Wenqian Xu Seminar
Tuesday, October 8, 2019
12:00 pm - 2:00 pm
SERC Building, room 703
Title: Synchrotron X-ray Diffraction and Multimodal Methods for Materials Characterization
Speaker: Wenqian Xu, Department of Chemistry, Argonne National Laboratory, Lemont, IL
Understanding structure-property relationships is a main objective of materials research. Synchrotron powder X-ray diffraction (XRD) and pair distribution function (PDF) are great tools for this purpose, especially when used for in situ and operando measurements, where structures of functioning materials can be studied and directly correlated to their performance. The simple geometry and open space of synchrotron XRD and PDF instruments allow various customized sample environments as well as additional probes, such as IR and Raman, for multimodal research. This talk will present instrumentation and capabilities at high energy XRD and PDF beamlines at the Advanced Photon Source at Argonne National Lab, along with examples of research in catalysis and porous materials.
Wenqian Xu received his Ph.D. degree in Geosciences from Stony Brook University. He is interested in analyzing crystal structures of both minerals and synthetic materials and understanding how the structures are related to their properties. His research involves using in situ scattering and spectroscopic methods to study heterogeneous catalysts for chemical reactions related to hydrogen production, aiming at identifying active sites and species and elucidating reaction mechanisms. Wenqian is currently analyzing a group of Ni-based catalysts for ethanol steam reforming (ESR) reaction and attempting to improve activity and lifetime of the catalysts. A recent study on Ni/CeO2 catalyst revealed the how Ni metal and the ceria support interact in converting intermediate species involved in ESR. He is also working on synthesis of molybdenum carbide catalysts for carbon dioxide hydrogenation. He frequently use X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) in my research.