Metal-organic frameworks and porosity

Question 1

What are MOFs?

Answer 1

MOF = metal organic framework. Type of 3D metal structure linked by organic ligands to give large pores able to store guests. Generally low density materials as a result of void space.

Question 2

Why are MOFs important research materials?

Answer 2

MOFs thought to be useful in target of hydrogen storage, and other gaseous storage.

Question 3

What are the problems with H2 storage?

Answer 3

Storing hydrogen difficult as gaseous and light. High pressure required to have enough, but this is dangerous. H2 very hard to stick to as very small molecule.

Question 4

How can MOFs be used in CO2 capture?

Answer 4

MOFs can have amine guests, which are good at absorbing CO2 as can form amidic bonds and have electrostatic interactions between species to stabilise. Sudden jump in CO2 absorption seen over increasing pressure and decreasing temperature due to cooperative hydrogen-bonding effect.

Question 5

How can MOFs be used in water harvesting?

Answer 5

Water harvesting - suck water vapour out of the air in countries with limited water supply and release it as pure liquid water for drinking.
MOF-303: aluminium based (cheap) and able to cycle through filled and empty pores in minutes.