12. Catalysis and Catalytic Rate of Reaction

Question 1

Do catalysts effect equilibrium and rate?

Answer 1

Rate of reaction is affected, not equilibrium (since it only depends on temperature)

Question 2

What are the types of catalysts?

Answer 2

1) Homogeneous - single solution with at least one reactant
2) Heterogeneous - catalysts that involve more than one phase (more expensive)

Question 3

Why are porous catalysts typically used?

Answer 3

Having porous structures offer more surface area.

Question 4

Why are molecular sieves used?

Answer 4

-To prevent larger molecules from entering
-Selective…which control residence time of various molecules near the catalytically active surface

Question 5

When are monolithic catalysts used?

Answer 5

When the major considerations of a process is pressure drop and heat removal

Question 6

What are supported catalysts?

Answer 6

Catalysts that consist of minute active particles dispersed over a less active substance (which are the support)

Question 7

What are unsupported catalysts?

Answer 7

An unstructured catalyst that has active ingredients as the major part. Other substances are promoters which increase the activity

Question 8

Why don’t catalysts degrade?

Answer 8

-SIKE they do
-they degrade overtime maybe through change in surface crystal structure or poisoning (foreign material deposited on active portions of catalyst surface)

Question 9

What are isotherms?

Answer 9

Isoterm is the concentration of an adsorbed species as a function of pressure.

Question 10

What do isotherms portray?

Answer 10

Amount of a gas adsorbed on a solid at different pressures (but at one given temperature)