A SOFC system includes: a fuel cell stack; a reformer; an air supplier: a combustor; and a controller. In a stop control of the above system, the controller calculates an average of ratios of the air to the raw material supplied to the reformer as a first average, in a case in which a molar fraction of a hydrogen component in the anode off-gas is higher than a molar fraction of a raw material component in the anode off-gas, and calculates the average of the ratios of the air to the raw material supplied to the reformer as a second average, in a case in which the molar fraction of the hydrogen component in the anode off-gas is lower than the molar fraction of the raw material component in the anode off-gas. The controller controls the air supplier so that the first average is higher than the second average.

A dual chamber solid oxide fuel cell integrated into the exhaust stream of an internal combustion engine, in which engine exhaust gases are routed to the anode of a tubular solid oxide fuel cell (SOFC) and heated secondary air is supplied to the cathode of the SOFC. The secondary air supply is heated using the existing engine temperature and exhaust gas temperature through a heat exchanger formed by a modified cylinder head and exhaust manifold. The dual chamber solid oxide fuel provides the necessary hydrocarbon and carbon monoxide scrubbing to achieve mandatory catalytic conversion for vehicle operation. In addition, the dual chamber solid oxide fuel cell is capable of generating sufficient electrical power for the vehicle. Omission of conventional catalytic convertors and alternators allows for improved efficiency and fuel economy of the internal combustion engine.

A dual chamber solid oxide fuel cell integrated into the exhaust stream of an internal combustion engine, in which engine exhaust gases are routed to the anode of a tubular solid oxide fuel cell (SOFC) and heated secondary air is supplied to the cathode of the SOFC. The secondary air supply is heated using the existing engine temperature and exhaust gas temperature through a heat exchanger formed by a modified cylinder head and exhaust manifold. The dual chamber solid oxide fuel provides the necessary hydrocarbon and carbon monoxide scrubbing to achieve mandatory catalytic conversion for vehicle operation. In addition, the dual chamber solid oxide fuel cell is capable of generating sufficient electrical power for the vehicle. Omission of conventional catalytic convertors and alternators allows for improved efficiency and fuel economy of the internal combustion engine.

The invention provides noble metal-free electro-catalyst compositions for use in acidic media, e.g., acidic electrolyte. The noble metal-free electro-catalyst compositions include non-noble metal absent of noble metal. The non-noble metal is non-noble metal oxide, and typically in the form of any configuration of a solid or hollow nano-material, e.g., nano-particles, a nanocrystalline thin film, nanorods, nanoshells, nanoflakes, nanotubes, nanoplates, nanospheres and nanowhiskers or combinations of myriad nanoscale architecture embodiments. Optionally, the noble metal-free electro-catalyst compositions include dopant, such as, but not limited to halogen. Acidic media includes oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells, and direct methanol fuel cells and oxygen evolution reaction (OER) in PEM-based water electrolysis and metal air batteries, and hydrogen generation from solar energy and electricity-driven water splitting.

The invention provides noble metal-free electro-catalyst compositions for use in acidic media, e.g., acidic electrolyte. The noble metal-free electro-catalyst compositions include non-noble metal absent of noble metal. The non-noble metal is non-noble metal oxide, and typically in the form of any configuration of a solid or hollow nano-material, e.g., nano-particles, a nanocrystalline thin film, nanorods, nanoshells, nanoflakes, nanotubes, nanoplates, nanospheres and nanowhiskers or combinations of myriad nanoscale architecture embodiments. Optionally, the noble metal-free electro-catalyst compositions include dopant, such as, but not limited to halogen. Acidic media includes oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells, and direct methanol fuel cells and oxygen evolution reaction (OER) in PEM-based water electrolysis and metal air batteries, and hydrogen generation from solar energy and electricity-driven water splitting.

Solid-state energy harvesters comprising layers of metal suboxides and cerium dioxide utilizing a solid-state electrolyte to produce power and methods of making and using the same are provided. The solid-state energy harvester may have two or three electrodes per cell and produces power in the presence of water vapor and oxygen.

Solid-state energy harvesters comprising layers of metal suboxides and cerium dioxide utilizing a solid-state electrolyte to produce power and methods of making and using the same are provided. The solid-state energy harvester may have two or three electrodes per cell and produces power in the presence of water vapor and oxygen.

The invention provides noble metal-free electro-catalyst compositions for use in acidic media, e.g., acidic electrolyte. The noble metal-free electro-catalyst compositions include non-noble metal absent of noble metal. The non-noble metal is non-noble metal oxide, and typically in the form of any configuration of a solid or hollow nano-material, e.g., nano-particles, a nanocrystalline thin film, nanorods, nanoshells, nanoflakes, nanotubes, nanoplates, nanospheres and nanowhiskers or combinations of myriad nanoscale architecture embodiments. Optionally, the noble metal-free electro-catalyst compositions include dopant, such as, but not limited to halogen. Acidic media includes oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells, and direct methanol fuel cells and oxygen evolution reaction (OER) in PEM-based water electrolysis and metal air batteries, and hydrogen generation from solar energy and electricity-driven water splitting.

The invention provides noble metal-free electro-catalyst compositions for use in acidic media, e.g., acidic electrolyte. The noble metal-free electro-catalyst compositions include non-noble metal absent of noble metal. The non-noble metal is non-noble metal oxide, and typically in the form of any configuration of a solid or hollow nano-material, e.g., nano-particles, a nanocrystalline thin film, nanorods, nanoshells, nanoflakes, nanotubes, nanoplates, nanospheres and nanowhiskers or combinations of myriad nanoscale architecture embodiments. Optionally, the noble metal-free electro-catalyst compositions include dopant, such as, but not limited to halogen. Acidic media includes oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells, and direct methanol fuel cells and oxygen evolution reaction (OER) in PEM-based water electrolysis and metal air batteries, and hydrogen generation from solar energy and electricity-driven water splitting.

A cathode having a tandem electrocatalyst structure is provided. The cathode includes a plurality of wires spaced apart from each other, a layer formed on a surface of each of the plurality of wires, and a plurality of nanoparticles disposed on the layer. Each of the plurality of wires includes a first perovskite material or a metal. The layer includes a second perovskite material. Each of the nanoparticles includes a metal oxide.