sophiecarenco

We designed a low-temperature synthetic route for CeO₂ nanorods. We employed near-ambient-pressure X-ray photoelectron spectroscopy to monitor the cerium surface oxidation state during the initial annealing of the nanopowder, followed by exposure to a moderate pressure of H₂. We demonstrate that H₂ homolytic splitting at cerium sites is the main activation process at 100 °C, leading to the oxidation of 30% of the surface cerium atoms, while the H₂ splitting at oxygen sites was absent.

R. F. André, J.-J. Gallet, F. Bournel, S. Carenco, ChemCatChem 2024, DOI 10.1002/cctc.202400163.

We show that phosphines with adequate steric hindrance (e.g., PnBu₃ and PiBu₃) lower the onset temperature for phenylacetylene hydrogenation by nickel NPs under 7 bar of H₂, by ca 10 to 20 °C depending on the NP diameter. This result is of conceptual value because the hydrogenation may have been driven by the frustrated Lewis pair (FLP) between the Lewis basic phosphine and the Lewis acid nickel surface, forming a so-called “NanoFLP”. Moreover, we demonstrated that less than 2 phosphines per Ni surface atom are enough for the effect to arise. We showed that other terminal alkynes, like 1-octyne, can be hydrogenated with this method.

K. Azouzi, A. Ropp, S. Carenco, ACS Catalysis 2024, DOI 10.1021/acscatal.4c00054.