Article
Chemistry, Physical
Chuanyu Yan, Enzo Moretto, Oussema Kachouri, Jean-Luc Biagi, Jean-Sebastien Thomann, Francois Kayser, Reiner Dieden
Summary: This study demonstrates the use of solid-state nuclear magnetic resonance spectroscopy for studying dehydration and deuterium exchange at the liquid-solid interface. The results provide evidence of complete removal of physically adsorbed water molecules on the silica surface in the presence of DMSO, and satisfactory deuteration of silanol groups in the presence of a DMSO-D2O mixture. Additionally, the study develops a liquid-state NMR-based technique for quantifying moisture and hydroxyls on solids.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Chemistry, Physical
Monu Kaushik, Cesar Leroy, Zixuan Chen, David Gajan, Elena Willinger, Christoph R. Muller, Franck Fayon, Dominique Massiot, Alexey Fedorov, Christophe Coperet, Anne Lesage, Pierre Florian
Summary: This study reveals the atomic-scale structure and chemical properties of alumina films prepared by ALD on silica surface using organometallic chemistry and NMR techniques. The aluminum content and nature of acidic sites in the alumina films change with increasing ALD cycles, impacting the catalytic activity of heterogeneous catalysts.
CHEMISTRY OF MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Da -Wei Wu, Yong -Bo Yuan, Shuang Liu, Meng-Qiu Long, Yun-Peng Wang
Summary: In this study, first-principles calculations were performed on NiBr2 monolayer, and it was found that the electric polarization is related to the spin-orbital coupling effect, with the Br atomic orbitals strongly hybridized with Ni orbitals being the major contributor to the polarization.
Article
Chemistry, Inorganic & Nuclear
Akira Imaizumi, Akinobu Nakada, Takeshi Matsumoto, Toshiyuki Yokoi, Ho-Chol Chang
Summary: This study demonstrates a simple thermal synthesis of porous aluminosilicates from a single-source spiro-7-type molecular precursor. The synthesized aluminosilicates show low carbon content, large surface area, and improved catalytic activity.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Woojin Choi, Sungwoo Lee, Dong-Hoon Han, Hong Taek Lim, Hwanyeol Park, Gun-Do Lee
Summary: DFT calculations were used to study the dissociative reactions of TiCl4 on non-hydroxylated and hydroxylated ?-Al2O3 surfaces. It was found that residual Cl atoms hindered adsorption on the non-hydroxylated surface, while hydroxyl functional groups lowered activation energy for the reactions. This highlights the importance of understanding electronic interactions between reactive molecules and surface functional groups for future memory device design.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
E. A. Peterson, J. B. Haber, J. B. Neaton
Summary: The study investigates the physical mechanism behind valley splitting induced by magnetic atoms on the surface of monolayer TMDs, with DFT calculations evaluating the impact of different parameters of magnetic atoms on the near-valence band edge energies. It is concluded that large valley splittings can be achieved through a superexchange mechanism, depending on the overlap of TMD Bloch states with the localized d states of the magnetic atom and the out-of-plane component of the magnetic moment.
Article
Chemistry, Physical
Xinli Wang, Canying Cai, Guangwen Zhou
Summary: Through first-principles calculations based on density functional theory, the study reveals the impact of water vapor on the formation, migration, and aggregation of atomic defects in aluminum oxide phases during high-temperature oxidation. The atomic origins of water vapor in inducing faster alumina scale growth compared to dry oxygen are elucidated, suggesting ways to manipulate the oxidation kinetics of alumina-forming alloys by controlling oxidizing atmospheres.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Zixuan Chen, Nora K. Zimmerli, Muhammad Zubair, Alexander V. Yakimov, Snaedis Bjorgvinsdottir, Nicholas Alaniva, Elena Willinger, Alexander B. Barnes, Nicholas M. Bedford, Christophe Coperet, Pierre Florian, Paula M. Abdala, Alexey Fedorov, Christoph R. Mueller
Summary: Gallia-based shells with varying thickness were prepared using atomic layer deposition (ALD) and their atomic-scale structure was studied. The abundance and strength of Lewis acid sites and Bronsted acid sites in the shells were found to correlate with the catalytic performance. This provides insights for the rational design of active Ga-based catalysts.
CHEMISTRY OF MATERIALS
(2023)
Article
Physics, Applied
Peng Xu, Fuxiang Liu
Summary: Toxicity and chemical stability are concerns for organic-inorganic hybrid perovskites, leading to the investigation of alternative CH3NH3)2SnI6. First-principles calculations reveal its electronic properties and conditions for different applications, such as electron transporting and photovoltaic. Suitable materials for use in MA(2)SnI(6) based solar cells include ICBA and Spiro as ETM and hole transporting material, respectively.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Nicolas Merle, Tarnuma Tabassum, Susannah L. Scott, Alessandro Motta, Kai Szeto, Mostafa Taoufik, Regis Michael Gauvin, Laurent Delevoye
Summary: This study provides a qualitative and quantitative assessment of the hydroxyl groups on the surface of γ-Al2O3 and describes the principal configurations of hydroxyl groups in unprecedented detail. The relationship between hydroxyl structures and the molecular-level structures of active sites in catalytic alkane metathesis is discussed.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Nanoscience & Nanotechnology
Ming Cheng, Zhenhua Zhang, Xiaojuan Yuan, Yong Liu, Zhihong Lu, Rui Xiong, Jing Shi
Summary: This study investigated the interface structure and MAE properties of Co2FeAl/MgAl2O4 heterostructures with high PMA using first principles calculations. The results showed that the Co-O interface can induce a large PMA effect, but is a metastable structure, while the FeAl-O interface has a smaller PMA effect. Additionally, enhancing the PMA effect of the FeAl-O interface can be achieved by adjusting strain, electric field, and doping.
Article
Chemistry, Applied
Ignacio J. Chevallier-Boutell, Gustavo A. Monti, Horacio Corti, Jimena A. Olmos-Asar, Maria B. Franzoni, Rodolfo H. Acosta
Summary: Alkanes interactions with silica mesopores walls affect geometric tortuosity measurements, with adsorption energy depending on molecular length and shape, and weighted energy correlating with pore diameter. Accuracy of geometric tortuosity determination using this methodology is found to be impacted for pore diameters smaller than approximately 6 nm.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Chemistry, Physical
Liuru Fang, Yao Guo, Shiding Zhang, Yuepeng Lv, Yuanbin Xue, Xiaojing Bai, Jianxin Li, Changwei Lai, Yuhua Wang
Summary: In this study, Cs2AgBiBr6/M3C2 heterostructures were constructed and characterized using density functional theory (DFT) and experimental studies. The results showed that AgBiBr3/M3C2 heterostructures exhibited superior interfacial properties compared to Cs2BiBr3/M3C2 heterostructures, with smaller interfacial distance, higher binding energy, and better charge transfer ability. Among the AgBiBr3/M3C2 heterostructures, AgBiBr3/Ti3C2 and AgBiBr3/Zr3C2 showed the best binding energy and charge transfer ability. Furthermore, all the constructed heterostructures showed improved light absorption coefficient, broadened visible light absorption range, and reduced effective mass of the charge carriers. The experimental synthesis of Cs2AgBiBr6/Ti3C2 composite materials confirmed the feasibility of the theoretical models. These results provide valuable theoretical guidance for developing high-performance Cs2AgBiBr6/M3C2 heterostructures in optoelectronic perovskite devices.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Cheng Tang, Lei Zhang, Yalong Jiao, Chunmei Zhang, Stefano Sanvito, Aijun Du
Summary: By combining particle swarm optimization with first-principles calculations, a stable 2D polar half-metal, quintuple layered Co2Se3 monolayer, has been predicted. This material exhibits XY magnetism and out-of-plane piezoelectricity, showing multiferroic properties and great potential in advanced multiferroic applications.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Chemistry, Physical
Lei Li, Xueyan Yan, Bingzheng Yang, Sen Yang, Alex A. Volinsky, Xiaolu Pang
Summary: The thermal stability of AlN substrates coated with active metal was studied using first principles calculations. The results showed good thermal stability of the interface at elevated temperatures, and an orientation dependence of the interface elasticity was found. This study is helpful for the development of novel high-power microelectronic devices.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Adrien Hellier, Celine Chizallet, Pascal Raybaud
Summary: In this study, the stability of platinum-based catalysts under calcination and reduction conditions was investigated using density functional theory. The results showed that the stability and nature of platinum species were highly dependent on the activation conditions, with different temperatures leading to different forms of platinum under oxygen and hydrogen environments.
Article
Chemistry, Physical
Ekaterina Galand, Fabien Caron, Etienne Girard, Antoine Daudin, Mickael Rivallan, Pascal Raybaud, Jean-Marc Schweitzer, Yves Schuurman
Summary: A Langmuir-Hinshelwood kinetic model is established to study the selective hydrodesulfurization (HDS) of fluidized catalytic cracking gasoline. The model takes into account 16 different reactions and adequately reproduces the experimental product distribution by determining rate constants and adsorption constants. The model is used to predict the impact of operating conditions on the selectivity, with an optimum desulfurization selectivity at approximately 30-50% 3MT conversion and low temperature (170 degrees C) being favorable for the HDS selectivity.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Pinelopi Moutzouri, Manuel Cordova, Bruno Simoes de Almeida, Daria Torodii, Lyndon Emsley
Summary: One key bottleneck of solid-state NMR spectroscopy is the broadness of H-1 NMR spectra of organic solids due to dipolar couplings. A new approach called PIP was suggested to address this problem by mapping errors leading to dipolar broadening and removing them in a correlation experiment. By extending the PIP approach to a second dimension using deep learning, high resolution H-1-H-1 double-quantum/single-quantum dipolar correlation and spin-diffusion spectra were obtained with significantly higher resolution than the corresponding spectra at 100 kHz MAS, allowing the identification of previously overlapped isotropic correlation peaks.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Celine Chizallet, Christophe Bouchy, Kim Larmier, Gerhard Pirngruber
Summary: The article focuses on the molecular views of the mechanism behind catalytic transformations facilitated by BrOnsted acid sites in zeolites. The authors use advanced kinetic analysis, in situ and operando spectroscopies, and quantum chemistry calculations to gain insights into these transformations. Specific reactions involving alkenes, alkanes, aromatic molecules, alcohols, and polyhydroxy molecules are discussed, with an emphasis on C-C, C-H, and C-O bond breaking and formation. The article also highlights future challenges and the goal of designing improved zeolite-based BrOnsted acid catalysts.
Article
Chemistry, Multidisciplinary
Seraphine B. X. Y. Zhang, Christophe Coperet
Summary: Non-oxidative coupling of methane (NOCM) is a highly researched reaction that is hindered by harsh reaction conditions and limited catalyst stability. Recent studies have highlighted the importance of catalyst nature and reaction conditions, with metal carbides playing a key role in the incorporation of carbidic carbon. This perspective provides an overview of proposed mechanistic pathways and considerations for experiment conditions, aiming to facilitate a rational catalyst design platform for NOCM.
Article
Chemistry, Physical
Thomas Pigeon, Gabriel Stoltz, Manuel Corral-Valero, Ani Anciaux-Sedrakian, Maxime Moreaud, Tony Lelievre, Pascal Raybaud
Summary: In this study, a method for computing accurate rate constants for catalytic events at surface was proposed. The method combined adaptive multilevel splitting (AMS) rare event sampling technique and ab initio molecular dynamics. Various approaches were used to build reaction coordinates, and a case study on the conformation change and dissociation of water molecule on γ-alumina (100) surface was conducted to evaluate the proposed method. The calculated rate constants and transition mechanisms were compared with the results obtained from a conventional static approach. It was found that the AMS method can provide rate constants smaller by up to 2 orders of magnitude due to entropic effects.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Multidisciplinary
Zachariah J. Berkson, Ran Zhu, Christian Ehinger, Lukas Latsch, Stefan P. Schmid, Darryl Nater, Stephan Pollitt, Olga V. Safonova, Snaedis Bjorgvinsdottir, Alexander B. Barnes, Yuriy Roman-Leshkov, Gregory A. Price, Glenn J. Sunley, Christophe Coperet
Summary: This article investigated the relationship between olefin metathesis activity of silica-supported molybdenum oxides and metal loading and preparation conditions. Results showed that similar catalysts with different compositions exhibit different reaction properties. The catalyst synthesized via surface organometallic chemistry showed better performance than a classical catalyst with similar metal loading. Solid-state Mo-95 NMR analysis revealed four distinct surface Mo dioxo sites with different distributions depending on the catalyst preparation methods. The intensity of a specific deshielded Mo-95 NMR signal was linked to reducibility and catalytic activity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Ana T. F. Batista, Thomas Pigeon, Jordan Meyet, Dorothea Wisser, Mickael Rivallan, David Gajan, Leonor Catita, Fabrice Diehl, Anne-Sophie Gay, Anne Lesage, Pascal Raybaud, Celine Chizallet
Summary: We use DFT calculations and proton solid-state NMR experiments to determine the exact location and spatial proximity of hydroxyl groups on gamma-alumina crystallites. We find that the hydroxyl groups are predominantly located on edges, free from the H-bond network. Chlorination selectively occurs on edges and lateral facets, resulting in the disappearance of the hydroxyl groups and disruption of the H-bond network.
Article
Chemistry, Multidisciplinary
Moritz Bernhardt, Lukas Latsch, Boris Le Guennic, Christophe Coperet
Summary: This work models surface sites with ten neutral complexes and investigates their potential as single-molecule magnets. The results show that the spatial position of the anionic ligands significantly influences the magnetic properties, while the neutral ligands have a minor role.
HELVETICA CHIMICA ACTA
(2023)
Article
Engineering, Chemical
Quirin Grossmann, Valentina Stampi-Bombelli, Alexander Yakimov, Scott Docherty, Christophe Coperet, Marco Mazzotti
Summary: The optimization of the air-solid contactor is crucial for improving the efficiency of the direct air capture (DAC) process. Two forms of contactors, pellets and wash-coated honeycomb monoliths, are prepared for comparison and potential optimization. The results show that the wash-coated monoliths have similar CO2 uptake compared to the pellets, but exhibit better adsorption kinetics due to their hierarchical pore structure, making them promising candidates for enhancing the efficiency of DAC processes.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Biochemical Research Methods
Bruno Simoes de Almeida, Daria Torodii, Pinelopi Moutzouri, Lyndon Emsley
Summary: The role of 1H solid-state NMR in structure elucidation of solids is becoming more important, especially with the availability of faster magic-angle spinning rates (MAS) which improve 1H detected assignment strategies. However, the current 1H spectral resolution is still relatively low. This study investigates the factors limiting proton linewidths and line shapes in MAS experiments with five different samples and identifies the different contributions through one-and two-dimensional experiments.
JOURNAL OF MAGNETIC RESONANCE
(2023)
Article
Chemistry, Physical
Alberto Ricchebuono, Eleonora Vottero, Andrea Piovano, Elena Groppo, Pascal Raybaud, Ceïline Chizallet
Summary: This article evaluates the performance of several low-cost methods in reproducing structural features of Pt nanoparticles of different sizes, and finds that some methods show a preference for amorphous geometries.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Seraphine B. X. Y. Zhang, Quentin Pessemesse, Lukas Latsch, Konstantin M. Engel, Wendelin J. Stark, Alexander P. van Bavel, Andrew D. Horton, Pierre-Adrien Payard, Christophe Coperet
Summary: Transition metal carbides, such as Mo and W carbides, exhibit excellent properties in terms of hardness, thermal stability, and conductivity, making them popular in catalytic applications. This study reveals the active involvement of carbidic carbon in the formation of C-2 products during methane coupling at high temperature, highlighting the importance of carbon diffusivity and exchange capability on catalyst performance. Mo carbide (Mo2C) shows stable C-2 selectivity over time due to fast carbon diffusion dynamics, while W carbide (WC) exhibits loss of selectivity due to slow diffusion. Overall, this study provides evidence for a Mars-Van Krevelen type mechanism in the non-oxidative coupling of methane.
Article
Chemistry, Multidisciplinary
Wei Zhou, Scott R. Docherty, Christian Ehinger, Xiaoyu Zhou, Christophe Coperet
Summary: Rh-based catalysts modified by Mn were studied for CO2 hydrogenation. The addition of Mn shifts the products from pure CH4 to a mixture of methane and oxygenates. In situ XAS confirms the presence of atomically dispersed Mn-II in the vicinity of metallic Rh nanoparticles, which induces the oxidation of Rh to form the Mn-O-Rh interface under reaction conditions. The formed interface is proposed to be key to maintaining Rh+ sites and promoting the formation of CO and alcohols.
