Catalysis

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Slide 1

Catalysis

Catalyst: A substance that speeds up a reaction without being consumed

Enzyme: A large molecule (usually a protein) that catalyzes biological reactions.

Homogeneous catalyst: Present in the same phase as the reacting molecules.

Heterogeneous catalyst: Present in a different phase than the reacting molecules.

Slide 2

Lowering of Activation Energy by a Catalyst

Slide 3

Catalysts Increase the Number of Effective Collisions

Slide 4

Heterogeneous Catalysis

Step #1: Adsorption and activation of the reactants.

Carbon monoxide and nitrogen monoxide adsorbed on a platinum surface

Slide 5

Heterogeneous Catalysis

Step #2:

Migration of the adsorbed reactants on the surface.

Carbon monoxide and nitrogen monoxide arranged prior to reacting

Slide 6

Heterogeneous Catalysis

Step #3:

Reaction of the adsorbed substances.

Carbon dioxide and nitrogen form from previous molecules

Slide 7

Heterogeneous Catalysis

Step #4:

Escape, or desorption, of the products.

Carbon dioxide and nitrogen gases escape (desorb) from the platinum surface