Zeolites are a unique class of crystalline aluminosilicates used on massive scales as sorbents, ion exchangers, molecular sieves, and catalysts. In catalytic reactions, such as cracking and isomerization, zeolites are renowned, yielding exceptional product slates based on a unique shape-selectivity. Strikingly, this unique performance is combined to a cheap, green, and low-complex synthesis.
The advantageous attributes of zeolites are derived from a large network of micropores in the size range of individual molecules (0.3-0.8 nm). Unfortunately though, reactant and product molecules barely fit in these micropores, and are forced to navigate the zeolite crystal at a snails’ pace in a kind of molecular traffic jam. As a result only a minor fraction of the zeolites active volume is used in catalysis.
Mesoporous zeolites couple a secondary network of large mesopores (size range 2-20 nm) to the micropores, to enhance the accessibility and thereby catalytic effectivity of the actives sites in the zeolite crystal. On an academic scale, accessible mesoporous zeolites have achieved superior catalytic performance in virtually any catalytic conversion: from the cracking of oil residues, to the production of aromatics, to the conversion of waste plastics, to the conversion of biomass streams, and many others.