Zeolites are a diverse set of solid compounds made from silica (SiO4) and alumina (AlO4). These building blocks are organised in tetrahedral structures (a pyramid with a triangular base), with each aluminium or silicon connected to 4 oxygens. Zeolites have a wide range of uses such as catalysis (the speeding up of reactions such as catalytic cracking) and functioning as molecular sieves. The chemical feature that provides this diverse functionality is the regular gaps found in their structures. As can be seen from the video these gaps allow small molecules to enter and travel within them along channels. The channels can vary in diameter and dimensionality (1D, 2D or 3D) depending on the mix of alumina and silica that make up their structure. These channels give them a tremendous surface area that allows for small molecules to perform reactions within, similar to how an enzyme can catalyse the breakdown of biological material. Because of their porous structure, wide ranges of hydrocarbons can enter zeolite channels to undergo chemical reactions. Because zeolites are charged, they can exchange ions when put in water making them useful for water softening where calcium ions can be absorbed.
Zeolites are very stable compounds able to withstand high temperatures and high pressures as well as being resistant to water and air. These properties make them extremely attractive chemical compounds for use in industrial applications. Around 45 natural zeolites are known to exist, and over a hundred synthetic zeolites have been created, all with varying reactivities and channel sizes. The above video was developed using NarupaXR, a new virtual reality technology developed in Bristol that not only aids in the visualisation of these complex 3D structures, but that also allows for chemists to interact with the structure and substrate. This makes it easier to work out the likelihood of a compound being able to enter the structure and pass through to an active site and undergo a chemical change.