Photo-Electrochemical Energy Conversion Device

The basic processes that occur in such a system are well understood. The semiconductor electrode efficiently absorbs light, producing an excited electronic state. In this excited state, the electron and the electron vacancy (the ‘‘hole’’) are both more energetic than they were in their respective ground states. The photo-excited electrons and holes are generally not tightly bound to an individual atom or set of atoms in the solid. (more…)

Artificial Photosynthetic Devices

Several molecular systems have been constructed that mimic various aspects of photosynthesis. Two of these utilize molecular systems that are derived from natural photosynthesis but that incorporate chemically based modifications to produce artificial photosynthetic devices. These devices use artificial photosynthetic pigments to drive chemical reactions across lipid bilayers or use noble metal catalysts to change the function of the photosynthetic process to produce hydrogen and oxygen instead of sugars ethanol and oxygen. Neither of these systems are sufficiently robust to be operated for extended periods of time as energy unit conversion devices, but they have shown that it is possible to produce artificial photosynthetic assemblies that function well in a laboratory setting. (more…)

Fuel Cell Applications as Battery Replacement

Fuel Cell Battery
A fuel cell is an electrochemical device that combines hydrogen with oxygen to generate electricity, heat and water to produce. In many ways, the fuel cell is similar to an electrochemical cell. Instead of a regular charge, a continuous supply of oxygen and hydrogen is supplied from outside. Oxygen is produced in the control of air and hydrogen as a fuel made from a pressure instrumentation container. Alternatively, methanol, propane, butane, natural gas supply and diesel are used. (more…)

Fuel Cell Applications for Transportation

Fuel Cell Transportation
Transport applications tend to demand rapid start-up and instant dynamic response from fuel cell systems, so a high-temperature fuel cell is unlikely to be competitive as the main engine in applications such as cars and buses. The prime candidate for these vehicle propulsion systems is the Polymer Electrolyte Fuel Cells, which exhibits both of the above characteristics while also having very high power density. This is important as it must also occupy a similar amount of space to an internal combustion engine. Of recent interest has been the development of auxiliary power units for vehicles, in which the fuel cell meets the onboard electric load of the vehicle. Both Polymer Electrolyte Fuel Cells and ITSOFCs are under development for this application. (more…)

Alkaline Fuel Cells - How It Works

Alkaline Fuel Cells
Alkaline fuel cell, often known as the Bacon fuel cell following the British inventor’ name. It has become the most created fuel cell systems and is the cell which traveled Man to the Moon. NASA has utilized alkaline fuel cells since beginning of-1960s, in Apollo-series tasks and on the Space Shuttle. The alkaline fuel cell has a long history in the space program. It is still used in the space shuttle in an expensive guise, producing power for the onboard systems by combining the pure hydrogen and oxygen stored in the rocket-fuelling system. (more…)

Polymer Electrolyte Membrane Fuel Cell Technologies

Fuel Cell Technologies
Fuel cells are typically classified according to type of electrolyte. While many varieties of fuel cells have been demonstrated in the laboratory, five major types are seeing development for commercial applications:

* Polymer electrolyte membrane (PEM) cells use a plastic (polymer) membrane that becomes electrically conducting when hydrated (saturated with water); they operate near 1001C.
* Alkaline fuel cells use a caustic electrolyte such as potassium hydroxide (KOH); they also operate near 1001C. (more…)

Polymer Electrolyte Fuel Cells - How It Works

Fuel Cells
Polymer Electrolyte Fuel Cells have high-power density, rapid startup, and low-temperature operation (around 80 to 120 C), and so are ideal for use in applications such as energy transport and battery replacement. The electrolyte used is a proton conducting polymer. This is typically a perfluorinated polymer, though other hydrocarbon-based membranes are under development in an attempt to reduce cost or to enable operation at temperatures approaching 200 C. The catalytically active layer sits adjacent to the membrane, supported on a PTFE treated carbon paper, which acts as current collector and gas diffusion layer. For operation on pure hydrogen, platinum is the most active catalyst, but alloys of platinum and ruthenium are used when higher levels of carbon monoxide are present (CO is a poison in all low temperature fuel cells). (more…)

What Is A Fuel Cell ?

The fuel cell can trace its roots back to the 1800s when a Welsh-born, Oxford-educated barrister, Sir William Robert Grove, realized that if electrolysis, using electricity, could split water into hydrogen and oxygen, then the opposite would also be true. Grove subsequently built a device that would combine hydrogen and oxygen to produce electricity—the world’s first gas battery, later renamed the fuel cell. (more…)

Fuel Cell Vehicles – How it Works?

Fuel Cell Vehicles
A fuel cell is an electrochemical device that directly converts a fuel to electricity by means of reactions on the surfaces of electrodes and transport of ions through an electrolyte. A fuel cell can be thought of as a chemical battery whose reactants are fed from external sources rather than packaged as part of the battery. A key feature of a fuel cell is transformation of the chemical potential energy of a fuel directly into electricity, a high-value form of energy that can be put to many uses from electricity conversion. The fuel cell’s direct energy unit conversion process occurs without an intermediate step of heat generation, as involved in combustion engines. (more…)

Fuel Cells And Fuel Processing with Proton Exchange Membrane


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Fuel cells are direct energy conversion devices that combine two reactants to produce electrical power. The reactants are typically a fuel such as hydrogen fuel cells, or methanol, and oxygen from the air. Fuel cells require an electrolyte capable of passing an ionic charge carrier across an electronic conduction barrier where the ions are driven by a concentration gradient. Fuel cells also need a catalytic-based anode and cathode for reactant preparation. For mesoscale/ microscale systems, fuel cells are best fabricated in thin film form. Depending on the desired power output of the system, the ‘‘footprint’’ may well be relatively large to supply the required power. (more…)

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