In-Situ Dynamics and Reaction Kinetics in Nanoconfined Spaces

• Applicant: Dr. Muslim Dvoyashkin, Ph.D.
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2015 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 270592295

A major focus of modern catalysis research is placed on mass transfer limitations within micro- and mesoporous materials. Often, the rate of chemical reactions is limited by mass transfer within these nanoporous catalysts. Thus, an improved understanding of the transport mechanisms of molecular species confined to nanopores is an essential prerequisite in improving the efficiency of solid catalysts for numerous applications. In the proposed project, mass transfer processes in nanoscopic constraints of solid catalysts will be studied during chemical conversion using modern NMR techniques, including those with hyperpolarized probes. Moreover, the presence and formation of different phases within the pores during catalytic conversions, especially of higher molecular weight compounds, will be taken into consideration. These research questions will be studied for the acid or base catalyzed liquid-phase conversion of fats with alcohols, being important for biodiesel production, as an example. Corresponding nanoporous catalysts will be prepared and subsequently characterized. A variation of their catalytic properties, besides their pore geometry and size, will be achieved by hydrophililc/hydrophobic surface modification, and by incorporation of catalytically active components, such as e.g. earth alkali oxides. The combination of diffusion and hyperpolarized xenon NMR spectroscopies is planned to be applied to heterogeneously catalyzed reaction system under working conditions for the first time. From this, important insight into mass transport and phase behavior under the conditions of reaction within the nanoconfined spaces of the catalyst pores can be obtained. These insights will be related to and interpreted in view of the reaction kinetics as observed macroscopically from conventional catalytic experiments (in batch and continuous-flow conditions). This project will thus, improve our fundamental knowledge of the processes occurring under confinement inside porous catalysts via the application of modern NMR techniques.

• DFG Programme: Research Grants