Fuel Cell and Corrosion

A fuel cell can be thought of as an electrochemical cell that generates electrical energy from fuel through the use of an electrochemical reaction. These cells require a constant supply of fuel as well as the presence of an oxidizing agent in order to maintain the reactions that generate electricity (generally oxygen). As a result, until the supply of fuel and oxygen is interrupted, these cells will continue to generate electricity indefinitely.

Working of a fuel cell

It is possible to generate electricity from the reaction between hydrogen and oxygen by using a fuel cell, which is a device that converts hydrogen into electricity. A cell of this type was used in the Apollo space programme, and it served two distinct functions: it served as a source of fuel and as a source of drinking water at the same time.

A hydrogen and oxygen gas was transferred into a concentrated solution of sodium hydroxide by means of carbon electrodes in this fuel cell, which performed its work. The following is an example of how the cells’ response can be written:

Cathode Reaction:   O2 + 2H2O – 4e– + 4OH–

Anode Reaction:      2H2 + 4OH– – 4H2O + 4e– 

Net Cell Reaction:    2H2 + O2   – 2H2O + 4e– 

The reaction rate of this electrochemical response, on the other hand, is extremely slow. This problem can be resolved with the help of a catalyst such as platinum or palladium, among other things. Before being incorporated into the electrodes, the catalyst is finely divided in order to increase the effective surface area of the electrodes.

Types of fuel cells

1) The Polymer Electrolyte Membrane (PEM) Fuel Cell

•These cells, which are also known as proton exchange membrane fuel cells, are used to generate electricity (or PEMFCs).

The temperature range in which these cells operate is from 50°C to 100°C, depending on the model.

•The electrolyte used in PEMFCs is a polymer that has the ability to conduct protons.

•A typical PEM fuel cell is made up of bipolar plates, a catalyst, electrodes, and a polymer membrane, among other components.

2) Phosphoric Acid Fuel Cell

•The use of phosphoric acid as an electrolyte in these fuel cells is based on the channelling of H++.

•This type of cell operates at temperatures ranging from 150°C to 200°C during normal operation.

•Because of the non-conductive nature of phosphoric acid, electrons are forced to travel through an external circuit to reach the cathode in order to function.

3) Solid Acid Fuel Cell

•As the electrolyte in these fuel cells, a solid acid material is used as a catalyst.

•The molecular structures of these solid acids are ordered when they are heated to low temperatures.

•When temperatures are raised above a certain point, a phase transition can occur, resulting in a significant increase in conductivity.

Advantages of fuel cells

1) More Stable: The fuel cells are designed to ensure that the movement of different parts within and around the cell is kept to a minimum. Therefore, they are more dependable and convenient than a standard cell phone.

2) The process of separating atoms and producing energy in fuel cells is extremely clean and ergonomic, which helps to conserve natural resources. As a result, it is beneficial to natural resources.

3) Fuel cells are by far the most ergonomic solution when combined with other technologies, and this is provided free of charge. You have the ability to design your own combination of turbines and solar panels. As a result, it has been established as complementary.

4) Fuel cells are scalable, meaning they can generate electricity in quantities ranging from a few mill watts to several megawatts. It also contributes to the powering of a variety of appliances, including mobile phones and homes. As a result, they are easily scaled.

Microbial fuel cell

Microbial fuel cell (also known as MFC) is a type of bioelectrochemical fuel cell system that generates electric current by diverting electrons produced by the microbiological oxidation of reduced compounds (also known as fuel or electron donor) on the anode to high-energy oxidized compounds such as oxygen (also known as oxidizing agent or electron acceptor) on the cathode through an external electrical circuit. MFCs can be divided into two general categories: those that are mediated and those that are unmediated. 

Corrosion

Corrosion is defined as the process of rusting away.A natural process that causes the transformation of pure metals into undesirable substances when they react with other substances such as water or air, according to the definition of corrosion, is described as follows: When metal comes into contact with the environment, this reaction causes damage or disintegration, which spreads over time to the entire bulk of the metal and eventually causes it to fail.

Example of Corrosion

When iron ore comes into contact with oxygen present in moist air, a brown coat is formed on top of it as a result of the formation of carbon dioxide. When iron ore comes into contact with oxygen present in moist air, a brown coat is formed on top of it. The rusting of iron is the term used to describe this process.

Corrosion can be avoided by following these steps:

The corrosion prevention points listed below demonstrate how corrosion can be avoided in a number of different ways.

Galvanization

A thin layer of zinc is applied to the surface of the iron during this process. It is usually accomplished by dipping an iron rod in molten zinc (see illustration). The inner part of the iron is protected from corrosion by a zinc layer applied on top of it.

Repainting and lubricating

The application of a layer of grease or paint to a metal surface can help to prevent the metal from being exposed to the external environment, thereby preventing corrosion.

CONCLUSION

A fuel cell can be thought of as an electrochemical cell that generates electrical energy from fuel through the use of an electrochemical reaction. These cells require a constant supply of fuel as well as the presence of an oxidizing agent in order to maintain the reactions that generate electricity (generally oxygen). Types of fuel cells are –

(1)PEM Fuel Cell

 (2)Phosphoric Acid Fuel Cell

 (3)Solid Acid Fuel Cell.

The fuel cells are designed to ensure that the movement of different parts within and around the cell is kept to a minimum. Therefore, they are more dependable and convenient than a standard cell phone.Corrosion is defined as the process of rusting away.A natural process that causes the transformation of pure metals into undesirable substances when they react with other substances such as water or air.