A New Type of Material for the Recovery of Hydrogen from Gas Mixtures

Molecular gas works: p‐tert‐Butylcalix[4]arene crystals possess large interstitial cavities when grown by sublimation and, although nonporous, are able to absorb and retain gases such as O2, N2, and CO2 under near‐ambient conditions. H2 is not retained and thus the material can be used to effect the separation of H2 from gas mixtures. The gas can be removed by evacuation or immersion of the crystals in nitrobenzene (see picture).