Jeroen A. van Bokhoven, Professor for Heterogeneous Catalysis Institute for Chemical and Bioengineering ETH Zurich Head of Laboratory for Catalysis and Sustainable Chemistry (LSK) Swiss Light Source Paul Scherrer Institute
Understanding a functioning catalyst requires understanding at the atomic scales in a time-resolved manner. X-rays can be readily used to accomplish that task, because of the large penetration depth of hard X-rays, in situ or operando experiments are possible. In addition, complementary techniques, such as the vibrational spectroscopies can be simultaneously applied. Recent development in instrumentation to perform quick EXAFS and secondary emission spectroscopy has provided exciting new opportunities to determine the changing electronic and geometric structures of a catalyst under reaction conditions. Examples of gas phase reactions are steam reforming and (preferential) oxidation of CO and an example of a liquid phase high pressure reaction is the selective hydrogenation of nitro benzenes. It will be highlighted how the structure of the catalyst adapts to the local environment, such as temperature, gas or liquid composition, and position within a catalytic reactor.
