000K utf8 1100 $c2018 1500 eng 2050 urn:nbn:de:gbv:8-publ-22068 2051 10.1021/acs.jpclett.8b01782 3000 Schauermann, Swetlana 4000 Partial Hydrogenation of Unsaturated Carbonyl Compounds: Towards Ligand-Directed Heterogeneous Catalysis [Schauermann, Swetlana] 4209 In this perspective, we report on the recent progress in atomistic-level understanding of selective partial hydrogenation of α,β-unsaturated carbonyl compounds, particularly acrolein, towards unsaturated alcohols over model single crystalline and nanostructured Pd catalysts. This reaction was observed to proceed with nearly 100% selectivity over Pd(111) but not over supported Pd nanoparticles. The origin of the high selectivity was related to formation of a dense overlayer of oxopropyl surface species occurring at the early reaction stages via partial hydrogenation of the C=C bond in acrolein with only one H atom. This oxopropyl overlayer strongly modifies the adsorption and reactive properties of Pd(111) turning it 100% selective towards C=O bond hydrogenation. The underlying reaction mechanism represents a particular case of ligand-directed heterogeneous catalysis, in which the surface adsorbates do not directly participate in the catalytic process as the reaction intermediates but strongly affect the elementary reaction steps via specific adsorbate-adsorbate interactions. 4950 https://doi.org/10.1021/acs.jpclett.8b01782$xR$3Volltext$534 4950 https://nbn-resolving.org/urn:nbn:de:gbv:8-publ-22068$xR$3Volltext$534 4961 https://macau.uni-kiel.de/receive/publ_mods_00002206 5051 540 5550 acrolein partial hydrogenation 5550 Pd(111) 5550 Pd nanoparticles