Abstract by Matthew Dickson
Chemistry and Biochemistry
Zeolites below 10 K: Exploring coordination chemistry through low-temperature heat capacity
Zeolites, a class of porous crystalline materials, are used widely for sorption and catalysis, but their thermodynamics are poorly understood. While working to fill this gap we found Schottky-like anomalies below 10 K in the heat capacity curves of some forms of zeolite A. We attribute these anomalies to Stark splitting of the magnetic moment of extra-framework cations, which reside in the zeolite structure and provide catalytic activity. We have developed a method to extract information about cation coordination environments from fits of the anomalies. With this method, a single heat capacity measurement not only reveals a zeolite’s thermodynamic stability, but also offers insight into cation coordination and therefore catalytic properties.