Article
Chemistry, Physical
Christine Khoury, Samuel Holton, Dina Shpasser, Elior Hallo, Ambarish Kulkarni, Friederike C. Jentoft, Oz M. Gazit
Summary: The cooperative interactions of isolated tin and titanium sites on silica with grafted primary amines can be tuned by changing the immediate chemical environment of the metal sites. The interactions between the sites can be governed by tethering various size organic ligands to the metal sites, and the concentration of NH3+ is directly correlated with the activity and selectivity of the reaction. The presence of water near the metal sites and resulting hydrolysis play a crucial role in enabling these cooperative interactions.
Article
Chemistry, Multidisciplinary
Chen Lei, Andreas Erlebach, Federico Brivio, Lukas Grajciar, Zdenek Tosner, Christopher J. Heard, Petr Nachtigall
Summary: Solid state (ss-) Al-27 NMR is a valuable tool for characterizing zeolites, but its interpretation is complex and aluminum distributions are difficult to determine. Computational modeling has become popular to support experimental characterization, but simplifying assumptions are often made without justification. This study evaluates the effects of different models on the prediction of Al-27 NMR chemical shifts in zeolites and highlights the importance of operando modeling and considering factors like water loading, temperature, and cation characteristics. Machine learning regression is used to develop a relationship between chemical shifts and structural parameters, allowing for accurate prediction from dynamic simulations.
Article
Chemistry, Physical
Huan Yan, Selim Alayoglu, Weiqiang Wu, Yongbo Zhang, Eric Weitz, Peter C. Stair, Justin M. Notestein
Summary: The study discovered that depositing differently sized boronic acids into the micropores of silica supports results in different distributions of surface borate species after calcination. These materials exhibit a wide range of rates in ODHP but similar selectivity, indicating they differ only in the numbers of active sites. The correlation between identified features and catalyst activity confirms hydroxylated nonring boron as the likely active site, providing a target for future catalyst syntheses.
Article
Materials Science, Multidisciplinary
Guangyao Huang, Zhibo Zhang, Kaiwen Kang, Zhanqiu Tan, Hong Zhu, Valochko Alexander, Kaihong Zheng, Zhiqiang Li, Herbert M. Urbassek
Summary: In this study, the transport of carbon in aluminum carbide was investigated using density functional theory, revealing the growth mechanism. The diffusion of carbon was found to exhibit strong anisotropy, consistent with experimental results. A growth model was established to qualitatively and quantitatively explain the growth of aluminum carbide.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Alexandros Mortis, Cacilia Maichle-Mossmer, Reiner Anwander
Summary: A series of new yttrium donor adduct complexes were successfully synthesized and fully characterized, with two chosen for surface organometallic chemistry research. Mesoporous nanoparticles were used as a support material, with various characterization techniques employed to analyze the parent and hybrid materials, showing that surface silylation promoted by HN(SiHMe2)(2) is superior to titration with lithium alkyl LiCH2SiMe3.
DALTON TRANSACTIONS
(2022)
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, Multidisciplinary
Kavyasripriya K. Samudrala, Winn Huynh, Rick W. Dorn, Aaron J. Rossini, Matthew P. Conley
Summary: This study discovers an effective approach to prepare aluminum-silicon oxide catalysts with well-defined structures. Through experimental and theoretical calculations, it is demonstrated that the catalyst exhibits strong Lewis acidity and can react with organometallic compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Shiyu Zhen, Gong Zhang, Dongfang Cheng, Hui Gao, Lulu Li, Xiaoyun Lin, Zheyuan Ding, Zhi-Jian Zhao, Jinlong Gong
Summary: This paper presents a large-scale simulation to obtain realistic CuZn nanoparticle models and the atomic structure of active sites for C2+ products on CuZn catalysts in CO2ER. Two kinds of active sites, both facilitating C-C coupling, are identified and verified through subsequent calculations and experiments. This work provides a paradigm for the design of high-performance Cu-based catalysts and a general strategy to accurately identify the atomic structures of active sites in complex catalytic systems.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Materials Science, Multidisciplinary
Bruno Focassio, Gabriel R. Schleder, Felipe Crasto de Lima, Caio Lewenkopf, Adalberto Fazzio
Summary: Through simulations, it was found that amorphous Bi2Se3 has a reduced energy gap and its stability is influenced by defective environments. Additionally, topologically trivial surface states similar to standard helical topological states were identified in amorphous Bi2Se3.
Article
Biochemistry & Molecular Biology
Alexandra Primikyri, Georgios Papamokos, Themistoklis Venianakis, Marianna Sakka, Vassiliki G. Kontogianni, Ioannis P. Gerothanassis
Summary: This study investigates the structural basis of the interaction between artemisinin and human and bovine serum albumin using a combined strategy of experiments and calculations. The results suggest that artemisinin competes for binding sites with other drugs and interacts with bovine serum albumin in the presence of A. annua extract.
Article
Chemistry, Physical
Sander F. H. Lambregts, Ernst R. H. van Eck, Peter Ngene, Arno P. M. Kentgens
Summary: Complex metal hydride/oxide nanocomposites are potential solid-state electrolytes with high ionic conductivities. This study uses NMR spectroscopy to investigate the chemistry and dynamics of lithium borohydride confined in nanoporous silica, revealing the presence of a previously unknown silicon site in the nanocomposites. The thickness of the silica pore walls was also found to correlate with the fraction of lithium borohydride exhibiting fast dynamics. These findings provide insights into the interaction between complex metal hydrides and oxide hosts, which is crucial for understanding high ionic conductivity in these systems.
ACS APPLIED ENERGY MATERIALS
(2022)
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
Chemistry, Multidisciplinary
Mengting Jin, Manoj Ravi, Chen Lei, Christopher J. Heard, Federico Brivio, Zdenek Tosner, Lukas Grajciar, Jeroen A. van Bokhoven, Petr Nachtigall
Summary: Through experimental Al-27 NMR spectroscopy and computational data, this study reveals the detailed structure and formation mechanisms of zeolite framework-associated octahedral aluminium for the first time. The octahedral Lewis acid site becomes kinetically allowed and thermodynamically stable under wet conditions in the presence of multiple nearby Bronsted acid sites. The critical condition for the existence of such octahedral Lewis acid sites appears to be the availability of three protons.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Eleni Alexandri, Themistoklis Venianakis, Alexandra Primikyri, Georgios Papamokos, Ioannis P. P. Gerothanassis
Summary: Medium- and long-chain saturated and unsaturated free fatty acids can bind to human serum albumin (HSA), but the binding mode of polyunsaturated ?-3 fatty acids DHA and EPA in Sudlow's sites I and II of HSA is largely unknown. This study used STD, INPHARMA NMR techniques, and molecular docking calculations to investigate the binding mode of DHA and EPA in Sudlow's sites I and II of HSA. The results showed competitive binding modes of DHA and EPA with stereotypical ligands for Sudlow's sites I and II, and two orientations of DHA and EPA at the binding sites FA7 and FA4.
Article
Chemistry, Physical
Mao-Hua Zhang, Niloofar Hadaeghi, Sonja Egert, Hui Ding, Hongbin Zhang, Pedro B. Groszewicz, Gerd Buntkowsky, Andreas Klein, Jurij Koruza
Summary: In this study, a general approach was demonstrated to promote the reversibility of the unique electric-field-induced phase transition in antiferroelectric materials by modifying the material's local structure. A new composition based on NaNbO3, (1- x)NaNbO3-xSrSnO(3), was designed using first-principles calculations and experimental characterization. The results showed that the addition of SrSnO3 can enhance the stability of the antiferroelectric order and increase the energy storage density of the modified compositions.
CHEMISTRY OF MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Weiwei Cao, Ana Isabel Becerro, Victor Castaing, Xue Fang, Pierre Florian, Franck Fayon, Didier Zanghi, Emmanuel Veron, Alessio Zandona, Cecile Genevois, Michael J. Pitcher, Mathieu Allix
Summary: Y3Al5O12 (YAG) is a widely used phosphor host with optical properties controlled by chemical substitution at YO8 or AlO6/AlO4 sublattices, resulting in different emission wavelengths. Nonstoichiometric compositions of Y3+xAl5-xO12 have been synthesized, allowing for new emission wavelengths and activator ions coordination environments. The nonstoichiometric YAG:Ce3+ system has a different response to up-conversion luminescence compared to stoichiometric counterparts, while the down-conversion emission is weakly affected. This study also demonstrates the synthesis of nonstoichiometric garnet materials, opening possibilities for property tuning and new applications.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Review
Chemistry, Multidisciplinary
James Eills, Dmitry Budker, Silvia Cavagnero, Eduard Y. Chekmenev, Stuart J. Elliott, Sami Jannin, Anne Lesage, Joerg Matysik, Thomas Meersmann, Thomas Prisner, Jeffrey A. Reimer, Hanming Yang, Igor V. Koptyug
Summary: Magnetic resonance techniques, especially medical magnetic resonance imaging, are widely used in various scientific disciplines and practical applications. The development of spin hyperpolarization has greatly boosted both fundamental and applied magnetic resonance. Hyperpolarization techniques significantly enhance the signal intensity of magnetic resonance, overcoming its low sensitivity and opening up new possibilities for applications.
Article
Chemistry, Multidisciplinary
Dongfang Cheng, Ziyang Wei, Zisheng Zhang, Peter Broekmann, Anastassia N. Alexandrova, Philippe Sautet
Summary: The dynamic restructuring of Cu surfaces in electroreduction conditions was investigated using first-principles calculations and operando electrochemical scanning tunneling microscopy experiments. The restructuring of Cu(111) in acidic electrolyte was found to be potential- and pH-dependent. The strong adsorption of H atoms on the surface induced the formation of Cu adatoms, creating highly active sites for the hydrogen evolution reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Nina M. M. Sackers, Julia Nikodemus, Regina Palkovits, Philippe Sautet, Peter J. C. Hausoul
Summary: Despite previous kinetic studies, the mechanism of polyol hydrogenolysis on a Ru catalyst surface remains unclear. To gain insight into the mechanism, decomposition of methanol was investigated using a Ru/C catalyst and periodic DFT calculations on a Ru(0001) model surface. The results suggest that the surface is likely covered by hydrogen adsorbates during the experiments. On a clean Ru surface, a lower overall activation barrier is observed when fewer dehydrogenation steps occur before C-O bond cleavage in the substrate methanol. Transferring these findings to a hydrogen-saturated Ru surface, the pathway involving CH2O O-H formation and subsequent C-O cleavage is found to be the most favorable. This study highlights the significant influence of surface coverage on the activation barrier.
Article
Chemistry, Multidisciplinary
Paco Laveille, Pascal Mieville, Sourav Chatterjee, Elisa Clerc, Jean-Charles Cousty, Florian de Nanteuil, Erwin Lam, Edy Mariano, Adrian Ramirez, Urielle Randrianarisoa, Keyan Villat, Christophe Coperet, Nicolai Cramer
Summary: The Catalysis Hub - Swiss CAT+ is a funded infrastructure project jointly led by EPFL and ETHZ, which provides a unique integrated technology platform for automated and high-throughput experimentation in sustainable catalytic technologies. Divided into two hubs, EPFL focuses on homogeneous catalysis while ETHZ focuses on heterogeneous catalysis, the platform is open to both academic and private research groups. Through significant investment, both hubs have acquired high-end robotic platforms for synthesis, characterization, and testing of a large number of molecular and solid catalysts. The platforms are accompanied by a fully digitalized experimental workflow and a specific data management strategy to support closed-loop experimentation and advanced computational data analysis.
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
Isabelle Pianet, Anna Gutierrez Garcia-Moreno, Marie-Claire Savin, Nicolas Frerebeau, Julien Trebosc, Pierre Florian, M. Pilar Lapuente Mercadal
Summary: The study investigates the origin of dolomitic marble artefacts, especially those from quarries other than Cape-Vathy on Thasos Island. Various archaeometric techniques, including isotope analysis, petrography, cathodoluminescence, and elemental analysis, have been used to improve knowledge about provenance. In this study, solid-state nuclear magnetic resonance (NMR) spectroscopy is introduced to examine the molecular level of the material. Statistical analysis and Mg-25 NMR tests demonstrate the efficiency of a holistic approach for provenance determination and highlight the exploitation of dolomitic marble sources beyond the Greek Thasos source.
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
Chemistry, Multidisciplinary
Shyamapada Nandi, Asma Mansouri, Iurii Dovgaliuk, Philippe Boullay, Gilles Patriarche, Ieuan Cornu, Pierre Florian, Georges Mouchaham, Christian Serre
Summary: In this study, a novel cationic aluminum-based metal-organic framework (MOF) with high hydrolytic stability and selective CO2 adsorption was reported. Its crystal structure was determined by a combination of 3DED and high-resolution powder X-ray diffraction.
COMMUNICATIONS CHEMISTRY
(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.
Review
Chemistry, Multidisciplinary
Georges Menzildjian, Judith Schlagnitweit, Gilles Casano, Olivier Ouari, David Gajan, Anne Lesage
Summary: Dynamic Nuclear Polarization (DNP) is a method that enhances the sensitivity of solid-state NMR spectroscopy under Magic Angle Spinning (MAS), providing new analytical opportunities in chemistry and biology. DNP transfers polarization from unpaired electrons to nearby nuclei, and research in new polarizing sources for DNP solid-state NMR spectroscopy has led to significant breakthroughs, especially at high magnetic fields. This review discusses recent developments in this field, including the history of solid-state DNP, the development of dinitroxide radicals, and the design of metal complexes as polarizing sources.
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.
Article
Chemistry, Multidisciplinary
Simran Kumari, Anastassia N. Alexandrova, Philippe Sautet
Summary: In this study, the nature of zirconia on a copper inverse catalyst under CO2 hydrogenation to methanol conditions was comprehensively investigated using density functional theory calculations and the Grand Canonical Basin Hopping method. The research revealed significant changes in the active site induced by various reaction parameters, and suggested that the active site can be considered as a statistical ensemble of diverse structures.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Giyeong Son, Yichen Li, Anna V. Shneidman, Jae Hyo Han, Michael Aizenberg, Philippe Sautet, Joanna Aizenberg
Summary: Various materials have been developed to extend the function of light-absorbing devices to low-light or nighttime conditions. This study found that crystal surface engineering can be used as a powerful tool to optimize materials for electron storage.
CHEMISTRY OF MATERIALS
(2023)