Fuel cell in the context of Oxidizing agent

A radioisotope thermoelectric generator (RTG, RITEG), or radioisotope power system (RPS), is a type of nuclear battery that uses an array of thermocouples to convert the heat released by the decay of a suitable radioactive material into electricity by the Seebeck effect. This type of generator has no moving parts and is ideal for deployment in remote and harsh environments for extended periods with no risk of parts wearing out or malfunctioning.

RTGs are usually the most desirable power source for unmaintained situations that need a few hundred watts (or less) of power for durations too long for fuel cells, batteries, or generators to provide economically, and in places where solar cells are not practical. RTGs have been used as power sources in satellites, space probes, and uncrewed remote facilities such as a series of lighthouses built by the Soviet Union inside the Arctic Circle.

Surface science is the study of physical and chemical phenomena that occur at the interface of two phases, including solid–liquid interfaces, solid–gas interfaces, solid–vacuum interfaces, and liquid–gas interfaces. It includes the fields of surface chemistry and surface physics. Some related practical applications are classed as surface engineering. The science encompasses concepts such as heterogeneous catalysis, semiconductor device fabrication, fuel cells, self-assembled monolayers, and adhesives. Surface science is closely related to interface and colloid science. Interfacial chemistry and physics are common subjects for both. The methods are different. In addition, interface and colloid science studies macroscopic phenomena that occur in heterogeneous systems due to peculiarities of interfaces.

Palladium is a chemical element; it has the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1802 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas (formally 2 Pallas), which was thought to be a planet at the time, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form together a group of elements referred to as the platinum group metals. They have similar chemical properties, but palladium has the lowest melting point and is the least dense of them.

More than half the supply of palladium and its congener platinum is used in catalytic converters, which convert as much as 90% of the harmful gases in automobile exhaust (hydrocarbons, carbon monoxide, and nitrogen dioxide) into nontoxic substances (nitrogen, carbon dioxide and water vapor). Palladium is also used in electronics, dentistry, medicine, hydrogen purification, chemical applications, electrochemical sensors, electrosynthesis, groundwater treatment, and jewellery. Palladium is a key component of fuel cells, in which hydrogen and oxygen react to produce electricity, heat, and water.

A motor fuel is a fuel that is used to provide power to the engine (motor) of vehicles — typically a heat engine that produces thermal energy via oxidative combustion of liquid or gaseous fuel and then converts the heat into mechanical energy through reciprocating pistons or gas turbines.

Currently, the majority of motor vehicles, powerboats and light aircraft worldwide are propelled by internal combustion engines powered by petroleum-based hydrocarbon fossil fuels such as gasoline, diesel or autogas, while larger ships and aircraft use marine diesel oil and kerosene to power gas/steam turbine, turboprop and jet engines. Other fuel types include ethanol, biodiesel, biogasoline, propane, compressed natural gas (CNG) and hydrogen (either using fuel cells or hydrogen combustion). There are also cars that use a hybrid drivetrain of different power sources. The use of synthetic alternative fuels (especially renewable biofuels) is increasing, especially in Europe, as well as increasing mass adoption of battery electric vehicles (which are powered by battery-stored electricity instead of fuels).

Biogas is a gaseous renewable energy source produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste, wastewater, and food waste. Biogas is produced by anaerobic digestion with anaerobic organisms or methanogens inside an anaerobic digester, biodigester or a bioreactor. The gas composition is primarily methane (CH
₄) and carbon dioxide (CO
₂) and may have small amounts of hydrogen sulfide (H
₂S), moisture and siloxanes. The methane can be combusted or oxidized with oxygen. This energy release allows biogas to be used as a fuel; it can be used in fuel cells and for heating purposes, such as in cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat.

Biogas can be upgraded to natural gas quality specifications by stripping carbon dioxide and other contaminants. Biogas that has been upgraded to interchangeability with natural gas is called Renewable Natural Gas (RNG). RNG can be used a drop-in fuel in the gas grid or to produce compressed natural gas as a vehicle fuel.

Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference and identifiable chemical change. These reactions involve electrons moving via an electronically conducting phase (typically an external electric circuit, but not necessarily, as in electroless plating) between electrodes separated by an ionically conducting and electronically insulating electrolyte (or ionic species in a solution).

When a chemical reaction is driven by an electrical potential difference, as in electrolysis, or if a potential difference results from a chemical reaction as in an electric battery or fuel cell, it is called an electrochemical reaction. In electrochemical reactions, unlike in other chemical reactions, electrons are not transferred directly between atoms, ions, or molecules, but via the aforementioned electric circuit. This phenomenon is what distinguishes an electrochemical reaction from a conventional chemical reaction.

A power supply is an electrical device that supplies electric power to an electrical load. The main purpose of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load. As a result, power supplies are sometimes referred to as electric power converters. Some power supplies are separate standalone pieces of equipment, while others are built into the load appliances that they power. Examples of the latter include power supplies found in desktop computers and consumer electronics devices. Other functions that power supplies may perform include limiting the current drawn by the load to safe levels, shutting off the current in the event of an electrical fault, power conditioning to prevent electronic noise or voltage surges on the input from reaching the load, power-factor correction, and storing energy so it can continue to power the load in the event of a temporary interruption in the source power (uninterruptible power supply).

All power supplies have a power input connection, which receives energy in the form of electric current from a source, and one or more power output or power rail connections that deliver current to the load. The source power may come from the electric power grid, such as an electrical outlet, energy storage devices such as batteries or fuel cells, generators or alternators, solar power converters, or another power supply. The input and output are usually hardwired circuit connections, though some power supplies employ wireless energy transfer to power their loads without wired connections. Some power supplies have other types of inputs and outputs as well, for functions such as external monitoring and control.

Ionic conductivity (denoted by λ) is the movement of ions through a solid material, a phenomenon central to solid-state ionics. It is denoted by λ and measured in siemens per meter (S/m). While perfect crystals of inorganic compounds are typically electrical insulators, ionic conduction arises when defects are introduced—either intrinsically through thermal activation or extrinsically via doping with aliovalent impurities. These defects enable ion migration by providing pathways through the crystal lattice. Solid ionic conductors, known as solid electrolytes, are critical components in technologies such as all-solid-state batteries, supercapacitors, fuel cells, and thin-film microelectronic devices. The ionic conductivity (σ) follows an Arrhenius-type relationship with temperature, governed by activation energy barriers influenced by crystal structure and defect chemistry. Ionic conduction is one mechanism of current.

Chemical reaction engineering (reaction engineering or reactor engineering) is a specialty in chemical engineering or industrial chemistry dealing with chemical reactors. Frequently the term relates specifically to catalytic reaction systems where either a homogeneous or heterogeneous catalyst is present in the reactor. Sometimes a reactor per se is not present by itself, but rather is integrated into a process, for example in reactive separations vessels, retorts, certain fuel cells, and photocatalytic surfaces. The issue of solvent effects on reaction kinetics is also considered as an integral part.

A nuclear submarine is a submarine powered by a nuclear reactor, but not necessarily nuclear-armed.

Nuclear submarines have considerable performance advantages over "conventional" (typically diesel-electric) submarines. Nuclear propulsion, being completely independent of air, frees the submarine from the need to surface frequently, as is necessary for conventional submarines. The large amount of power generated by a nuclear reactor allows nuclear submarines to operate at high speed for long periods, and the long interval between refuelings grants a virtually unlimited range, making the only limits on voyage times factors such as the need to restock food or other consumables. Thus nuclear propulsion solves the problem of limited mission duration that all electric (battery or fuel cell powered) submarines face.

An electric car or electric vehicle (EV) is a passenger automobile that is propelled by an electric traction motor, using electrical energy as the primary source of propulsion. The term normally refers to a plug-in electric vehicle, typically a battery electric vehicle (BEV), which only uses energy stored in on-board battery packs, but broadly may also include plug-in hybrid electric vehicle (PHEV), range-extended electric vehicle (REEV) and fuel cell electric vehicle (FCEV), which can convert electric power from other fuels via a generator or a fuel cell.

Compared to conventional internal combustion engine (ICE) vehicles, electric cars are quieter, more responsive, have superior energy conversion efficiency and no exhaust emissions, as well as a typically lower overall carbon footprint from manufacturing to end of life (even when a fossil-fuel power plant supplying the electricity might add to its emissions). Due to the superior efficiency of electric motors, electric cars also generate less waste heat, thus reducing the need for engine cooling systems that are often large, complicated and maintenance-prone in ICE vehicles.

An emergency power system is an independent source of electrical power that supports important electrical systems on loss of normal power supply. A standby power system may include a standby generator, batteries and other apparatus. Emergency power systems are installed to protect life and property from the consequences of loss of primary electric power supply. It is a type of continual power system.

They find uses in a wide variety of settings from homes to hospitals, scientific laboratories, data centers, telecommunication equipment and ships. Emergency power systems can rely on generators, deep-cycle batteries, flywheel energy storage or fuel cells.

A battery electric vehicle (BEV), pure electric vehicle, only-electric vehicle, fully electric vehicle or all-electric vehicle is a type of electric vehicle (EV) that uses electrical energy exclusively from an on-board battery pack to power one or more electric traction motors, on which the vehicle solely relies for propulsion.

This definition excludes hybrid electric vehicles (HEVs; including mild, full and plug-in hybrids), which use internal combustion engines (ICEs) in adjunct to electric motors for propulsion; and fuel cell electric vehicles (FCEVs) and range-extended electric vehicles (REEVs), which consume fuel through a fuel cell or an ICE-driven generator to produce electricity needed for the electric motors. BEVs have no fuel tanks and replenish their energy storage by plugging into a charging station, electrical grid or getting a new battery at a battery swap station, and use motor controllers to modulate the output engine power and torque, thus eliminating the need for clutches, transmissions and sophisticated engine cooling as seen in conventional ICE vehicles. BEVs include – but are not limited to – all battery-driven electric cars, buses, trucks, forklifts, motorcycles and scooters, bicycles, skateboards, railcars, boat and personal watercraft, although in common usage the term usually refers specifically to passenger cars.

A hydrogen infrastructure is the infrastructure of points of hydrogen production, truck and pipeline transport, and hydrogen stations for the distribution and sale of hydrogen fuel, and thus a crucial prerequisite before a successful commercialization of fuel cell technology.

Hydrogen stations which are not situated near a hydrogen pipeline get supply via compressed hydrogen tube trailers, liquid hydrogen trailers, liquid hydrogen tank trucks or dedicated onsite production. Pipelines are the cheapest way to move hydrogen over long distances but must be designed to withstand the leakage and steel embrittlement caused by the hydrogen molecule. Hydrogen gas piping is routine in large oil-refineries, because hydrogen is used to hydrocrack fuels from crude oil. The IEA recommends existing industrial ports be used for production and natural gas pipelines for transport, international co-operation and shipping.