A similar theme, just read on revolution green site: cavities enhance reactions
It's time to properly model cavities!
Nature as a model
Nature provided the reference for the development of the new process. In biological systems, enzymes with small pockets in their surface accelerate chemical processes.
“We thought about how we could apply theses biological functions to organic chemistry,” explains Lercher. “While searching for suitable catalysts that accelerate the reaction, we stumbled upon zeolites – crystals with small cavities in which the reactions take place under cramped conditions comparable to those in enzyme pockets.”
Cornered hydronium ions
But, do cramped quarters really increase the reactivity? To answer this question, Lercher’s team compared the reactions of carbon compounds with acids in a beaker to the same reactions in zeolites. The result: In the crystal cavities, where the reacting molecules, for example alcohols, meet upon the hydronium ions of the acids, reactions run up to 100 times faster and at temperatures just over 100 °C.
“Our experiments demonstrate that zeolites as catalysts are similarly effective as enzymes: Both significantly reduce the energy levels required by the reactions,” reports Lercher. “The smaller the cavity, the larger the catalytic effect. We achieved the best results with diameters far below one nanometer.”