Abstract: A fuel cell electrode catalyst includes: catalyst metal particles containing at least one of platinum or a platinum alloy; and support particles supporting the catalyst metal particles. The crystallite size 2r obtained from an X-ray diffraction image of the catalyst metal particles is 3.8 nm or less, where r represents a crystallite radius of the catalyst metal particles obtained from the X-ray diffraction image. The amount of CO adsorption Y (mL/g-Pt) on the fuel cell electrode catalyst satisfies Y?40.386/r+1.7586.

Abstract: A fuel cell electrode catalyst includes catalyst metal particles and electrically conductive support particles supporting the catalyst metal particles. In the fuel cell electrode catalyst, a proportion of a surface area occupied by the catalyst metal particles with particle sizes of 4.5 nm or less to a surface area of the catalyst metal particles calculated from a transmission electron microscope image is 5% or less.

Abstract: A fuel cell electrode catalyst includes: catalyst metal particles containing at least one of platinum or a platinum alloy; and support particles supporting the catalyst metal particles. The crystallite size 2r obtained from an X-ray diffraction image of the catalyst metal particles is 3.8 nm or less, where r represents a crystallite radius of the catalyst metal particles obtained from the X-ray diffraction image. The amount of CO adsorption Y (mL/g?Pt) on the fuel cell electrode catalyst satisfies Y?40.386/r+1.7586.

Abstract: A fuel cell electrode catalyst includes catalyst metal particles and electrically conductive support particles supporting the catalyst metal particles. In the fuel cell electrode catalyst, a proportion of a surface area occupied by the catalyst metal particles with particle sizes of 4.5 nm or less to a surface area of the catalyst metal particles calculated from a transmission electron microscope image is 5% or less.

Abstract: An exhaust gas cleaning catalyst for inhibiting particulates grain growth includes composite metal particulates containing Pd and Rh, where the average proportion of the total Rh atoms relative to the total Pd and Rh atoms is 0.5 atom %, and given an X-ray wavelength of 1.5403 ?, when the diffraction surface in XRD analysis is the crystal lattice face of the Pd(111), and diffraction angles 2? indicating the diffraction peak positions on the diffraction surface are identified, the absolute value of the difference between the theoretical lattice constant B from a formula related to Vegard's law using the identified values, and the actual lattice constant C from a formula related to lattice constants and Bragg's law does not exceed 1.020×10?3 (?). A smaller absolute value of the difference between the theoretical and actual lattice constants is associated with a higher degree to which the Pd and Rh are combined with one another.

Abstract: A cell for electrochemical measurement is a cell for electrochemical measurement used for measurement by an electron beam that passes through an observation window, a MEMS chip for observation which includes a laminate including an electron-transmissive thin film and a substrate and in which a working electrode and a counter electrode are provided on a thin film and an MEMS chip for sealing which is a laminate including an electron-transmissive thin film and a substrate are disposed apart from each other, and there are areas in both laminates in which the substrates are not present, and an observation window including the thin film is formed in the areas, and the working electrode overlaps the observation window in both laminates and has a plurality of through-holes on an observation window in a direction in which an electron beam passes.

Abstract: A cell for electrochemical measurement is a cell for electrochemical measurement used for measurement by an electron beam that passes through an observation window, a MEMS chip for observation which includes a laminate including an electron-transmissive thin film and a substrate and in which a working electrode and a counter electrode are provided on a thin film and an MEMS chip for sealing which is a laminate including an electron-transmissive thin film and a substrate are disposed apart from each other, and there are areas in both laminates in which the substrates are not present, and an observation window including the thin film is formed in the areas, and the working electrode overlaps the observation window in both laminates and has a plurality of through-holes on an observation window in a direction in which an electron beam passes.

Abstract: A method of producing a displacement plating precursor, including a deposition step of depositing a Cu layer on a surface of a core particle formed of Pt or a Pt alloy by contacting a Cu ion-containing acidic aqueous solution with at least a portion of a Cu electrode, and contacting the Cu electrode with the core particle or with a composite, in which the core particle is supported on an electroconductive support, within the acidic aqueous solution or outside the acidic aqueous solution, and moreover contacting the core particle with the acidic aqueous solution under an inert gas atmosphere.

Abstract: A method of producing a displacement plating precursor, including a deposition step of depositing a Cu layer on a surface of a core particle formed of Pt or a Pt alloy by contacting a Cu ion-containing acidic aqueous solution with at least a portion of a Cu electrode, and contacting the Cu electrode with the core particle or with a composite, in which the core particle is supported on an electroconductive support, within the acidic aqueous solution or outside the acidic aqueous solution, and moreover contacting the core particle with the acidic aqueous solution under an inert gas atmosphere.