Article
Chemistry, Physical
Renwei Li, Qicheng Chen, Liang Ouyang, Yulong Ding
Summary: This study investigated the ideal work of adhesion, interfacial energy, charge density, charge density difference and partial density of states at the γ-Fe (111)/α-Al2O3 (0001) interface using first-principles calculations. Three different interface types were identified, with the O-terminated interface exhibiting the highest bonding strength. The electron concentration order was found to be O->Al2->Al1-terminated, reflecting differences in interactions at the interface.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Florian Kraushofer, Matthias Meier, Zdenek Jakub, Johanna Huetner, Jan Balajka, Jan Hulva, Michael Schmid, Cesare Franchini, Ulrike Diebold, Gareth S. Parkinson
Summary: This study investigates the (111) facet of magnetite (Fe3O4) and reveals three new surface structures that are more favorable under reducing conditions. The new structures change the coordination of iron atoms to a tetrahedral configuration. Atomically-resolved microscopy confirms the presence of tetrahedral iron atoms capped by 3-fold coordinated oxygen atoms. This discovery explains the inert nature of the reduced patches.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Cameron J. Owen, Stephen J. Jenkins
Summary: The study focuses on the adsorption behavior of single-atom catalysts on CeO2 surfaces, using gold catalysts as a reference. The results help to understand the performance of oxide-supported single-atom catalysts.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Maksim G. Kostenko, Aleksandr Gusev, Aleksey Lukoyanov
Summary: The study investigated various thermodynamically stable and metastable phases in nonstoichiometric tantalum carbide, along with phase transition channels and carbon atom distribution functions. It calculated the elastic stiffness constants for all phases and analyzed the mechanical stability of the materials, as well as the relationship between Debye temperatures and heat capacity with varying vacancy concentration.
Article
Materials Science, Multidisciplinary
Tilman Kisslinger, Alexandra Schewski, Andreas Raabgrund, Hannah Loh, Lutz Hammer, M. Alexander Schneider
Summary: This article describes the interaction between tellurium and a platinum surface during the production of transition-metal dichalcogenides by molecular beam epitaxy. The study identifies stable surface telluride phases formed when a submonolayer amount of tellurium is reacted with a platinum surface. The atomic structures of these telluride phases are determined using various techniques and demonstrate the current state-of-the-art for low-energy electron diffraction structural analyses.
Article
Chemistry, Multidisciplinary
Aditya Wibawa Sakti, Chien-Pin Chou, Yoshifumi Nishimura, Hiromi Nakai
Summary: The study used the density-functional tight-binding method to estimate the free-energy barriers of oxygen diffusion in bulk CeO2 and on a (111)-CeO2 surface. Results showed that the diffusion in the bulk CeO2 is faster than that on the (111)-CeO2 surface, with activation barriers of 7.4 and 31.6 kcal/mol, respectively.
Article
Chemistry, Physical
Noah Baumann, Jinggang Lan, Marcella Iannuzzi
Summary: The first principles simulations of carbon dioxide adsorbed on the ceria (CeO2) (111) surface were discussed in terms of structural features, stability, charge transfer, and vibrational modes, using different density functional theory methods. The electronic structure of the reduced ceria surface was obtained by introducing oxygen vacancies, and bent CO2 configurations near the surface oxygen vacancy were identified as the most stable minima. The concentration of oxygen vacancies on the surface directly impacts the relative stability of potential adsorption configurations, and the vibrational analyses showed promising agreement with previous theoretical and experimental results.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Maxim G. Kostenko, Jingyu Li, Zhi Zeng, Yongsheng Zhang, Sergey V. Sharf, Aleksandr I. Gusev, Alexey V. Lukoyanov
Summary: In this study, a theoretical search for ordered phases in hafnium carbide was conducted using the evolutionary algorithm USPEX for crystal structure prediction. Multiple thermodynamically stable and near-equilibrium compounds were identified. It was found that ordered vacancies do not deteriorate the mechanical properties of hafnium carbide, and ordered phases with vacancy concentrations less than 16.7% exhibit higher hardness compared to defect-free HfC.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
V. Koller, C. Sack, P. Lustemberg, M. V. Ganduglia-Pirovano, H. Over
Summary: This study investigates the impact of HCl oxidation reaction on the surface structure of ceria catalyst, revealing that chlorine adsorbs in the surface oxygen vacancies with high adsorption energy, and the water formation ability depends on the reduction degree of the catalyst.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
C. W. Galdino, D. C. Freitas, C. P. C. Medrano, D. R. Sanchez, R. Tartaglia, L. P. Rabello, A. A. Mendonca, L. Ghivelder, M. A. Continentino, M. J. M. Zapata, C. B. Pinheiro, G. M. Azevedo, J. A. Rodriguez-Velamazan, G. Garbarino, M. Nunez-Regueiro, E. Granado
Summary: This study investigates the charge ordering phenomenon in a homometallic Co ludwigite, confirming the mixed-valent character of Co ions and observing smaller Co ions at the M4 site at low temperatures. As temperature increases, the size difference between Co ions at M4 and M2 sites decreases, indicating gradual charge redistribution within the structure. Structural disorder and broadened vibrational modes are observed at medium to high temperatures, along with consistent local Co-O distance distribution.
Article
Physics, Applied
Lihua Gao, Xiangfa Zhang, Mingzhi Wang, Faming Gao
Summary: The study found that the Knoop hardness of amber cubic boron nitride single crystals exhibits significant crystal orientation dependence on the {111} plane, with the minimum value appearing about 5 degrees away from ⟨110⟩ directions. Raman spectra measurements of cubic boron nitrides help explain the hardening of samples.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Yueyang Wang, Xiaoyan Ren, Bojie Jiang, Meng Deng, Xingju Zhao, Rui Pang, S. F. Li
Summary: Magnetic single-atom catalysts (MSAC) play a crucial role in catalytic processes, especially in cases involving spin selection. By utilizing the interface of the porous g-C3N4/CeO2(111) heterostructure, high-performance MSAC for O-2 activation and CO oxidation can be achieved through a delicate synergistic mechanism of charge transfer and spin selection.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Ziyang Wei, John Mark P. Martirez, Emily A. Carter
Summary: This article introduces the random phase approximation (RPA) as a method for treating electron correlation, which has been shown to outperform standard density functional theory (DFT) approximations in cases such as extended surfaces. By using sub-system embedding schemes, the RPA can be used to simulate heterogeneous reactions at a reduced computational cost. The authors explore two embedded RPA approaches, periodic emb-RPA and cluster emb-RPA, and validate them in the H-2 dissociative adsorption on Cu(111) surface, finding that cluster emb-RPA accurately reproduces the energy profile while significantly reducing computational cost.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Qi Gao, Wenhui Li, Pengfei Liu, Qiang Wang, Yanhui Yang
Summary: Interfacial structures, interactions, and catalytic properties of CeO2/Cu(1 1 1) composites were investigated using DFT + U calculations. The study found that the interfacial interaction between CeO2(1 1 1) and Cu(1 1 1) substrate increased linearly with the increase of CeO2(1 1 1) thickness. Strong interfacial interaction and charge transfer were identified as key factors for the good stability and excellent catalytic activity of CeO2/Cu catalyst.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
De-Ren Chu, Zhi-Qiang Wanga, Xue-Qing Gonga
Summary: This study investigated the direct CO oxidation behavior on four types of CeO2(111) surface steps using density functional theory (DFT) calculations. The results showed that CO adsorption can be enhanced at step edges through the alignment of C-O and surface Ce-O bonds. The reactivities of step edges on the CeO2(111) surface were found to be similar to those of the corresponding extended facets. Oxygen sites at step edges with lower coordination numbers were found to have smaller vacancy formation energies and higher reactivities. Additionally, the Ce 4f orbital energy level was found to decrease after CO adsorption on a specific type of step, contributing to its superior catalytic activity towards CO oxidation. The unique role of CeO2(111) steps in influencing reactant adsorption, activation barriers, product desorption, and overall CO catalytic oxidation activities was revealed. These findings may inspire further research on the structure-reactivity relationships over surface defect sites on rare-earth oxide catalysts.
Article
Chemistry, Physical
Feng Zhang, Ramon A. Gutierrez, Pablo G. Lustemberg, Zongyuan Liu, Ning Rui, Tianpin Wu, Pedro J. Ramirez, Wenqian Xu, Hicham Idriss, M. Veronica Ganduglia-Pirovano, Sanjaya D. Senanayake, Jose A. Rodriguez
Summary: The study shows that Pt/CeO2 systems can effectively capture CO2 and CH4 at room temperature and serve as stable catalysts for the MDR process at 500 degrees Celsius. The Pt-CeO2 interface not only facilitates methane dissociation but also directly participates in the adsorption and dissociation of CO2, enabling the MDR catalytic cycle. The presence of elements with different chemical natures at the metaloxide interface allows for truly cooperative interactions in activating C-O and C-H bonds.
Article
Chemistry, Multidisciplinary
David C. Grinter, Michael Allan, Hyun Jin Yang, Agustin Salcedo, Gustavo E. Murgida, Bobbie-Jean Shaw, Chi L. Pang, Hicham Idriss, M. Veronica Ganduglia-Pirovano, Geoff Thornton
Summary: A Ce=O terminated ceria surface was observed in this study, revealing a key feature in the reconstruction of ceria islands and potentially shedding light on the unique catalytic properties of ceria-based systems.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Correction
Chemistry, Physical
Pablo G. Lustemberg, Feng Zhang, Ramon A. Gutierrez, Pedro J. Ramirez, Sanjaya D. Senanayake, Jose A. Rodriguez, M. Veronica Ganduglia-Pirovano
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Review
Chemistry, Multidisciplinary
Marc Ziemba, Christian Schilling, M. Veronica Ganduglia-Pirovano, Christian Hess
Summary: Ceria plays a crucial role in enhancing oxidation activity in catalysts, but identifying active sites remains a challenge. Recent studies have made significant progress in understanding the process of oxygen activation on ceria surfaces through a combination of experimental and theoretical approaches. The facet-dependent adsorption and activation of gas-phase oxygen on ceria has been revealed, providing important insights into the mechanisms involved.
ACCOUNTS OF CHEMICAL RESEARCH
(2021)
Article
Physics, Condensed Matter
Patricia Perez-Bailac, Pablo G. Lustemberg, M. Veronica Ganduglia-Pirovano
Summary: The study investigates the dependence of the relative stability of surface and subsurface oxygen vacancies in CeO2 on crystal facets. The results show that the preference of vacancies for surface or subsurface sites is facet- and concentration-dependent, with corresponding locations of Ce3+ polarons. The stability of vacancies on different facets is influenced by packing density, lattice relaxation effects, and localization of excess charge.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Chemistry, Physical
Pablo G. Lustemberg, Zhongtian Mao, Agustin Salcedo, Beatriz Irigoyen, M. Veronica Ganduglia-Pirovano, Charles T. Campbell
Summary: Research has shown that cationic Ni atoms in clusters at step edges on the CeO2(111) surface are the most active sites for methane conversion reactions, with their small size and high Ni chemical potential contributing to their activity. Density functional theory calculations have clarified the reasons behind this observation, highlighting the importance of the size and morphology of supported Ni nanoparticles, strong Ni-support bonding, and charge transfer at step edges for high catalytic activity, particularly in the activation barrier for C-H bond cleavage during CH4 dissociative adsorption. This knowledge is expected to inspire the development of more efficient catalysts for these reactions.
Article
Chemistry, Physical
Agustin Salcedo, Pablo G. Lustemberg, Ning Rui, Robert M. Palomino, Zongyuan Liu, Slavomir Nemsak, Sanjaya D. Senanayake, Jose A. Rodriguez, M. Veronica Ganduglia-Pirovano, Beatriz Irigoyen
Summary: Ni/CeO2 catalysts show high activity for methane steam reforming at relatively low temperatures, effectively preventing coke formation, with hydroxyl-assisted CO formation providing a low-barrier pathway to prevent carbon accumulation.
Correction
Physics, Multidisciplinary
Pablo G. Lustemberg, Philipp Plessow, Yuemin Wang, Chengwu Yang, Alexei Nefedov, Felix Studt, Christof Woll, M. Veronica Ganduglia-Pirovano
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Jorge Cored, Jaime Mazario, Cristina Cerda-Moreno, Pablo G. Lustemberg, M. Veronica Ganduglia-Pirovano, Marcelo E. Domine, Patricia Concepcion
Summary: Enhanced methanol production is achieved by using a specific precursor catalyst, leading to the stabilization of Cu+ ions under reaction conditions, and the importance of monodentate formate species in methanol synthesis is highlighted.
Article
Chemistry, Physical
V. Koller, C. Sack, P. Lustemberg, M. V. Ganduglia-Pirovano, H. Over
Summary: This study investigates the impact of HCl oxidation reaction on the surface structure of ceria catalyst, revealing that chlorine adsorbs in the surface oxygen vacancies with high adsorption energy, and the water formation ability depends on the reduction degree of the catalyst.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Pablo G. Lustemberg, Sanjaya D. Senanayake, Jose A. Rodriguez, M. Veronica Ganduglia-Pirovano
Summary: Efficient activation of methane and water dissociation are crucial in catalytic reactions. Adding copper to Ni/CeO2 surfaces can manipulate the activation barrier of CHx species, while water dissociation is not affected. Ni3Cu1/CeO2 model catalyst shows higher selectivity and lower activation barrier for methane oxidation to methanol.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Editorial Material
Physics, Condensed Matter
Paola Luches, Maria Veronica Ganduglia-Pirovano
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Julia Vecchietti, Patricia Perez-Bailac, Pablo G. Lusternberg, Esteban L. Fornero, Laura Pascual, Marta Bosco, Arturo Martinez-Arias, M. Veronica Ganduglia-Pirovano, Adrian L. Bonivardi
Summary: The ethanol surface reaction over CeO2 nanooctahedra and nanocubes was studied using infrared spectroscopy, mass spectrometry, and density functional theory calculations. The results show that the production of H2 is 2.4 times higher on CeO2-NC than on CeO2-NO, which can be explained by the different types of adsorbed ethoxy species on the different surfaces. The study also reveals the different pathways for H2 formation on the two surfaces of CeO2 nanoshapes.
Article
Chemistry, Physical
Pablo G. Lustemberg, Chengwu Yang, Yuemin Wang, Christof Woll, M. Veronica Ganduglia-Pirovano
Summary: This review focuses on the adsorption of CO on oxidized and reduced CeO2 single crystal surfaces, specifically examining CO coverage and the accuracy of quantum-mechanical methods in describing the IR vibrational frequency of CO. By comparing with experimental data, the study successfully assigns the CO vibrational bands observed on these surfaces. The results show that CO adsorption is greatly influenced by the surface structure and the presence of oxygen vacancies in cerium oxide.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Marc Ziemba, M. Veronica Ganduglia-Pirovano, Christian Hess
Summary: The study investigated the mechanism of the low-temperature water-gas shift reaction over Au/CeO2 catalysts with different ceria terminations. Results showed that the presence of gold on different facets of ceria played a facet-dependent role in oxygen dynamics, suggesting that surface properties have a significant impact on reactivity. The study also highlighted the importance of factors such as dissociative adsorption of water and desorption of CO2/H2 in the reaction process.
FARADAY DISCUSSIONS
(2021)
