**X-Ray Spectroscopy — The Driving Force to Understand and Develop Catalysis**

Jakub Szlachetko and Jacinto Sá

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/61940

## **Abstract**

Catalysis is involved in about 90% of manmade chemicals. The development of novel or improved catalysts requires fundamental understanding of the commanding steps of a catalytic reaction. In simple terms, a catalytic transformation depends on the coupling be‐ tween catalyst electronic structure and reagents' molecular orbitals. Herein, we report a spectroscopic technique capable of determining the electronic structure of metal contain‐ ing catalysts under working conditions. The technique is called photon-in photon-out Xray spectroscopy and can be employed to characterize materials, unveil substrate adsorption parameters, and follow changes in electronic structure during catalytic reac‐ tions.

**Keywords:** Photon-in photon-out X-ray spectroscopy, Electronic structure, Spectroscopy under working conditions
