Galina Petrova | Kyoto University (original) (raw)
Papers by Galina Petrova
Journal of Physical Chemistry C, 2010
ABSTRACT
Nature Materials, 2011
Interactions of metal particles with oxide supports can radically enhance the performance of supp... more Interactions of metal particles with oxide supports can radically enhance the performance of supported catalysts. At the microscopic level, the details of such metal-oxide interactions usually remain obscure. This study identifies two types of oxidative metal-oxide interaction on well-defined models of technologically important Pt-ceria catalysts: (1) electron transfer from the Pt nanoparticle to the support, and (2) oxygen transfer from ceria to Pt. The electron transfer is favourable on ceria supports, irrespective of their morphology. Remarkably, the oxygen transfer is shown to require the presence of nanostructured ceria in close contact with Pt and, thus, is inherently a nanoscale effect. Our findings enable us to detail the formation mechanism of the catalytically indispensable Pt-O species on ceria and to elucidate the extraordinary structure-activity dependence of ceria-based catalysts in general.
Journal of Molecular Catalysis A-chemical, 2011
... Petkov, in: Ordered Porous Solids, V. Valchev, S. Mintova, M. Tsapacis (Eds.), Elsevier, Amst... more ... Petkov, in: Ordered Porous Solids, V. Valchev, S. Mintova, M. Tsapacis (Eds.), Elsevier, Amsterdam, 2008, pp. ... JE Knox, JB Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, RE Stratmann, O. Yazyev, AJ Austin, R. Cammi, C. Pomelli, JW Ochterski, RL Martin, K. Morokuma ...
Physical Chemistry Chemical Physics, 2010
Tetrahedral model iridium species [Ir(4)H(n)](q+) of different charge and hydrogen loading were d... more Tetrahedral model iridium species [Ir(4)H(n)](q+) of different charge and hydrogen loading were described at the density functional level. The energy of dissociative adsorption of hydrogen was calculated to vary in the small interval from -63 kJ mol(-1) to -77 kJ mol(-1) (per H atom). Adsorption of hydrogen on Ir(4) and Ir(4)(+) induces an oxidation of the metal moiety, whereas the highly charged cluster Ir(4)(3+) is reduced upon hydrogen adsorption. The ligand shell acts as charge buffer as the metal moieties of the complexes [Ir(4)H(12)](q+) with maximum hydrogen loading carry very similar effective charges, irrespective of the total charge q. Similar effects were confirmed to occur on small clusters of other 4d and 5d transition metals.
Journal of Molecular Graphics & Modelling, 2010
We describe automated procedures for the first stages of a systematic computational investigation... more We describe automated procedures for the first stages of a systematic computational investigation of reaction mechanisms. They include (i) selection of computational method and basis set based on statistical analysis of structural and energy data relating to experimental values, (ii) determination of all distinct conformations of transition states with large conformational freedom, and (iii) generation of unknown geometry of the transition states, based on pre-defined connectivity of the atoms involved in the reaction. For the conformational search we employed an efficient procedure for exploration of various possible conformations of the transition states and elimination of the equivalent structures in several steps using molecular-mechanical and quantum-mechanical methods. The procedure was applied to the determination of the structures of transition states and intermediates in the ammonolysis of monoformylated 1,2-ethanediol, which were subsequently used for identification of the lowest energy reaction paths. For the same reaction system we also used the approach for generation of the initial structures of transition states with unknown geometry. The reported procedures are implemented in the MolRan program suite.
Chemical Physics Letters, 2007
ABSTRACT
Chemical Physics Letters, 2007
ABSTRACT
Journal of Physical Chemistry C, 2008
ABSTRACT
Journal of Molecular Graphics & Modelling, 2011
The study reports a computational analysis of the influence of proton donor group adjacent to the... more The study reports a computational analysis of the influence of proton donor group adjacent to the reaction center during ester ammonolysis of an acylated diol as a model reaction for peptide bond formation. This analysis was performed using catalytic maps constructed after a detailed scanning of the available space around the reaction centers in different transition states, a water molecule acting as a typical proton donor. The calculations suggest that an adjacent proton donor center can reduce the activation barrier of the rate determining transition states by up to 7.2 kcal/mol, while no inhibition of the reaction can be achieved by such a group.
Topics in Catalysis, 2011
We review our computational studies at the DFT level on small isolated metal clusters of late tra... more We review our computational studies at the DFT level on small isolated metal clusters of late transition metals that contain atomic (H, C, O) or diatomic (CO, N2) ligands. These investigations were initiated by the clarification of the structure of iridium and rhodium clusters, as characterized by EXAFS, and then were extended to clusters of other transition metals (Ni, Ru, Pd, Os, Pt). The results suggest that a single H atom hardly changes the structure of a small metal cluster, while the presence of O and C impurity atoms causes large variations in the metal–metal distances. The adsorption of single atoms results in a partial oxidation of the metal moiety, yet addition of an atomic impurity only moderately modifies the electronic properties of small clusters, whereas stronger modifications of the properties are caused when the charge of the metal cluster is varied. The dissociative adsorption of larger amounts of hydrogen, up to 6 H2 molecules, on metal tetramers causes an elongation of the (average) inter-metallic distances, bringing them close to the experimental values. This body of computational results can be helpful for elucidating the structures of experimentally observed species and for rationalizing their electronic and catalytic properties.
Journal of Physical Chemistry C, 2010
ABSTRACT
Nature Materials, 2011
Interactions of metal particles with oxide supports can radically enhance the performance of supp... more Interactions of metal particles with oxide supports can radically enhance the performance of supported catalysts. At the microscopic level, the details of such metal-oxide interactions usually remain obscure. This study identifies two types of oxidative metal-oxide interaction on well-defined models of technologically important Pt-ceria catalysts: (1) electron transfer from the Pt nanoparticle to the support, and (2) oxygen transfer from ceria to Pt. The electron transfer is favourable on ceria supports, irrespective of their morphology. Remarkably, the oxygen transfer is shown to require the presence of nanostructured ceria in close contact with Pt and, thus, is inherently a nanoscale effect. Our findings enable us to detail the formation mechanism of the catalytically indispensable Pt-O species on ceria and to elucidate the extraordinary structure-activity dependence of ceria-based catalysts in general.
Journal of Molecular Catalysis A-chemical, 2011
... Petkov, in: Ordered Porous Solids, V. Valchev, S. Mintova, M. Tsapacis (Eds.), Elsevier, Amst... more ... Petkov, in: Ordered Porous Solids, V. Valchev, S. Mintova, M. Tsapacis (Eds.), Elsevier, Amsterdam, 2008, pp. ... JE Knox, JB Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, RE Stratmann, O. Yazyev, AJ Austin, R. Cammi, C. Pomelli, JW Ochterski, RL Martin, K. Morokuma ...
Physical Chemistry Chemical Physics, 2010
Tetrahedral model iridium species [Ir(4)H(n)](q+) of different charge and hydrogen loading were d... more Tetrahedral model iridium species [Ir(4)H(n)](q+) of different charge and hydrogen loading were described at the density functional level. The energy of dissociative adsorption of hydrogen was calculated to vary in the small interval from -63 kJ mol(-1) to -77 kJ mol(-1) (per H atom). Adsorption of hydrogen on Ir(4) and Ir(4)(+) induces an oxidation of the metal moiety, whereas the highly charged cluster Ir(4)(3+) is reduced upon hydrogen adsorption. The ligand shell acts as charge buffer as the metal moieties of the complexes [Ir(4)H(12)](q+) with maximum hydrogen loading carry very similar effective charges, irrespective of the total charge q. Similar effects were confirmed to occur on small clusters of other 4d and 5d transition metals.
Journal of Molecular Graphics & Modelling, 2010
We describe automated procedures for the first stages of a systematic computational investigation... more We describe automated procedures for the first stages of a systematic computational investigation of reaction mechanisms. They include (i) selection of computational method and basis set based on statistical analysis of structural and energy data relating to experimental values, (ii) determination of all distinct conformations of transition states with large conformational freedom, and (iii) generation of unknown geometry of the transition states, based on pre-defined connectivity of the atoms involved in the reaction. For the conformational search we employed an efficient procedure for exploration of various possible conformations of the transition states and elimination of the equivalent structures in several steps using molecular-mechanical and quantum-mechanical methods. The procedure was applied to the determination of the structures of transition states and intermediates in the ammonolysis of monoformylated 1,2-ethanediol, which were subsequently used for identification of the lowest energy reaction paths. For the same reaction system we also used the approach for generation of the initial structures of transition states with unknown geometry. The reported procedures are implemented in the MolRan program suite.
Chemical Physics Letters, 2007
ABSTRACT
Chemical Physics Letters, 2007
ABSTRACT
Journal of Physical Chemistry C, 2008
ABSTRACT
Journal of Molecular Graphics & Modelling, 2011
The study reports a computational analysis of the influence of proton donor group adjacent to the... more The study reports a computational analysis of the influence of proton donor group adjacent to the reaction center during ester ammonolysis of an acylated diol as a model reaction for peptide bond formation. This analysis was performed using catalytic maps constructed after a detailed scanning of the available space around the reaction centers in different transition states, a water molecule acting as a typical proton donor. The calculations suggest that an adjacent proton donor center can reduce the activation barrier of the rate determining transition states by up to 7.2 kcal/mol, while no inhibition of the reaction can be achieved by such a group.
Topics in Catalysis, 2011
We review our computational studies at the DFT level on small isolated metal clusters of late tra... more We review our computational studies at the DFT level on small isolated metal clusters of late transition metals that contain atomic (H, C, O) or diatomic (CO, N2) ligands. These investigations were initiated by the clarification of the structure of iridium and rhodium clusters, as characterized by EXAFS, and then were extended to clusters of other transition metals (Ni, Ru, Pd, Os, Pt). The results suggest that a single H atom hardly changes the structure of a small metal cluster, while the presence of O and C impurity atoms causes large variations in the metal–metal distances. The adsorption of single atoms results in a partial oxidation of the metal moiety, yet addition of an atomic impurity only moderately modifies the electronic properties of small clusters, whereas stronger modifications of the properties are caused when the charge of the metal cluster is varied. The dissociative adsorption of larger amounts of hydrogen, up to 6 H2 molecules, on metal tetramers causes an elongation of the (average) inter-metallic distances, bringing them close to the experimental values. This body of computational results can be helpful for elucidating the structures of experimentally observed species and for rationalizing their electronic and catalytic properties.
Journal of Physical Chemistry C, 2010
ABSTRACT
Nature Materials, 2011
Interactions of metal particles with oxide supports can radically enhance the performance of supp... more Interactions of metal particles with oxide supports can radically enhance the performance of supported catalysts. At the microscopic level, the details of such metal-oxide interactions usually remain obscure. This study identifies two types of oxidative metal-oxide interaction on well-defined models of technologically important Pt-ceria catalysts: (1) electron transfer from the Pt nanoparticle to the support, and (2) oxygen transfer from ceria to Pt. The electron transfer is favourable on ceria supports, irrespective of their morphology. Remarkably, the oxygen transfer is shown to require the presence of nanostructured ceria in close contact with Pt and, thus, is inherently a nanoscale effect. Our findings enable us to detail the formation mechanism of the catalytically indispensable Pt-O species on ceria and to elucidate the extraordinary structure-activity dependence of ceria-based catalysts in general.
Journal of Molecular Catalysis A-chemical, 2011
... Petkov, in: Ordered Porous Solids, V. Valchev, S. Mintova, M. Tsapacis (Eds.), Elsevier, Amst... more ... Petkov, in: Ordered Porous Solids, V. Valchev, S. Mintova, M. Tsapacis (Eds.), Elsevier, Amsterdam, 2008, pp. ... JE Knox, JB Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, RE Stratmann, O. Yazyev, AJ Austin, R. Cammi, C. Pomelli, JW Ochterski, RL Martin, K. Morokuma ...
Physical Chemistry Chemical Physics, 2010
Tetrahedral model iridium species [Ir(4)H(n)](q+) of different charge and hydrogen loading were d... more Tetrahedral model iridium species [Ir(4)H(n)](q+) of different charge and hydrogen loading were described at the density functional level. The energy of dissociative adsorption of hydrogen was calculated to vary in the small interval from -63 kJ mol(-1) to -77 kJ mol(-1) (per H atom). Adsorption of hydrogen on Ir(4) and Ir(4)(+) induces an oxidation of the metal moiety, whereas the highly charged cluster Ir(4)(3+) is reduced upon hydrogen adsorption. The ligand shell acts as charge buffer as the metal moieties of the complexes [Ir(4)H(12)](q+) with maximum hydrogen loading carry very similar effective charges, irrespective of the total charge q. Similar effects were confirmed to occur on small clusters of other 4d and 5d transition metals.
Journal of Molecular Graphics & Modelling, 2010
We describe automated procedures for the first stages of a systematic computational investigation... more We describe automated procedures for the first stages of a systematic computational investigation of reaction mechanisms. They include (i) selection of computational method and basis set based on statistical analysis of structural and energy data relating to experimental values, (ii) determination of all distinct conformations of transition states with large conformational freedom, and (iii) generation of unknown geometry of the transition states, based on pre-defined connectivity of the atoms involved in the reaction. For the conformational search we employed an efficient procedure for exploration of various possible conformations of the transition states and elimination of the equivalent structures in several steps using molecular-mechanical and quantum-mechanical methods. The procedure was applied to the determination of the structures of transition states and intermediates in the ammonolysis of monoformylated 1,2-ethanediol, which were subsequently used for identification of the lowest energy reaction paths. For the same reaction system we also used the approach for generation of the initial structures of transition states with unknown geometry. The reported procedures are implemented in the MolRan program suite.
Chemical Physics Letters, 2007
ABSTRACT
Chemical Physics Letters, 2007
ABSTRACT
Journal of Physical Chemistry C, 2008
ABSTRACT
Journal of Molecular Graphics & Modelling, 2011
The study reports a computational analysis of the influence of proton donor group adjacent to the... more The study reports a computational analysis of the influence of proton donor group adjacent to the reaction center during ester ammonolysis of an acylated diol as a model reaction for peptide bond formation. This analysis was performed using catalytic maps constructed after a detailed scanning of the available space around the reaction centers in different transition states, a water molecule acting as a typical proton donor. The calculations suggest that an adjacent proton donor center can reduce the activation barrier of the rate determining transition states by up to 7.2 kcal/mol, while no inhibition of the reaction can be achieved by such a group.
Topics in Catalysis, 2011
We review our computational studies at the DFT level on small isolated metal clusters of late tra... more We review our computational studies at the DFT level on small isolated metal clusters of late transition metals that contain atomic (H, C, O) or diatomic (CO, N2) ligands. These investigations were initiated by the clarification of the structure of iridium and rhodium clusters, as characterized by EXAFS, and then were extended to clusters of other transition metals (Ni, Ru, Pd, Os, Pt). The results suggest that a single H atom hardly changes the structure of a small metal cluster, while the presence of O and C impurity atoms causes large variations in the metal–metal distances. The adsorption of single atoms results in a partial oxidation of the metal moiety, yet addition of an atomic impurity only moderately modifies the electronic properties of small clusters, whereas stronger modifications of the properties are caused when the charge of the metal cluster is varied. The dissociative adsorption of larger amounts of hydrogen, up to 6 H2 molecules, on metal tetramers causes an elongation of the (average) inter-metallic distances, bringing them close to the experimental values. This body of computational results can be helpful for elucidating the structures of experimentally observed species and for rationalizing their electronic and catalytic properties.
Journal of Physical Chemistry C, 2010
ABSTRACT
Nature Materials, 2011
Interactions of metal particles with oxide supports can radically enhance the performance of supp... more Interactions of metal particles with oxide supports can radically enhance the performance of supported catalysts. At the microscopic level, the details of such metal-oxide interactions usually remain obscure. This study identifies two types of oxidative metal-oxide interaction on well-defined models of technologically important Pt-ceria catalysts: (1) electron transfer from the Pt nanoparticle to the support, and (2) oxygen transfer from ceria to Pt. The electron transfer is favourable on ceria supports, irrespective of their morphology. Remarkably, the oxygen transfer is shown to require the presence of nanostructured ceria in close contact with Pt and, thus, is inherently a nanoscale effect. Our findings enable us to detail the formation mechanism of the catalytically indispensable Pt-O species on ceria and to elucidate the extraordinary structure-activity dependence of ceria-based catalysts in general.
Journal of Molecular Catalysis A-chemical, 2011
... Petkov, in: Ordered Porous Solids, V. Valchev, S. Mintova, M. Tsapacis (Eds.), Elsevier, Amst... more ... Petkov, in: Ordered Porous Solids, V. Valchev, S. Mintova, M. Tsapacis (Eds.), Elsevier, Amsterdam, 2008, pp. ... JE Knox, JB Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, RE Stratmann, O. Yazyev, AJ Austin, R. Cammi, C. Pomelli, JW Ochterski, RL Martin, K. Morokuma ...
Physical Chemistry Chemical Physics, 2010
Tetrahedral model iridium species [Ir(4)H(n)](q+) of different charge and hydrogen loading were d... more Tetrahedral model iridium species [Ir(4)H(n)](q+) of different charge and hydrogen loading were described at the density functional level. The energy of dissociative adsorption of hydrogen was calculated to vary in the small interval from -63 kJ mol(-1) to -77 kJ mol(-1) (per H atom). Adsorption of hydrogen on Ir(4) and Ir(4)(+) induces an oxidation of the metal moiety, whereas the highly charged cluster Ir(4)(3+) is reduced upon hydrogen adsorption. The ligand shell acts as charge buffer as the metal moieties of the complexes [Ir(4)H(12)](q+) with maximum hydrogen loading carry very similar effective charges, irrespective of the total charge q. Similar effects were confirmed to occur on small clusters of other 4d and 5d transition metals.
Journal of Molecular Graphics & Modelling, 2010
We describe automated procedures for the first stages of a systematic computational investigation... more We describe automated procedures for the first stages of a systematic computational investigation of reaction mechanisms. They include (i) selection of computational method and basis set based on statistical analysis of structural and energy data relating to experimental values, (ii) determination of all distinct conformations of transition states with large conformational freedom, and (iii) generation of unknown geometry of the transition states, based on pre-defined connectivity of the atoms involved in the reaction. For the conformational search we employed an efficient procedure for exploration of various possible conformations of the transition states and elimination of the equivalent structures in several steps using molecular-mechanical and quantum-mechanical methods. The procedure was applied to the determination of the structures of transition states and intermediates in the ammonolysis of monoformylated 1,2-ethanediol, which were subsequently used for identification of the lowest energy reaction paths. For the same reaction system we also used the approach for generation of the initial structures of transition states with unknown geometry. The reported procedures are implemented in the MolRan program suite.
Chemical Physics Letters, 2007
ABSTRACT
Chemical Physics Letters, 2007
ABSTRACT
Journal of Physical Chemistry C, 2008
ABSTRACT
Journal of Molecular Graphics & Modelling, 2011
The study reports a computational analysis of the influence of proton donor group adjacent to the... more The study reports a computational analysis of the influence of proton donor group adjacent to the reaction center during ester ammonolysis of an acylated diol as a model reaction for peptide bond formation. This analysis was performed using catalytic maps constructed after a detailed scanning of the available space around the reaction centers in different transition states, a water molecule acting as a typical proton donor. The calculations suggest that an adjacent proton donor center can reduce the activation barrier of the rate determining transition states by up to 7.2 kcal/mol, while no inhibition of the reaction can be achieved by such a group.
Topics in Catalysis, 2011
We review our computational studies at the DFT level on small isolated metal clusters of late tra... more We review our computational studies at the DFT level on small isolated metal clusters of late transition metals that contain atomic (H, C, O) or diatomic (CO, N2) ligands. These investigations were initiated by the clarification of the structure of iridium and rhodium clusters, as characterized by EXAFS, and then were extended to clusters of other transition metals (Ni, Ru, Pd, Os, Pt). The results suggest that a single H atom hardly changes the structure of a small metal cluster, while the presence of O and C impurity atoms causes large variations in the metal–metal distances. The adsorption of single atoms results in a partial oxidation of the metal moiety, yet addition of an atomic impurity only moderately modifies the electronic properties of small clusters, whereas stronger modifications of the properties are caused when the charge of the metal cluster is varied. The dissociative adsorption of larger amounts of hydrogen, up to 6 H2 molecules, on metal tetramers causes an elongation of the (average) inter-metallic distances, bringing them close to the experimental values. This body of computational results can be helpful for elucidating the structures of experimentally observed species and for rationalizing their electronic and catalytic properties.