A fuel cell system includes a fuel cell stack, an anode tail gas oxidizer (ATO), an ATO injector configured to mix a first portion of an anode exhaust from the fuel cell stack with a cathode exhaust from the fuel cell stack and to provide a mixture of the first portion of the anode exhaust and the cathode exhaust into the ATO, an anode exhaust conduit which is configured to provide the first portion of the anode exhaust into the ATO injector, and cathode exhaust conduit which is configured to provide at least a portion of the cathode exhaust from the fuel cell stack into the ATO injector. The ATO injector includes injector tubes or injection apertures.

A fuel cell system includes a fuel cell stack, an anode tail gas oxidizer (ATO), an ATO injector configured to mix a first portion of an anode exhaust from the fuel cell stack with a cathode exhaust from the fuel cell stack and to provide a mixture of the first portion of the anode exhaust and the cathode exhaust into the ATO, an anode exhaust conduit which is configured to provide the first portion of the anode exhaust into the ATO injector, and cathode exhaust conduit which is configured to provide at least a portion of the cathode exhaust from the fuel cell stack into the ATO injector. The ATO injector includes injector tubes or injection apertures.

A method for forming a melamine-modified electrode that includes providing a metal based electrode and patterning a surface of the metal-based electrode by contacting the electrode with a melamine solution to form a patterned metal-based electrode. The patterned metal-based electrode includes metal sites blocked with melamine molecules and metal sites which are not blocked such that the metal-based electrode selectively adsorbs O.sub.2 instead of at least one of sulfate, phosphate, or sulphonate. A range of 20% to 40% of the metal sites are blocked with melamine molecules.

Disclosed is an antioxidant for a polymer electrolyte membrane of a fuel cell including cerium hydrogen phosphate (CeHPO.sub.4). The presence of cerium hydrogen phosphate in the antioxidant enhances the dissolution stability of cerium and improves the ability to capture water, leading to an increase in proton conductivity. In addition, the cerium hydrogen phosphate has a crystal structure composed of smaller cerium particles. This crystal structure greatly improves the ability of the antioxidant to prevent oxidation of the electrolyte membrane. Also disclosed are an electrolyte membrane including the antioxidant, a fuel cell including the electrolyte membrane, a method for preparing the antioxidant, a method for producing the electrolyte membrane, and a method for fabricating the fuel cell.

Provided are an electrode catalyst layer for a polymer electrolyte fuel cell, which is capable of improving drainage property and gas diffusion properties and capable of high output, and a polymer electrolyte fuel cell provided with the same. An electrode catalyst layer (2, 3) bonded to a polymer electrolyte membrane (1) includes a catalyst (13), carbon particles (14), a polymer electrolyte (15) and fibrous material (16), in which the electrode catalyst layer (2,3) has a density falling within a range of 500 mg/cm.sup.3 to 900 mg/cm.sup.3, or has a density falling within a range of 400 mg/cm.sup.3 to 1000 mg/cm.sup.3, and the mass of the polymer electrolyte (15) falls within a range of 10 mass % to 200 mass % with respect to the total mass of the carbon particles (14) and the fibrous material (16).

Provided are an electrode catalyst layer for a polymer electrolyte fuel cell, which is capable of improving drainage property and gas diffusion properties and capable of high output, and a polymer electrolyte fuel cell provided with the same. An electrode catalyst layer (2, 3) bonded to a polymer electrolyte membrane (1) includes a catalyst (13), carbon particles (14), a polymer electrolyte (15) and fibrous material (16), in which the electrode catalyst layer (2,3) has a density falling within a range of 500 mg/cm.sup.3 to 900 mg/cm.sup.3, or has a density falling within a range of 400 mg/cm.sup.3 to 1000 mg/cm.sup.3, and the mass of the polymer electrolyte (15) falls within a range of 10 mass % to 200 mass % with respect to the total mass of the carbon particles (14) and the fibrous material (16).

A porous body including a framework having a three-dimensional network structure, the framework having a body including nickel, cobalt, a first element and a second element as constituent elements, the cobalt having a proportion in mass of 0.2 or more and 0.8 or less relative to a total mass of the nickel and the cobalt, the first element including of at least one element selected from the group including of boron, iron and calcium, the second element including of at least one element selected from the group consisting of sodium, magnesium, aluminum, silicon, potassium, titanium, chromium, copper, zinc and tin, the first and second elements together having a proportion in mass of 5 ppm or more and 50,000 ppm or less in total relative to the body of the framework.

A polymer electrolyte membrane according to the present invention has a cluster diameter of 2.96 to 4.00 nm and a converted puncture strength of 300 gf/50 μm or more. The polymer electrolyte membrane according to the present invention has a low electric resistance and an excellent mechanical strength.

A metal-supported, planar cell arrangement (200) comprising at least one pair of cells (110a, 110b), each cell (110a, 110b) comprising a metal substrate (120a, 120b) having first and second sides and a porous region (124) providing fluid communication between the sides, planar cell chemistry layers (111, 112, 113) comprising fuel electrode, electrolyte, and air electrode layers being coated or deposited over, and supported by, the porous region (124) on the first side, wherein the metal substrates (120) are in a stacked arrangement with their cell chemistry layers (111, 112, 113) overlying each other such that either both their first sides, or, both their second sides face inwardly in a spaced, opposed relationship, the inwardly facing sides thereby defining a common first fluid volume (140) between them for one of fuel or oxidant.

A metal-supported, planar cell arrangement (200) comprising at least one pair of cells (110a, 110b), each cell (110a, 110b) comprising a metal substrate (120a, 120b) having first and second sides and a porous region (124) providing fluid communication between the sides, planar cell chemistry layers (111, 112, 113) comprising fuel electrode, electrolyte, and air electrode layers being coated or deposited over, and supported by, the porous region (124) on the first side, wherein the metal substrates (120) are in a stacked arrangement with their cell chemistry layers (111, 112, 113) overlying each other such that either both their first sides, or, both their second sides face inwardly in a spaced, opposed relationship, the inwardly facing sides thereby defining a common first fluid volume (140) between them for one of fuel or oxidant.