Article
Chemistry, Multidisciplinary
Youngho Kang, Sungwoo Kang, Seungwu Han
Summary: Based on density functional theory calculations, it was found that in transition metal- and nitrogen-codoped graphene, single Zn atoms do not serve as active sites for CO production in CO2 reduction reactions, while the nearest neighbor C atom (C-NN) exhibits high activity and the Zn atom enhances the catalytic activity of C-NN. The study also revealed that *COOH formation is favorable at the initial electrochemical step on the C-NN site, and each reaction step becomes downhill in energy at small applied potentials, elucidating the origin of the CO2 reduction activity.
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
Multidisciplinary Sciences
Terry Z. H. Gani, Zachariah J. Berkson, Ran Zhu, Jong Hun Kang, John R. Di Iorio, Ka Wing Chan, Daniel F. Consoli, Sohel K. Shaikh, Christophe Coperet, Yuriy Roman-Leshkov
Summary: The authors identify a dynamic site renewal and decay cycle, mediated by proton transfers involving proximal BrOnsted acidic OH groups, which operates concurrently with the Chauvin cycle and could address roadblocks associated with industrial metathesis processes. This cycle can be manipulated using small quantities of promoter olefins to drastically increase steady-state propylene metathesis rates, with negligible promoter consumption, showing potential applicability to other reactions. The increase in activity and reduction of operating temperature requirements were also observed on MoOx/SiO2 catalysts, indicating the broad scope of this strategy in addressing major challenges in industrial metathesis processes.
Review
Chemistry, Multidisciplinary
Xiaobo Zheng, Peng Li, Shixue Dou, Wenping Sun, Hongge Pan, Dingsheng Wang, Yadong Li
Summary: This review comprehensively summarizes the recent exciting progress on non-carbon-supported SACs and their applications in electrocatalytic reactions. Eight types of non-carbon-supported SACs are categorized to show their diversity, with detailed analysis of the anchoring and stabilization mechanisms. Advanced characterization techniques for identifying and monitoring the atomic structure of SACs are highlighted, along with discussions on their applications in electrochemical energy conversion.
ENERGY & ENVIRONMENTAL SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Jeffery L. White, Kuizhi Chen, Anya Zornes, Vy Nguyen, Bin Wang, Zhehong Gan, Steven P. Crossley
Summary: This study reveals the presence of at least two types of paired active sites in zeolite catalysts through NMR experiments, and finds that these paired sites play a crucial role in reactivity. Additionally, it is observed that synthetic and postsynthetic modifications affect the quantity and arrangement of these paired sites.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Muhua Chen, Weizhen Wang, Yuping Qiu, He Wen, Guangyao Li, Zhiqing Yang, Ping Wang
Summary: This study experimentally identified the active sites in HCHO oxidation over TiO2-supported Pt catalysts and revealed the cooperative mechanism involved.
Review
Chemistry, Multidisciplinary
Shaolong Zhang, Minchen Hou, Yanliang Zhai, Hongjie Liu, Dong Zhai, Youqi Zhu, Li Ma, Bin Wei, Jing Huang
Summary: Dual-Active-Sites Single-Atom catalysts (DASs SACs) are a type of catalysts with dual active sites, including single atomic active sites and other types of active sites. They exhibit excellent catalytic performance and have a wide range of applications. This review comprehensively describes the preparation methods, structural characteristics, and evaluations of DASs SACs in various applications, as well as discusses their unique catalytic mechanisms. The prospects and challenges of DASs SACs and their related applications are also highlighted.
Review
Multidisciplinary Sciences
Xue Yao, Ethan Halpren, Ye Zhou Liu, Chung Hsuan Shan, Zhi Wen Chen, Li Xin Chen, Chandra Veer Singh
Summary: Active components with suitable supports are commonly used in industrial catalysis, and the catalytic activity can be enhanced by reducing the size of the active component, leading to the development of single-atom catalysts (SACs). However, the activity improvement of SACs is hindered by the low loading of single atoms (SAs) due to their aggregation during preparation. Therefore, the focus should be shifted to investigate SACs with intrinsic SAs, which can prevent the aggregation of SAs and increase their loading to further enhance the activity. This review discusses SACs with external or intrinsic SAs and outlines the perspectives and challenges for obtaining high-loading SACs with intrinsic SAs.
Editorial Material
Chemistry, Physical
Lichen Liu, Avelino Corma
Summary: Identifying active sites in supported catalysts with isolated metal atoms and subnanometric clusters is challenging due to the difficulty in obtaining detailed structural information under reaction conditions. Limitations and pitfalls may be encountered, but suggestions can help overcome them.
Article
Chemistry, Physical
Bin Zhang, Israel E. Wachs
Summary: A series of supported ReOx catalysts were investigated to identify the unique surface anchoring sites on oxide supports responsible for activating the surface ReO4 sites for propylene metathesis. The specific oxide support was found to control the number of activated sites and propylene metathesis activity, revealing that the oxide support is a potent ligand for the surface ReOx sites.
Article
Chemistry, Physical
Jian Zheng, Laura Loebbert, Saumil Chheda, Navneet Khetrapal, Julian Schmid, Carlo Alberto Gaggioli, Benjamin Yeh, Ricardo Bermejo-Deval, Radha Kishan Motkuri, Mahalingam Balasubramanian, John L. Fulton, Oliver Y. Gutierrez, J. Ilja Siepmann, Matthew Neurock, Laura Gagliardi, Johannes A. Lercher
Summary: Homotopic sites are ideal for mechanistic studies and optimal control of catalytic transformations. Nickel cations in different environments show different selectivity in the reaction of 1-butene, and the reaction mechanism follows the Cossee-Arlman mechanism.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Thalita S. Galhardo, Adriano H. Braga, Bruno H. Arpini, Janos Szanyi, Renato Goncalves, Bruno F. Zornio, Caetano R. Miranda, Liane M. Rossi
Summary: Control of the selectivity of CO2 hydrogenation catalysts is a fundamental challenge. In this study, it was found that changing the surface of a common Ni catalyst can lead to high selectivity toward CO formation in CO2 hydrogenation processes, representing an important step towards high-added-value products.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Review
Chemistry, Multidisciplinary
Christopher Uyeda, Conner M. Farley
Summary: Multinuclear catalysts show unique abilities to cooperatively engage substrates, while binuclear catalysts provide new electronic configurations and covalent bonding to effectively address challenges not easily solved by single-metal systems. Novel ligands can stabilize metal-metal bonds, activate strong bonds, and have significant implications in catalytic reactions.
ACCOUNTS OF CHEMICAL RESEARCH
(2021)
Article
Multidisciplinary Sciences
Yuanyuan Li, Matthew Kottwitz, Joshua L. Vincent, Michael J. Enright, Zongyuan Liu, Lihua Zhang, Jiahao Huang, Sanjaya D. Senanayake, Wei-Chang D. Yang, Peter A. Crozier, Ralph G. Nuzzo, Anatoly Frenkel
Summary: This study reveals the dynamic characteristics of a Pt/CeO2 system for the water gas shift reaction, showing the formation and transformation of perimeter Pt-0-O vacancy-Ce3+ sites that regulate adsorbate behaviors and play a key role in the catalytic mechanism. The dynamic nature of these sites is crucial for understanding the reaction mechanism.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Dairong Liu, Linfei Li, Buddhika S. A. Gedara, Michael Trenary, Nan Jiang
Summary: Extensive research on ultrathin ferrous oxide (FeO) islands and films has significantly contributed to understanding their structural and catalytic properties. In this study, scanning tunneling microscopy (STM) was used to investigate the interaction of Pd and Pt with FeO grown on Au(111). The results demonstrate different metal affinities of FeO edges, with Pd preferentially growing on the Fe-terminated edge and Pt preferentially growing on the O-terminated edge, resulting in selectively blocked FeO edges. This study provides new insights into the edge reactivity of FeO/Au(111) and suggests a potential approach for controlling the selectivity of FeO catalysts.
MATERIALS CHEMISTRY FRONTIERS
(2023)
Article
Materials Science, Multidisciplinary
David W. Gardner, Jiaqi Li, Martin Kunz, Wei-Chih Liao, Chenhui Zhu, Carlo Carraro, Paulo J. M. Monteiro, Roya Maboudian
Summary: This article investigates the intergrain and intragrain interactions of calciumsilicate-hydrates (C-S-H), nanocrystalline forms of tobermorites, which control the long-term stress response of concrete. Through experiments, it is found that layer stacking disorder significantly increases in 11 angstrom tobermorite powder. Similar results are observed in nanocrystalline C-S-H powders, where layer stacking disorder (in the form of intragrain deformation) increases with low water content and large basal spacing.
Article
Chemistry, Multidisciplinary
Maximilian Krodel, Lorenz Abduly, Manouchehr Nadjafi, Agnieszka Kierzkowska, Alexander Yakimov, Alexander H. Bork, Felix Donat, Christophe Coperet, Paula M. Abdala, Christoph R. Mueller
Summary: Understanding the effects of different structural parameters of CaO-based CO2 sorbents on cyclic CO2 uptake is crucial for their advancement. Through mechanochemical activation, CaO-based sorbents with varying ratios of Na2CO3:CaCO3 were synthesized to investigate the impact of sodium species on the sorbents' structure, morphology, carbonation rate, and cyclic CO2 uptake. The addition of Na2CO3 in the range of 0.1-0.2 mol% significantly improved CO2 uptake by up to 80% after 10 cycles compared to untreated CaCO3, while higher Na2CO3 loadings (>0.3 mol%) led to a decrease of more than 40% in cyclic CO2 uptake due to accelerated deactivation caused by sintering and the presence of crystalline Na2Ca(CO3)(2) species with high mobility of Na.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Editorial Material
Chemistry, Multidisciplinary
Thomas R. Ward, Christophe Coperet
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, 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, Multidisciplinary
Seraphine B. X. Y. Zhang, Quentin Pessemesse, Zachariah J. Berkson, Alexander P. Van Bavel, Andrew D. Horton, Pierre-Adrien Payard, Christophe Coperet
Summary: Li/MgO is a prototypical material for oxidative coupling of methane (OCM) with high C-2 selectivity. This study demonstrates that Li/MgO is also an effective catalyst for non-oxidative coupling of methane (NOCM). The presence of Li favors the formation of magnesium acetylide (MgC2), which promotes C-C bond formation and enhances C-2 selectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
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
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
Lukas Rochlitz, Jorg W. A. Fischer, Quentin Pessemesse, Adam H. Clark, Anton Ashuiev, Daniel Klose, Pierre-Adrien Payard, Gunnar Jeschke, Christophe Coperet
Summary: This study investigates the effect of Ti doping on the catalytic performance of Pt and PtZn materials in propane dehydrogenation. The results show that Ti-doping significantly changes the electronic structure of nanoparticles and improves the stability of the materials.
Article
Chemistry, Multidisciplinary
Christian Ehinger, Xiaoyu Zhou, Max Candrian, Scott R. Docherty, Stephan Pollitt, Christophe Coperet
Summary: The synthesis of well-defined materials as model systems for catalysis and related fields plays a crucial role in understanding catalytic processes at a molecular level. Organometallic precursors have been developed to produce monodispersed supported nanoparticles, nanocrystals, and films. A new family of precursors based on group 10 metals has been discovered, which can generate small and monodispersed nanoparticles on metal oxides. These precursors show potential for synthesizing bimetallic catalyst materials and have been demonstrated for hydrogenation of CO2 to methanol.
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.
Article
Chemistry, Physical
Zixuan Chen, Alexander I. Serykh, Agnieszka Kierzkowska, David Gajan, Scott R. Docherty, Alexander V. Yakimov, Paula M. Abdala, Christophe Coperet, Pierre Florian, Alexey Fedorov, Christoph R. Mueller
Summary: In this study, we utilized atomic layer deposition to engineer a model PDH catalyst and found that the structural dynamics of surface sites vary with the degree of hydroxylation. The high-performance PDH catalyst possesses isolated tetracoordinate Ga-[4]((4Si)) sites.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
