Luokat: Kaikki - types - application - regeneration

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Sample Mind Map

Catalysts play a crucial role in altering reaction rates by providing alternative pathways and emerging unchanged from the process. The deactivation of catalysts can occur through various mechanisms such as sintering, poisoning, and fouling.

Sample Mind Map

CATALYST

CATALYST REGENERATION

Homogenuos catalytic
Heterogenuos catalytic

REQUIREMENT FOR A GOOD CATALYST

A large interfacial area
The area of catalyst is provided by inner porous structure
A typical sillica
High surface area

TYPES/CLASSIFICATION CATALYST

Unsupported
Distinguish from supported catalyst

Example:The platinum gauze for ammonia oxidation

Supported
A catalyst consist of minute particles of an active material dispersed over a less active substance

Example:The packed- bed catalytic converted automobile

Monolithic
A catalyst that can be either porous or on- porous

Example:The platinum gauze reactor used in the ammonia oxidation portion of nitric acid manufacture

Molecular sieve
A catalyst that admit molecules but prevent large ones from entering

Example:The production of xylene from toluene and methane

Porous
A Catalyst that has a large area resulting from porous

Example:Raney nickel used in the hydrogenation of vegetable and animals oils

CATALYST DEACTIVATION

Poisoning
This mechanism occurs when the poisoning molecules become irreversibly chemisorbed to active sites, thereby reducing the number of sites available for the main reaction
Fouling or coking
This mechanism is common to reactions involving hydrocarbons
Aging phenomenon
Also known as sintering which referred to the loss of catalytic activity due to the loss of active surface area resulting from the prolonged exposure to high gas – phase temperature

APPLICATION OF CATALYST

Industrial gas companies
Power station
Oil rigs

CATALYST VS CATALYSIS

CATALYSIS
The development and use of catalyst is a major part of the constant search for new ways of increasing product yield and selectivity from chemical reactions
The occurrence, study and use of catalyst and catalytic processes
Catalyst changes a reaction rate by promoting a different molecular path (or mechanism) for the reaction
Defined as substance that affects the rate of a reaction but emerges from the process unchanged