Speaker : Igor V.koptyug, Laboratory of Magnetic Resonance Microimaging, International Tomography Center SB RAS, Novosibirsk, Russia
Title : “Magnetic resonance imaging and spectroscopy in catalysis research with and without spin hyperpolarization”
Abstract: Versatile NMR-based techniques, including MRI, can provide diverse information on the structure of catalytically relevant materials and dynamic processes taking place within them. The most interesting and challenging among these are chemically reacting systems. In addition to visualization and quantification of composition of the fluid phase within the catalyst or reactor, the available information includes molecular diffusivities, velocities of flowing fluids and fluidized solids, local temperatures, adsorption of gases, and more. As NMR-based techniques are inherently spectroscopic, all this information can be obtained with chemical specificity, providing access to reaction conversion and selectivity. In addition, the imaging modality allows one to access all this useful information with spatial resolution. All this makes NMR-based techniques naturally applicable for operando studies of working catalysts and reactors. However, major challenges arise because NMR-based techniques are inferior to, e.g., optical spectroscopy in terms of detection sensitivity. To mitigate this issue, particularly when using low-field instruments, the hyperpolarization techniques can be potentially utilized in this context. In particular, the use of nuclear spin isomers of small symmetric molecules such as parahydrogen can be naturally suited for the MRI/MRS studies of industrially important reactions in model catalytic reactors. The relevant examples of the studies mentioned above will be presented and discussed.