CHE 598 seminar by Dr. Jian Zhi Hu
About the event
“Development And Application Of In Situ High Resolution Magic Angle Spinning NMR Spectroscopy” presented by: Dr. Jian Zhi Hu
BIOGRAPHY:
Dr. Jian Zhi Hu received his BS in Physics in 1983 from Lanzhou University in China, MS in Applied Physics/NMR from Wuhan Institute of Physics, the Chinese Academy of Sciences in 1986, Ph.D. in Applied Physics/NMR in 1994 from a Joint-training program between Wuhan Institute of Physics and the Department of Chemistry, University of Utah.
Dr. Hu joined Pacific Northwest National Laboratory (PNNL) as a junior scientist in 2000 and is currently a senior scientist at PNNL. Dr. Hu is an author and co-author of more than 230 peer-reviewed publications. His h-Index is 45 with 11 issued US patents, two US R&D 100 awards and more than 7600 web of science citations. His major research focuses on new NMR capability development aimed at pushing the frontier of NMR and the applications of NMR to address critical problems in the fields of catalysis science, energy storage and biomedical science, etc. He pioneered the “Combined High Temperature and High Pressure MAS NMR” technique for in situ NMR investigations of reaction mechanism/dynamics, and a range of slow and ultra slow magic angle spinning, or magic angle turning (MAT) NMR techniques with sample spinning rate ranged from 1 to about 1000 Hz for enhanced spectral resolution in solids, semi-solids and biological materials. His current research interests and expertise include (i) in situ and ex situ NMR characterization of heterogeneous solid catalyst materials, surface functional groups and active cites, molecular dynamics at the interface, reaction mechanisms and pathways; (ii) in situ and ex situ studies of energy storage systems such as Li-ion and beyond Li-ion batteries; (iii) High field and high speed NMR spectroscopy, quantum chemistry calculations to predict molecular geometry and the principal values of chemical shift tensors, and quadrupolar coupling constants; (iv) NMR lineshape simulation, NMR pulse sequence design, programming, and testing; and (v) Developing magic angle spinning NMR metabolomics platform, in particular slow-MAS NMR metabolomics, for non-destructive investigations of dense biological cells (cells attached to solid surface) and intact biological tissues.
ABSTRACT:
High resolution magic angle spinning (MAS) NMR, a non-destructive and atomic specific tool, is a powerful technique for studying molecular structure and dynamics in a heterogeneous system containing a mixture of e.g., solid, semi-solid, liquid, and gaseous phases. Due to its intrinsic advantage of probing local environment, MAS NMR is an attractive tool for operando investigations of reaction kinetics and intermediates associated with material synthesis and chemical reactions using solid catalysts, and biological materials. However, the commercially available reusable-MAS rotors are rarely capable of achieving 100% seal while fast spinning even at ambient conditions. In particular, reusable sample cells that can efficiently perform at combined high temperature (> 100 °C) and high pressure (> 10 atm) conditions are not available previously in the field of MAS NMR due to technical complications associated with sealing heterogeneous samples at high temperature and pressure while spinning at a several kHz or more inside a strong magnetic field. In this seminar, I will discuss how we solved this problem by developing a perfectly sealed MAS NMR capability that is capable of sealing a heterogeneous sample containing solid, semi-solid, gases and liquids or a mixture of them under extreme experimental conditions of combined high pressure and high temperature. Examples of application in material synthesis and catalytic reactions, etc., will be given.