0
The catalytic reaction that depends upon the structure of pores of the catalyst and the size of the reactant and product molecules is called shape/selective catalysis. Zeolites are good shape/selective catalysts because of their honeycomb-like structures. Zeolites are aluminosilicates i.e., three dimensional network silicates in which some silicon atoms are replaced by aluminium atoms. They are found in nature as well as synthesized for catalytic selectivity. Zeolites, before using as catalysts, are heated in vacuum so that the water of hydration is lost. As a result, zeolite becomes porous i.e., the cavities in the cage-like structure which were occupied by the water molecules become vacant. The size of the pores generally varies between 260 pm and 740 pm. Thus only those molecules can be adsorbed in these pores whose size is small enough to enter these cavities and also leave easily.
The reactions taking place in zeolites depend upon the size and shape of reactant and product molecules as well as upon the pores and cavities of the zeolites. That is why these types of reactions are called shape-selective catalysis reactions.
Zeolites are being very widely used as catalysts in petrochemical industries for cracking of hydrocarbons and isomerisation. An important zeolite catalyst used in the petroleum industry is ZSM-5. It converts alcohols directly into gasoline (petrol) by dehydrating them so that a mixture of hydrocarbons in formed.
Still curious? Ask our experts.
Chat with our AI personalities
Rene
Ross
MaxineAdd your answer:
Earn +20 pts
What is a 7 sided shape in Canada called?
it is called a seven sided shape in Canada
What is an 5 sided shape called?
An five sided shape is called a Pentagon
What is a 90 sided shape called?
A 90 sided shape is called Enneacontagon.
What is a 128 sided shape called?
A 128-sided shape is called a hecatoicosioctagon.
What is a 100 000 000 sided shape called?
A 1,000,000 shape is called a megagon
What has the author N Y Chen written?
N. Y. Chen has written: 'Shape selective catalysis in industrial applications' -- subject(s): Catalysis, Zeolites
What is the process called where humans can breed dogs to be the color size and shape that they want?
Selective Breeding
What is the definition of catalysis?
Catalysis is the action to increase the reaction rate of a chemical reaction using substances called catalysts which are not transformed during this reaction.
What is the process of changing reaction rates called?
The process of changing reaction rates is called catalysis. Catalysis involves the use of a substance (catalyst) to increase the rate of a chemical reaction without being consumed in the process.
When the active site undergoes a slight change in shape this is called?
Induced fit. This refers to the conformational changes that occur in the active site of an enzyme when a substrate binds, allowing for optimal interaction and catalysis to take place.
What is the part of the enzyme called that has a specific shape to fit with a specific substrate?
The part of the enzyme with a specific shape to bind with a specific substrate is called the active site. This is where the enzyme and substrate interact to form an enzyme-substrate complex, leading to catalysis of the reaction. The specificity of this interaction is crucial for the enzyme to carry out its biological function.
When was Catalysis Letters created?
Catalysis Letters was created in 1988.
When was Journal of Catalysis created?
Journal of Catalysis was created in 1962.
What has the author Sophia Berkman written?
Sophia Berkman has written: 'Catalysis, inorganic and organic' -- subject(s): Catalysis 'Catalysis'
What do you call the process of choosing parent organisms for the characteristics that you want in their offspring?
the process of selecting a few organisms with the desired traits to serve as parents of the next generation is called what?
What are some researchable topics in chemistry that focus on the keyword "catalysis"?
Some researchable topics in chemistry focusing on the keyword "catalysis" include: Enzyme catalysis in biological systems Heterogeneous catalysis in industrial processes Homogeneous catalysis in organic synthesis Photocatalysis for environmental applications Nanocatalysts for energy conversion processes
How do you use catalysis in a sentence?
One of the key technologies which is helping achieve these goals is heterogeneous catalysis.
