The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Swetlana Schauermann - One of the best experts on this subject based on the ideXlab platform.
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adsorption of Isophorone and trimethyl cyclohexanone on pd 111 a combination of infrared reflection absorption spectroscopy and density functional theory studies
Surface Science, 2016Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Swetlana Schauermann, Hansjoachim FreundAbstract:Abstract Understanding the interaction of α,β-unsaturated carbonyl compounds with late transition metals is a key prerequisite for rational design of new catalysts with desired selectivity towards C = C or C = O bond hydrogenation. The interaction of the α,β-unsaturated ketone Isophorone and the saturated ketone TMCH (3,3,5-trimethylcyclohexanone) with Pd(111) was investigated in this study as a prototypical system. Infrared reflection–absorption spectroscopy (IRAS) and density functional theory calculations including van der Waals interactions (DFT + vdW surf ) were combined to form detailed assignments of IR vibrational modes in the range from 3000 cm − 1 to 1000 cm − 1 in order to obtain information on the binding of Isophorone and TMCH to Pd(111) as well as to study the effect of co-adsorbed hydrogen. IRAS measurements were performed with deuterium-labeled ( d 5 -) Isophorone, in addition to unlabeled Isophorone and unlabeled TMCH. Experimentally observed IR absorption features and calculated vibrational frequencies indicate that Isophorone and TMCH molecules in multilayers have a mostly unperturbed structure with random orientation. At sub-monolayer coverages, strong perturbation and preferred orientations of the adsorbates were found. At low coverage, Isophorone interacts strongly with Pd(111) and adsorbs in a flat-lying geometry with the C = C and C = O bonds parallel, and a CH 3 group perpendicular, to the surface. At intermediate sub-monolayer coverage, the C = C bond is strongly tilted, while the C = O bond remains flat-lying, which indicates a prominent perturbation of the conjugated π system. Pre-adsorbed hydrogen leads to significant changes in the adsorption geometry of Isophorone, which suggests a weakening of its binding to Pd(111). At low coverage, the structure of the CH 3 groups seems to be mostly unperturbed on the hydrogen pre-covered surface. With increasing coverage, a conservation of the in-plane geometry of the conjugated π system was observed in the presence of hydrogen. In contrast to Isophorone, TMCH adsorbs in a strongly tilted geometry independent of the surface coverage. At low coverage, an adsorbate with a strongly distorted C = O bond is formed. With increasing exposure, species with a less perturbed C = O group appear.
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interaction of Isophorone with pd 111 a combination of infrared reflection absorption spectroscopy near edge x ray absorption fine structure and density functional theory studies
Journal of Physical Chemistry C, 2014Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Martin Oehzelt, Swetlana SchauermannAbstract:Atomistic level understanding of interaction of α,β-unsaturated carbonyls with late transition metals is a key prerequisite for rational design of new catalytic materials with the desired selectivity toward C═C or C═O bond hydrogenation. The interaction of this class of compounds with transition metals was investigated on α,β-unsaturated ketone Isophorone on Pd(111) as a prototypical system. In this study, infrared reflection–absorption spectroscopy (IRAS), near-edge X-ray absorption fine structure (NEXAFS) experiments, and density functional theory calculations including van der Waals interactions (DFT+vdW) were combined to obtain detailed information on the binding of Isophorone to palladium at different coverages and on the effect of preadsorbed hydrogen on the binding and adsorption geometry. According to these experimental observations and the results of theoretical calculations, Isophorone adsorbs on Pd(111) in a flat-lying geometry at low coverages. With increasing coverage, both C═C and C═O bonds ...
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interaction of Isophorone with pd 111 a combination of iras nexafs and dft studies
Journal of Physical Chemistry C, 2014Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Martin Oehzelt, Swetlana SchauermannAbstract:Atomistic level understanding of interaction of α,β-unsaturated carbonyls with late transition metals is a key prerequisite for rational design of new catalytic materials with the desired selectivity toward C=C or C=O bond hydrogenation. The interaction of this class of compounds with transition metals was investigated on α,β-unsaturated ketone Isophorone on Pd(111) as a prototypical system. In this study, infrared reflection-absorption spectroscopy (IRAS), near-edge x-ray absorption fine structure (NEXAFS) experiments and density functional theory calculations including van der Waals interactions (DFT+vdW) were combined to obtain detailed information on the binding of Isophorone to palladium at different coverages and on the effect of pre-adsorbed hydrogen on the binding and adsorption geometry. According to these experimental observations and the results of theoretical calculations, Isophorone adsorbs on Pd(111) in a flat-lying geometry at low coverages. With increasing coverage, both C=C and C=O bonds of Isophorone tilt with respect to the surface plane. The tilting is considerably more pronounced for the C=C bond on the pristine Pd(111) surface, indicating a prominent perturbation and structural distortion of the conjugated π system upon interaction with Pd. Pre-adsorbed hydrogen leads to higher tilting angles of both π bonds, which points to much weaker interaction of Isophorone with hydrogen pre-covered
Karlheinz Dostert - One of the best experts on this subject based on the ideXlab platform.
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adsorption of Isophorone and trimethyl cyclohexanone on pd 111 a combination of infrared reflection absorption spectroscopy and density functional theory studies
Surface Science, 2016Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Swetlana Schauermann, Hansjoachim FreundAbstract:Abstract Understanding the interaction of α,β-unsaturated carbonyl compounds with late transition metals is a key prerequisite for rational design of new catalysts with desired selectivity towards C = C or C = O bond hydrogenation. The interaction of the α,β-unsaturated ketone Isophorone and the saturated ketone TMCH (3,3,5-trimethylcyclohexanone) with Pd(111) was investigated in this study as a prototypical system. Infrared reflection–absorption spectroscopy (IRAS) and density functional theory calculations including van der Waals interactions (DFT + vdW surf ) were combined to form detailed assignments of IR vibrational modes in the range from 3000 cm − 1 to 1000 cm − 1 in order to obtain information on the binding of Isophorone and TMCH to Pd(111) as well as to study the effect of co-adsorbed hydrogen. IRAS measurements were performed with deuterium-labeled ( d 5 -) Isophorone, in addition to unlabeled Isophorone and unlabeled TMCH. Experimentally observed IR absorption features and calculated vibrational frequencies indicate that Isophorone and TMCH molecules in multilayers have a mostly unperturbed structure with random orientation. At sub-monolayer coverages, strong perturbation and preferred orientations of the adsorbates were found. At low coverage, Isophorone interacts strongly with Pd(111) and adsorbs in a flat-lying geometry with the C = C and C = O bonds parallel, and a CH 3 group perpendicular, to the surface. At intermediate sub-monolayer coverage, the C = C bond is strongly tilted, while the C = O bond remains flat-lying, which indicates a prominent perturbation of the conjugated π system. Pre-adsorbed hydrogen leads to significant changes in the adsorption geometry of Isophorone, which suggests a weakening of its binding to Pd(111). At low coverage, the structure of the CH 3 groups seems to be mostly unperturbed on the hydrogen pre-covered surface. With increasing coverage, a conservation of the in-plane geometry of the conjugated π system was observed in the presence of hydrogen. In contrast to Isophorone, TMCH adsorbs in a strongly tilted geometry independent of the surface coverage. At low coverage, an adsorbate with a strongly distorted C = O bond is formed. With increasing exposure, species with a less perturbed C = O group appear.
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interaction of Isophorone with pd 111 a combination of infrared reflection absorption spectroscopy near edge x ray absorption fine structure and density functional theory studies
Journal of Physical Chemistry C, 2014Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Martin Oehzelt, Swetlana SchauermannAbstract:Atomistic level understanding of interaction of α,β-unsaturated carbonyls with late transition metals is a key prerequisite for rational design of new catalytic materials with the desired selectivity toward C═C or C═O bond hydrogenation. The interaction of this class of compounds with transition metals was investigated on α,β-unsaturated ketone Isophorone on Pd(111) as a prototypical system. In this study, infrared reflection–absorption spectroscopy (IRAS), near-edge X-ray absorption fine structure (NEXAFS) experiments, and density functional theory calculations including van der Waals interactions (DFT+vdW) were combined to obtain detailed information on the binding of Isophorone to palladium at different coverages and on the effect of preadsorbed hydrogen on the binding and adsorption geometry. According to these experimental observations and the results of theoretical calculations, Isophorone adsorbs on Pd(111) in a flat-lying geometry at low coverages. With increasing coverage, both C═C and C═O bonds ...
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interaction of Isophorone with pd 111 a combination of iras nexafs and dft studies
Journal of Physical Chemistry C, 2014Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Martin Oehzelt, Swetlana SchauermannAbstract:Atomistic level understanding of interaction of α,β-unsaturated carbonyls with late transition metals is a key prerequisite for rational design of new catalytic materials with the desired selectivity toward C=C or C=O bond hydrogenation. The interaction of this class of compounds with transition metals was investigated on α,β-unsaturated ketone Isophorone on Pd(111) as a prototypical system. In this study, infrared reflection-absorption spectroscopy (IRAS), near-edge x-ray absorption fine structure (NEXAFS) experiments and density functional theory calculations including van der Waals interactions (DFT+vdW) were combined to obtain detailed information on the binding of Isophorone to palladium at different coverages and on the effect of pre-adsorbed hydrogen on the binding and adsorption geometry. According to these experimental observations and the results of theoretical calculations, Isophorone adsorbs on Pd(111) in a flat-lying geometry at low coverages. With increasing coverage, both C=C and C=O bonds of Isophorone tilt with respect to the surface plane. The tilting is considerably more pronounced for the C=C bond on the pristine Pd(111) surface, indicating a prominent perturbation and structural distortion of the conjugated π system upon interaction with Pd. Pre-adsorbed hydrogen leads to higher tilting angles of both π bonds, which points to much weaker interaction of Isophorone with hydrogen pre-covered
Alexandre Tkatchenko - One of the best experts on this subject based on the ideXlab platform.
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adsorption of Isophorone and trimethyl cyclohexanone on pd 111 a combination of infrared reflection absorption spectroscopy and density functional theory studies
Surface Science, 2016Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Swetlana Schauermann, Hansjoachim FreundAbstract:Abstract Understanding the interaction of α,β-unsaturated carbonyl compounds with late transition metals is a key prerequisite for rational design of new catalysts with desired selectivity towards C = C or C = O bond hydrogenation. The interaction of the α,β-unsaturated ketone Isophorone and the saturated ketone TMCH (3,3,5-trimethylcyclohexanone) with Pd(111) was investigated in this study as a prototypical system. Infrared reflection–absorption spectroscopy (IRAS) and density functional theory calculations including van der Waals interactions (DFT + vdW surf ) were combined to form detailed assignments of IR vibrational modes in the range from 3000 cm − 1 to 1000 cm − 1 in order to obtain information on the binding of Isophorone and TMCH to Pd(111) as well as to study the effect of co-adsorbed hydrogen. IRAS measurements were performed with deuterium-labeled ( d 5 -) Isophorone, in addition to unlabeled Isophorone and unlabeled TMCH. Experimentally observed IR absorption features and calculated vibrational frequencies indicate that Isophorone and TMCH molecules in multilayers have a mostly unperturbed structure with random orientation. At sub-monolayer coverages, strong perturbation and preferred orientations of the adsorbates were found. At low coverage, Isophorone interacts strongly with Pd(111) and adsorbs in a flat-lying geometry with the C = C and C = O bonds parallel, and a CH 3 group perpendicular, to the surface. At intermediate sub-monolayer coverage, the C = C bond is strongly tilted, while the C = O bond remains flat-lying, which indicates a prominent perturbation of the conjugated π system. Pre-adsorbed hydrogen leads to significant changes in the adsorption geometry of Isophorone, which suggests a weakening of its binding to Pd(111). At low coverage, the structure of the CH 3 groups seems to be mostly unperturbed on the hydrogen pre-covered surface. With increasing coverage, a conservation of the in-plane geometry of the conjugated π system was observed in the presence of hydrogen. In contrast to Isophorone, TMCH adsorbs in a strongly tilted geometry independent of the surface coverage. At low coverage, an adsorbate with a strongly distorted C = O bond is formed. With increasing exposure, species with a less perturbed C = O group appear.
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interaction of Isophorone with pd 111 a combination of infrared reflection absorption spectroscopy near edge x ray absorption fine structure and density functional theory studies
Journal of Physical Chemistry C, 2014Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Martin Oehzelt, Swetlana SchauermannAbstract:Atomistic level understanding of interaction of α,β-unsaturated carbonyls with late transition metals is a key prerequisite for rational design of new catalytic materials with the desired selectivity toward C═C or C═O bond hydrogenation. The interaction of this class of compounds with transition metals was investigated on α,β-unsaturated ketone Isophorone on Pd(111) as a prototypical system. In this study, infrared reflection–absorption spectroscopy (IRAS), near-edge X-ray absorption fine structure (NEXAFS) experiments, and density functional theory calculations including van der Waals interactions (DFT+vdW) were combined to obtain detailed information on the binding of Isophorone to palladium at different coverages and on the effect of preadsorbed hydrogen on the binding and adsorption geometry. According to these experimental observations and the results of theoretical calculations, Isophorone adsorbs on Pd(111) in a flat-lying geometry at low coverages. With increasing coverage, both C═C and C═O bonds ...
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interaction of Isophorone with pd 111 a combination of iras nexafs and dft studies
Journal of Physical Chemistry C, 2014Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Martin Oehzelt, Swetlana SchauermannAbstract:Atomistic level understanding of interaction of α,β-unsaturated carbonyls with late transition metals is a key prerequisite for rational design of new catalytic materials with the desired selectivity toward C=C or C=O bond hydrogenation. The interaction of this class of compounds with transition metals was investigated on α,β-unsaturated ketone Isophorone on Pd(111) as a prototypical system. In this study, infrared reflection-absorption spectroscopy (IRAS), near-edge x-ray absorption fine structure (NEXAFS) experiments and density functional theory calculations including van der Waals interactions (DFT+vdW) were combined to obtain detailed information on the binding of Isophorone to palladium at different coverages and on the effect of pre-adsorbed hydrogen on the binding and adsorption geometry. According to these experimental observations and the results of theoretical calculations, Isophorone adsorbs on Pd(111) in a flat-lying geometry at low coverages. With increasing coverage, both C=C and C=O bonds of Isophorone tilt with respect to the surface plane. The tilting is considerably more pronounced for the C=C bond on the pristine Pd(111) surface, indicating a prominent perturbation and structural distortion of the conjugated π system upon interaction with Pd. Pre-adsorbed hydrogen leads to higher tilting angles of both π bonds, which points to much weaker interaction of Isophorone with hydrogen pre-covered
Aditya Savara - One of the best experts on this subject based on the ideXlab platform.
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adsorption of Isophorone and trimethyl cyclohexanone on pd 111 a combination of infrared reflection absorption spectroscopy and density functional theory studies
Surface Science, 2016Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Swetlana Schauermann, Hansjoachim FreundAbstract:Abstract Understanding the interaction of α,β-unsaturated carbonyl compounds with late transition metals is a key prerequisite for rational design of new catalysts with desired selectivity towards C = C or C = O bond hydrogenation. The interaction of the α,β-unsaturated ketone Isophorone and the saturated ketone TMCH (3,3,5-trimethylcyclohexanone) with Pd(111) was investigated in this study as a prototypical system. Infrared reflection–absorption spectroscopy (IRAS) and density functional theory calculations including van der Waals interactions (DFT + vdW surf ) were combined to form detailed assignments of IR vibrational modes in the range from 3000 cm − 1 to 1000 cm − 1 in order to obtain information on the binding of Isophorone and TMCH to Pd(111) as well as to study the effect of co-adsorbed hydrogen. IRAS measurements were performed with deuterium-labeled ( d 5 -) Isophorone, in addition to unlabeled Isophorone and unlabeled TMCH. Experimentally observed IR absorption features and calculated vibrational frequencies indicate that Isophorone and TMCH molecules in multilayers have a mostly unperturbed structure with random orientation. At sub-monolayer coverages, strong perturbation and preferred orientations of the adsorbates were found. At low coverage, Isophorone interacts strongly with Pd(111) and adsorbs in a flat-lying geometry with the C = C and C = O bonds parallel, and a CH 3 group perpendicular, to the surface. At intermediate sub-monolayer coverage, the C = C bond is strongly tilted, while the C = O bond remains flat-lying, which indicates a prominent perturbation of the conjugated π system. Pre-adsorbed hydrogen leads to significant changes in the adsorption geometry of Isophorone, which suggests a weakening of its binding to Pd(111). At low coverage, the structure of the CH 3 groups seems to be mostly unperturbed on the hydrogen pre-covered surface. With increasing coverage, a conservation of the in-plane geometry of the conjugated π system was observed in the presence of hydrogen. In contrast to Isophorone, TMCH adsorbs in a strongly tilted geometry independent of the surface coverage. At low coverage, an adsorbate with a strongly distorted C = O bond is formed. With increasing exposure, species with a less perturbed C = O group appear.
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interaction of Isophorone with pd 111 a combination of infrared reflection absorption spectroscopy near edge x ray absorption fine structure and density functional theory studies
Journal of Physical Chemistry C, 2014Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Martin Oehzelt, Swetlana SchauermannAbstract:Atomistic level understanding of interaction of α,β-unsaturated carbonyls with late transition metals is a key prerequisite for rational design of new catalytic materials with the desired selectivity toward C═C or C═O bond hydrogenation. The interaction of this class of compounds with transition metals was investigated on α,β-unsaturated ketone Isophorone on Pd(111) as a prototypical system. In this study, infrared reflection–absorption spectroscopy (IRAS), near-edge X-ray absorption fine structure (NEXAFS) experiments, and density functional theory calculations including van der Waals interactions (DFT+vdW) were combined to obtain detailed information on the binding of Isophorone to palladium at different coverages and on the effect of preadsorbed hydrogen on the binding and adsorption geometry. According to these experimental observations and the results of theoretical calculations, Isophorone adsorbs on Pd(111) in a flat-lying geometry at low coverages. With increasing coverage, both C═C and C═O bonds ...
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interaction of Isophorone with pd 111 a combination of iras nexafs and dft studies
Journal of Physical Chemistry C, 2014Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Martin Oehzelt, Swetlana SchauermannAbstract:Atomistic level understanding of interaction of α,β-unsaturated carbonyls with late transition metals is a key prerequisite for rational design of new catalytic materials with the desired selectivity toward C=C or C=O bond hydrogenation. The interaction of this class of compounds with transition metals was investigated on α,β-unsaturated ketone Isophorone on Pd(111) as a prototypical system. In this study, infrared reflection-absorption spectroscopy (IRAS), near-edge x-ray absorption fine structure (NEXAFS) experiments and density functional theory calculations including van der Waals interactions (DFT+vdW) were combined to obtain detailed information on the binding of Isophorone to palladium at different coverages and on the effect of pre-adsorbed hydrogen on the binding and adsorption geometry. According to these experimental observations and the results of theoretical calculations, Isophorone adsorbs on Pd(111) in a flat-lying geometry at low coverages. With increasing coverage, both C=C and C=O bonds of Isophorone tilt with respect to the surface plane. The tilting is considerably more pronounced for the C=C bond on the pristine Pd(111) surface, indicating a prominent perturbation and structural distortion of the conjugated π system upon interaction with Pd. Pre-adsorbed hydrogen leads to higher tilting angles of both π bonds, which points to much weaker interaction of Isophorone with hydrogen pre-covered
Wiebke Riedel - One of the best experts on this subject based on the ideXlab platform.
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adsorption of Isophorone and trimethyl cyclohexanone on pd 111 a combination of infrared reflection absorption spectroscopy and density functional theory studies
Surface Science, 2016Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Swetlana Schauermann, Hansjoachim FreundAbstract:Abstract Understanding the interaction of α,β-unsaturated carbonyl compounds with late transition metals is a key prerequisite for rational design of new catalysts with desired selectivity towards C = C or C = O bond hydrogenation. The interaction of the α,β-unsaturated ketone Isophorone and the saturated ketone TMCH (3,3,5-trimethylcyclohexanone) with Pd(111) was investigated in this study as a prototypical system. Infrared reflection–absorption spectroscopy (IRAS) and density functional theory calculations including van der Waals interactions (DFT + vdW surf ) were combined to form detailed assignments of IR vibrational modes in the range from 3000 cm − 1 to 1000 cm − 1 in order to obtain information on the binding of Isophorone and TMCH to Pd(111) as well as to study the effect of co-adsorbed hydrogen. IRAS measurements were performed with deuterium-labeled ( d 5 -) Isophorone, in addition to unlabeled Isophorone and unlabeled TMCH. Experimentally observed IR absorption features and calculated vibrational frequencies indicate that Isophorone and TMCH molecules in multilayers have a mostly unperturbed structure with random orientation. At sub-monolayer coverages, strong perturbation and preferred orientations of the adsorbates were found. At low coverage, Isophorone interacts strongly with Pd(111) and adsorbs in a flat-lying geometry with the C = C and C = O bonds parallel, and a CH 3 group perpendicular, to the surface. At intermediate sub-monolayer coverage, the C = C bond is strongly tilted, while the C = O bond remains flat-lying, which indicates a prominent perturbation of the conjugated π system. Pre-adsorbed hydrogen leads to significant changes in the adsorption geometry of Isophorone, which suggests a weakening of its binding to Pd(111). At low coverage, the structure of the CH 3 groups seems to be mostly unperturbed on the hydrogen pre-covered surface. With increasing coverage, a conservation of the in-plane geometry of the conjugated π system was observed in the presence of hydrogen. In contrast to Isophorone, TMCH adsorbs in a strongly tilted geometry independent of the surface coverage. At low coverage, an adsorbate with a strongly distorted C = O bond is formed. With increasing exposure, species with a less perturbed C = O group appear.
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interaction of Isophorone with pd 111 a combination of infrared reflection absorption spectroscopy near edge x ray absorption fine structure and density functional theory studies
Journal of Physical Chemistry C, 2014Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Martin Oehzelt, Swetlana SchauermannAbstract:Atomistic level understanding of interaction of α,β-unsaturated carbonyls with late transition metals is a key prerequisite for rational design of new catalytic materials with the desired selectivity toward C═C or C═O bond hydrogenation. The interaction of this class of compounds with transition metals was investigated on α,β-unsaturated ketone Isophorone on Pd(111) as a prototypical system. In this study, infrared reflection–absorption spectroscopy (IRAS), near-edge X-ray absorption fine structure (NEXAFS) experiments, and density functional theory calculations including van der Waals interactions (DFT+vdW) were combined to obtain detailed information on the binding of Isophorone to palladium at different coverages and on the effect of preadsorbed hydrogen on the binding and adsorption geometry. According to these experimental observations and the results of theoretical calculations, Isophorone adsorbs on Pd(111) in a flat-lying geometry at low coverages. With increasing coverage, both C═C and C═O bonds ...
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interaction of Isophorone with pd 111 a combination of iras nexafs and dft studies
Journal of Physical Chemistry C, 2014Co-Authors: Karlheinz Dostert, Casey P Obrien, Wiebke Riedel, Aditya Savara, Alexandre Tkatchenko, Martin Oehzelt, Swetlana SchauermannAbstract:Atomistic level understanding of interaction of α,β-unsaturated carbonyls with late transition metals is a key prerequisite for rational design of new catalytic materials with the desired selectivity toward C=C or C=O bond hydrogenation. The interaction of this class of compounds with transition metals was investigated on α,β-unsaturated ketone Isophorone on Pd(111) as a prototypical system. In this study, infrared reflection-absorption spectroscopy (IRAS), near-edge x-ray absorption fine structure (NEXAFS) experiments and density functional theory calculations including van der Waals interactions (DFT+vdW) were combined to obtain detailed information on the binding of Isophorone to palladium at different coverages and on the effect of pre-adsorbed hydrogen on the binding and adsorption geometry. According to these experimental observations and the results of theoretical calculations, Isophorone adsorbs on Pd(111) in a flat-lying geometry at low coverages. With increasing coverage, both C=C and C=O bonds of Isophorone tilt with respect to the surface plane. The tilting is considerably more pronounced for the C=C bond on the pristine Pd(111) surface, indicating a prominent perturbation and structural distortion of the conjugated π system upon interaction with Pd. Pre-adsorbed hydrogen leads to higher tilting angles of both π bonds, which points to much weaker interaction of Isophorone with hydrogen pre-covered
