Heterogeneous catalysis

Heterogeneous catalysis is a chemistry term which describes catalysis where the catalyst is in a different phase (ie. solid, liquid and gas) to the reactants.Heterogenous catalysts provide a surface for the chemical reaction to take place on.

Related Topics:
Chemistry - Catalysis - Catalyst - Solid - Liquid - Gas - Reactants

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

In order for the reaction to occur one or more of the reactants must diffuse to the catalyst surface and adsorb onto it. After reaction, the products must desorb from the surface and diffuse away from the solid surface. Frequently, this transport of reactants and products from one phase to another plays a dominant role in limiting the reaction rate. Understanding these transport phenomena and surface chemistry such as dispersion is an important area of heterogeneous catalyst research.

Related Topics:
Adsorb - Reaction rate - Surface chemistry - Dispersion

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The synthesis of ammonia is an example of heterogeneous catalysis:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

3H2(g) + N2(g) ↔ 2NH3(g) - catalysed by Fe(s).

~ ~ ~ ~ ~ ~ ~ ~ ~ ~