Combined X-ray Diffraction and Absorption Spectroscopy in Catalysis Research: Techniques and Applications

Among synchrotron-based techniques, X-ray absorption fine-structure spectroscopy (XAFS) and X-ray diffraction (XRD) are perhaps the ones most commonly used for in-situ and in-operando research. This chapter introduces the instrumentation used at the Daresbury, DORIS, European Synchrotron Radiation Facility (ESRF) and National Synchrotron Light Source (NSLS) for XRD and XAFS measurements and demonstrates its applicability for in-situ studies of catalytic reactions. Examples of combined XRD/XAFS that demonstrate the usefulness of the nearly simultaneous measurement are presented and discussed. These examples emphasize the complementary qualities of each technique by pointing out what information revealed by one technique is not accessible by the other. These complementary qualities are exploited to advance our understanding of the actual structure, which combines local and average information of the catalytic systems.