode catalyst. Drawings Fig. 1A is a schematic view of an L1 0 structure (binary system) in which catalyst metals (platinum and cobalt) are regularly arranged. Fig. 1B is a schematic view of an L1 0 structure (ternary system) in which catalyst metals (platinum, cobalt, and nickel) are regularly arranged. Fig. 2 is a diagram showing an example of an electrode catalyst according to an embodiment of the present disclosure. Fig. 3 is a diagram showing an example of X-ray diffraction (XRD) patterns of the electrode catalysts in experimental examples 1 to 10 an