The scale of time is important in chemistry. A typical catalytic reaction has turnover frequencies ranging from 0.01 to 10 or even 103 s-1. A complete turnover usually contains adsorption of reaction molecules, surface migration and several steps of elementary reaction, and finally the desorption of the product. Among which, the…
Recent developments in synchrotron radiation facilities and X-ray optics have further expanded the X-ray analytical toolbox for operando studies. These X-ray tools allow to follow the structure of the catalytic active site in action with high time-resolution and include X-ray absorption and emission spectroscopy, diffraction and total scattering. One of…
Liquid-phase transmission electron microscopy offers a unique combination of nanometer spatial resolution and millisecond temporal resolution. It has provided many useful insights into nanoscale reaction dynamics but achieving sub-nanometer resolution has proved difficult due to limitations in the current liquid cell designs. For this reason, atomic resolution TEM investigations of…
Organic Structure Directing Agents (OSDAs) play a central role in synthesis of zeolites. Typically, OSDAs consist in tetraalkylammonium cations that are trapped inside of the voids of zeolites. The positive charge of the occluded cations is compensated i) by the isomorphic substitution of Si atoms by trivalent atoms resulting in…
Directing groups have become pivotal in controlling the stereo- and regiochemistry of transition metal catalysed C–H activation and olefin difunctionalisation reactions. Regiocontrol in these reactions is generally achieved through formation of a stable, five-membered palladacycle. However, the less stable 6‑membered palladacycles can be accessed in Pd(II)-catalysed alkene functionalisation through the…
With the goal of identifying homogeneous catalysts with improved activity or selectivity, we exploit physical organic concepts, statistical learning techniques and optimization algorithms. We demonstrate how these approaches could be used independently or in tandem within automated workflows. We focus on both prototypical classes of reactions and challenging organic processes…
Mechanochemical synthesis allows in various cases the synthesis of materials which are otherwise difficult to access or complex to synthesize, such as rare earth metal hydrides, corundum with high surface areas, or supported metal catalysts. For such studies, milling vessels were equipped with various additional features, such as cryo-capabilities and…
Chemical transformations of alternative carbon-based materials, such as non-volatile biomass and waste plastic, are strongly influenced by the partitioning of reactants, intermediates, products, and spectator molecules (including the solvent) between the bulk liquid phase and the surfaces or pore spaces of solid catalysts. The relative affinities of the reacting molecules for…
We develop new porous materials based upon metal-organic frameworks and zeolites for applications in clean-air technology, catalysis, biomass conversion, separation and conductivity. Our key research interest is to investigate the host-guest binding underpinning their property and catalytic activity using state-of-the-art structural and dynamic studies by synchrotron X-ray diffraction, spectroscopy and…
