The present invention provides a supported metal catalyst with excellent effectiveness factor of active metal particles which are also free from deactivation by contacting with ionomer.

According to the present invention, provided is a supported metal catalyst, comprising a support that is a collective body of conductive particles; and dispersed active metal particles supported on the conductive particles, wherein the conductive particles include a plurality of pores, an average entrance pore diameter of the pores is 1 to 20 nm, a standard deviation of the average entrance pore diameter is equal to or less than 50% of the average entrance pore diameter, a number fraction of the active metal particles supported in a surface layer region of the conductive particles divided by the total number of the active metal particles is equal to or more than 50%, and the surface layer region is a region on a surface of the conductive particles or a region in the pores within a depth of 15 nm from the surface.

The present invention provides a method for producing a nitrogen-doped highly graphitic porous carbon body, and a nitrogen-doped highly graphitic porous carbon body produced according to the same. Also, the present invention provides a method for producing a sulfur and nitrogen double-doped highly graphitic porous carbon body, a sulfur and nitrogen double-doped highly graphitic porous carbon body produced according to the same, and an electrode catalyst for a fuel cell and/or a water electrolysis reaction comprising the carbon body.

The present invention provides a method for producing a nitrogen-doped highly graphitic porous carbon body, and a nitrogen-doped highly graphitic porous carbon body produced according to the same. Also, the present invention provides a method for producing a sulfur and nitrogen double-doped highly graphitic porous carbon body, a sulfur and nitrogen double-doped highly graphitic porous carbon body produced according to the same, and an electrode catalyst for a fuel cell and/or a water electrolysis reaction comprising the carbon body.

Provided are an electrode catalyst production system and production method omitting transferring an electrode catalyst precursor, and shortening a drying time thereof. The system has an electrode catalyst precursor production device, a washing device and a drying device. The drying device includes executors for executing: an introduction step for introducing an electrode catalyst precursor into a container main body; a drying processing step for drying the precursor by heating and depressurizing the container main body, and stirring and mixing the precursor with a stirring blade; a cooling step for cooling the precursor by cooling and depressurizing the container main body, and stirring and mixing the precursor with the stirring blade; a slow oxidation step for performing a slow oxidation treatment on the precursor by supplying air to the container main body; and a retrieving step for retrieving the precursor inside the container main body.

A fuel cell catalyst including a conductive carrier and core-shell nanoparticles supported on the carrier. The core includes platinum and a transition metal and the shell includes a secondary metal. An electrochemical specific activity measured at a voltage of 0.05 V to 1.05 V (vs. RHE) in a potential range, at a scan rate of 5 mV/s and a rotation rate of 1,600 rpm in an O.sub.2-saturated 0.1 M HClO.sub.4 electrolyte solution is 0.3 mA/cm2 to 0.6 mA/cm2, and a mass activity is 0.05 mA/μg to 0.08 mA/μg.

The present invention provides an electrode catalyst which has excellent catalytic activity, and which can contribute to reducing the cost of a polymer electrolyte fuel cell (PEFC). According to the present invention, an electrode catalyst includes a hollow carrier including nanopores having a pore size of 1 to 20 nm, and a plurality of catalyst particles. The catalyst particles are supported both inside and outside the nanopores of the carrier, and comprise (zero-valent) Pt, and when a particle size distribution analysis of the catalyst particles is carried out using a three-dimensional reconstructed image obtained by electron beam tomography measurement employing STEM, the conditions of formula (S1): 100×(N10/N20)≤8.0 are satisfied (in the formula, N10 is the number of noble metal particles not in contact with a pore having a pore size of 1 nm or more, and N20 is the number of catalyst particles supported inside the nanopores of the carrier).

The present invention provides an electrode catalyst which has excellent catalytic activity, and which can contribute to reducing the cost of a polymer electrolyte fuel cell (PEFC). According to the present invention, an electrode catalyst includes a hollow carrier including nanopores having a pore size of 1 to 20 nm, and a plurality of catalyst particles. The catalyst particles are supported both inside and outside the nanopores of the carrier, and comprise (zero-valent) Pt, and when a particle size distribution analysis of the catalyst particles is carried out using a three-dimensional reconstructed image obtained by electron beam tomography measurement employing STEM, the conditions of formula (S1): 100×(N10/N20)≤8.0 are satisfied (in the formula, N10 is the number of noble metal particles not in contact with a pore having a pore size of 1 nm or more, and N20 is the number of catalyst particles supported inside the nanopores of the carrier).

In certain embodiments, an apparatus includes an electrolyte membrane layer (EML), and includes a first electrode catalyst layer (ECL) and a first metallic gas diffusion layer (MGDL) positioned to a first side of the EML such that the first ECL is positioned between the first MGDL and the EML. The first MGDL includes a metal-containing layer and a coating of porous material disposed on a surface of the metal-containing layer of the first MGDL that faces the first ECL. The apparatus further includes a second ECL and a second MGDL positioned to the second side of the EML such that the second ECL is positioned between the second MGDL and the EML. The second MGDL includes a metal-containing layer and a coating of porous material disposed on a surface of the metal-containing layer of the second MGDL that faces the second ECL.

Catalyst comprising a first layer having an outer layer with a layer comprising Pt directly thereon, wherein the first layer has an average thickness in a range from 0.04 to 30 nanometers, and wherein the layer. Catalysts described herein are useful, for example, in fuel cell membrane electrode assemblies.

Catalyst comprising a first layer having an outer layer with a layer comprising Pt directly thereon, wherein the first layer has an average thickness in a range from 0.04 to 30 nanometers, and wherein the layer. Catalysts described herein are useful, for example, in fuel cell membrane electrode assemblies.