Predictive morphology, stoichiometry and structure of surface species in supported Ru nanoparticles under H-2 and CO atmospheres from combined experimental and DFT studies

We are also grateful to Frank Krumeich and Emma Oakton for electron microscopy images, obtained on the ScopeM platform and to Maxence Valla for assistance with the NMR experiments. In addition, we are thankful to GLANTREO Ltd (Ireland) especially Dr John Hanrahan for providing SiO2-spheres support. We acknowledge the support from the Swiss National Supercomputing Center for computational resources.; International audience; Further understanding of the chemisorption properties towards CO and H-2 on silica-supported Ru nanoparticles is crucial in order to rationalize their high activity towards methanation, Fischer Tropsch and Water Gas Shift reactions. Ru nanoparticles having the same chemisorption properties towards CO and H-2 were synthesized on different silica-based supports in order to combine various analytical techniques and obtain complimentary detailed information on their structure; while silica spheres were used in order to obtain high-resolution TEM images of the Ru nanoparticles, high surface area silica-based material (SBA) allowed CO chemisorption to be monitored by C-13 NMR spectroscopy. In addition, a model of the hcp-based Ru nanoparticles observed by HR-TEM was used to predict by ab initio calculations the CO and H-2 coverages on the Ru nanoparticle under different conditions of interest in catalysis. For both adsorbates we show and quantify how the adsorption properties of the nanoparticle differ from the commonly used slab models. For the case of CO we show how the top, bridge and hollow sites can be present on the Ru nanoparticle, providing a description at atomistic level in good agreement with the IR spectroscopy measurements.