Catalysis

Catalysis

Catalysing for success This presentation will discuss what catalysts are, their mechanisms of action and their significance to the chemical industry.

Introduction Catalysis is a remarkable phenomenon. Quite apart from the scientific reality, the financial and environmental benefits of harnessing its power are very impressive.

Catalysts in definition developed by scientists in the last century, are materials that change the rate of attainment of equilibrium without themselves being changed or consumed in the process.

To illustrate the importance of catalysis, here are some of the many applications of it: Chemical and materials manufacturing, Fuel cells, Combustion devices, Pollution control systems, Laundry detergents.

The mechanisms of catalytic action in some of the above applications will be discussed later.

Types of Catalyst There are two types of catalyst: Industrial catalysts - These are non-biological catalysts, which include solid state, finely separated metals (particularly rare earth metals such as platinum, palladium, iridium etc) or one of many compounds known to possess catalytic activity.

Biological catalysts- These are complex proteins that possess catalytic activity. They are commonly referred to as enzymes. These are derived from living sources and will be discussed later.

Mechanisms of catalytic action in the Harber process? Catalysts work by changing the activation energy (Eact) for a reaction, i.e. the minimum energy needed for the reaction to occur. This is accomplished by providing a new mechanism or reaction path through which the reaction can proceed.

In the Harber Process, the catalyst comprised of finely divided iron. Reactant molecules of nitrogen and hydrogen are drawn to the metal surface by a process called adsorption.

Adsorption is the process of trapping gas and vapour molecules within the pores of a crystalline...