The Coordination of CuII in Zeolites − Structure and Spectroscopic Properties

Zeolites loaded with transition metal ions are promising heterogeneous catalysts. Knowledge about the location and structure of the metal centers is of paramount importance for the understanding of the catalytic potential of these materials. In this work, the spectroscopic studies of the coordination of CuII in zeolite A, ZK4, X, Y and mordenite are reviewed. Experimentally, diffuse reflectance spectroscopy (DRS) and electron spin resonance (ESR) spectroscopy have been applied to study the coordination of CuII in zeolites. Ab initio calculations on model clusters, representing the CuII sites in zeolites, are used for the interpretation of the experimental data. The combination of experimental spectroscopic information with theoretical results leads to a new and profound insight into the CuII−zeolite interaction.