Zeolites

 

"Nothing in life has to be feared, it is only to be understood.

Now is the time to understand more, so that we may fear less."

Marie Curie

May 8, 2023

Hi there, it's Giulia.

Today I wanted to discuss what an amazing first day we had at ITQ.

We discovered zeolites and how to synthesize them.

If you want to learn more about this amazing material and its uses this article is for you.

What are zeolites?

Did you know that the term zeolites comes from the Greek words "zeo", that means to boil, and "lithos", that means stone?

This explains well both the composition and the synthesis of this material.

In fact, they are formed by silicon, aluminium and oxygen. These elements link forming tetrahedra organised in a crystalline structure that looks like a net of pores and cavities.

You may think that this is just an artificial material. Actually zeolites were first discovered in nature and then chemists began to sinthesize them. Nowadays there are about 240 different zeolitic structures.

What are zeolites used for?

Zeolites have several applications in chemistry.

Their microporous structure acts as a molecular sieve that is used for the separation of molecules based on their size.

The channels and cavities of zeolites are very small (molecular dimensions) so they can be used efficiently as catalysts. These pores act as "containers" where reactions take place.

Furthermore, they can be modified for a specific reaction;

for example, if you need an acid catalyst, you can use a zeolite which has been subjected to an acid treatment.

Are they environmentally friendly?

Now, as I'm studying Green Chemistry I wanted to explore a little bit with you the sustainability of zeolites.

Let's take the previous example once again:

we are in need of an acid catalyst.

We have two options:

A) we can use a common acid, like sulphuric acid.

B) we can use our acid zeolites.

Which one is the most sustainable?

Short answer: B)

Sulphuric acid is used as omogeneous catalyst. This means that it is in the same physical state of the reaction mixture. At the end of the reaction the acid needs to be neutralized, a chemical process that forms inorganic salts that end up in the waste water and cause pollution. Furthermore, there are no chances of recycling the acid.

On the other hand, acid zeolites are efficient (some acid zeolites are stronger than sulphuric acid!), can be recycled after their use and they don't generate waste. 

In the Lab

If you want to know how to synthesize zeolites, watch the video below.

If you made it to this point of the article, don't forget to comment, like and share it.

Hope you enjoyed!😄😘

G.M.