Article
Chemistry, Physical
Remi F. Andre, Gwenaelle Rousse, Capucine Sassoye, Maxim Avdeev, Benedikt Lassalle-Kaiser, Benoit Baptiste, Sophie Carenco
Summary: This article investigates the key compound of cerium oxide as a catalyst and identifies an intermediate phase of Ce-(IV) that forms in the presence of air. The crystal structure of this phase is proposed, and it is confirmed to be an observable intermediate in the synthesis of cerium dioxide.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Physical
Mauricio Lopez Luna, Janis Timoshenko, David Kordus, Clara Rettenmaier, See Wee Chee, Adam S. Hoffman, Simon R. Bare, Shamil Shaikhutdinov, Beatriz Roldan Cuenya
Summary: The study investigates the structural and chemical evolution of oxide-supported iron nanoparticles during the activation stages and the CO2 hydrogenation reaction, revealing the preferential formation of iron surface oxides under reaction conditions. The results highlight the important role played by the oxide support in the final structure and composition of nanosized catalysts.
Article
Nanoscience & Nanotechnology
Deok-Yong Cho, Ki-jeong Kim, Kug-Seung Lee, Michael Lubben, Shaochuan Chen, Ilia Valov
Summary: Thin layers inserted between a metal electrode and a solid electrolyte can modify the transport of mass and charge at interfaces and affect electrode reactions. Incorporating C films in functional materials can alter the host's chemical properties and device functionalities. Using X-ray spectroscopies, it was found that inserting graphene or ultrathin amorphous C layers in a Ta2O5/Ta system can tune its chemical and electronic structures, thereby fundamentally changing the resistive switching functionalities.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Cheng-Kuan Su, Szu-Yu Chen, Jen-Hsuan Chung, Guo-Chian Li, Brigitte Brandmair, Thomas Huthwelker, John L. Fulton, Camelia N. Borca, Shing-Jong Huang, Joseph Nagyvary, Hsiao-Han Tseng, Chih-Hui Chang, Dai-Ting Chung, Rafael Vescovi, Yi-Shiuan Tsai, Wenjie Cai, Bing-Jyun Lu, Jia-Wei Xu, Chia-Shuo Hsu, Jun-Jie Wu, Hao-Zhi Li, Yu-Kai Jheng, Sheng-Fong Lo, Hao Ming Chen, Yi-Ting Hsieh, Po-Wen Chung, Chien-Sheng Chen, Yuh-Chang Sun, Jerry Chun Chung Chan, Hwan-Ching Tai
Summary: The investigation revealed unnatural elemental compositions and oxidation patterns in Cremonese soundboards, suggesting possible artificial manipulation. Analyzing data and historical information allowed for deductions on the minerals added for wood preservation or acoustic tuning. Old masters conducted materials engineering experiments to create soundboards with unique properties.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Engineering, Environmental
Ian Byrnes, Lisa Magdalena Rossbach, Jakub Jaroszewicz, Daniel Grolimund, Dario Ferreira Sanchez, Miguel A. Gomez-Gonzalez, Gert Nuyts, Estela Reinoso-Maset, Koen Janssens, Brit Salbu, Dag Anders Brede, Ole Christian Lind
Summary: Micro- and nanoscopic X-ray techniques were used to investigate the relationship between uranium tissue distributions and adverse effects on the digestive tract of Daphnia magna. The study showed that exposure to uranium nanoparticles (UNPs) resulted in adverse morphological changes to the midgut and hepatic ceca, as well as abnormal intestinal epithelial cells. High-resolution nano-XRF identified U particulates throughout the midgut and within hepatic ceca cells, coinciding with tissue damages. These findings highlight the importance of disrupted intestinal function as a mode of acute U toxicity in D. magna.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Lucia Amidani, Gavin B. M. Vaughan, Tatiana V. Plakhova, Anna Yu. Romanchuk, Evgeny Gerber, Roman Svetogorov, Stephan Weiss, Yves Joly, Stepan N. Kalmykov, Kristina O. Kvashnina
Summary: Through the combination of HEXS and HERFD XANES analysis, the short- and medium-range order of chemically precipitated ThO2 NPs has been characterized for the first time, providing new insights into the structures of NPs at different stages of formation. The pair distribution function revealed a high concentration of ThO2 small units mixed with ThO2 NPs in the initial steps of formation, and drying promoted the recrystallization of the smallest units into more thermodynamically stable ThO2 NPs.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Shusaku Karasawa, Kamal Prasad Sharma, Takahiro Saida, Shigeya Naritsuka, Yuichi Haruyama, Toru Asaka, Takahiro Maruyama
Summary: In situ XAFS analysis revealed that the chemical states of catalyst particles during SWCNT growth are closely related to the metal properties.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Environmental Sciences
Nyekachi C. Adele, Bryne T. Ngwenya, Kate Heal, J. Frederick W. Mosselmans
Summary: Inoculation of soil or seeds with plant growth promoting bacteria can ameliorate metal toxicity to plants by changing metal speciation in plant tissues. The speciation changes, particularly an increase in organic acids and thiol complexes, were found significant between the rhizosphere and the root. This study suggests that changes in metal speciation may be driven by microbial metabolism or plant responses.
ENVIRONMENTAL POLLUTION
(2021)
Article
Chemistry, Inorganic & Nuclear
V. V. Popov, A. P. Menushenkov, A. A. Yastrebtsev, A. Yu Molokova, A. A. Pisarev, E. Khramov, Y. Zubavichus, I. Shchetinin, K. Ponkratov, N. A. Tsarenko, N. Ognevskaya
Summary: The crystal structure and morphology of hydrated molybdenum oxides particles obtained by acidic precipitation of different molybdates solutions were studied, showing that the acidity and temperature of the solution significantly affect the crystal structure and morphology of the products.
JOURNAL OF SOLID STATE CHEMISTRY
(2021)
Article
Chemistry, Physical
Espen Z. Eikeland, Hugo Silva, Lasse R. Jorgensen, Jonas Beyer, Toshiaki Ina, Henrik L. Hellstern, Christian Kallesoe, Leif H. Christensen, Bo B. Iversen
Summary: Adding Fe to PtPd nanoparticles on gamma-alumina increases catalytic activity due to increased Pt-Pd coordination induced microstrain during thermal aging. X-ray absorption spectroscopy confirms that Fe dopant atoms are incorporated into the alumina surface, fine tuning the electronic state and enhancing oxidation resistance to Pt.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Hassan Javed, Axel Knop-Gericke, Rik V. Mom
Summary: Potential spikes during start-up and shutdown of fuel cells cause platinum electrocatalyst degradation. In this study, XPS is used to investigate the oxidation states of platinum during fuel cell operation and it is found that a mixed surface oxide is formed at high potentials. The description of platinum oxidation is valid during transient conditions of fuel cell start-up and shutdown.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Weifeng Huang, Jianxin Kang, Tingwen Chen, Dawei Pang, Lihua Wang, Hang Wei, Changchun Yang, Dongfeng Zhang, Lin Guo
Summary: Nickel based magnetic nanocrystals have wide applications in magnetic and catalytic fields. Tunable magnetic properties of nickel can be achieved through non-magnetic doping or phase transformation. This study presents a way to control the magnetism of Au@Ni-carbide magnetic materials by adjusting the amount of carbon in the Ni layer, and provides solid evidence for the carbonation process from fcc-Ni to Ni X C instead of phase transformation to hcp-Ni. Further investigation reveals that the magnetism of the hybrids is mainly contributed from the residual fcc-Ni.
Review
Chemistry, Physical
Francisco Zaera
Summary: Catalysis in industrial chemical processes has long been studied through various spectroscopic techniques like vibrational and X-ray spectroscopies, allowing for a molecular-level understanding of catalytic mechanisms. These techniques help researchers explore the intricate details of catalytic processes and advancements in the field.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Physical
Yogesh Kumar, S. Tripathi, Mangla Nand, R. Jangir, V. Srihari, A. Das, R. Singh, U. Deshpande, S. N. Jha, A. Arya
Summary: This study investigated the effect of Nd doping on the structural, optical, and electronic properties of lanthanum monazite structure. Pure and Nd-doped LaPO4 powders were prepared and analyzed for their composition, oxidation states, crystal structure, and bandgaps. The results confirmed the successful substitution of Nd in the LaPO4 matrix and provided insights into the local structure using extended X-ray absorption fine structure analysis.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Review
Chemistry, Physical
George E. Cutsail, Serena DeBeer
Summary: X-ray spectroscopy plays a significant role in catalysis research by providing essential electronic and geometric structural information. The development of dedicated synchrotron-based X-ray emission spectrometers has expanded experimental capabilities, offering more detailed data. There is a continuous demand for conventional XAS applications and the integration with more advanced techniques.
Editorial Material
Chemistry, Physical
Johannes Lercher, Harold Kung, In-Sik Nam, Rafael Lucques, James Spivey
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Applied
Jan Folke, Kassioge Dembele, Frank Girgsdies, Huiqing Song, Rene Eckert, Stephan Reitmeier, Andreas Reitzmann, Robert Schloegl, Thomas Lunkenbein, Holger Ruland
Summary: Complementary bulk and local analytical techniques were used to investigate the effect of selected promoters on the catalytic performance of wuestite-based catalysts for ammonia synthesis. The results showed that the use of promoters had a positive effect and improved the catalytic performance.
Article
Engineering, Chemical
Verena B. Hoepfl, Teresa Schachtl, Yue Liu, Johannes A. Lercher
Summary: This study found that increasing the catalyst pellet size can reduce catalyst deactivation and increase the overall yield during its lifetime. This is due to limited mass transport in larger catalyst pellets, resulting in lower concentrations of butene at acid sites and suppressing the formation of heavy hydrocarbons that block active sites.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Chemistry, Physical
Alexander Wellmann, Lorenzo Grazia, Ricardo Bermejo-Deval, Maricruz Sanchez-Sanchez, Johannes A. Lercher
Summary: Promoters Cs+ and Sb4+ can affect the o-xylene oxidation pathways on TiO2 supported vanadium oxide catalysts. Sb4+ promotes the reaction by increasing the availability of oxygen for V site reoxidation at high temperatures, while Cs+ enhances V site reoxidation and increases the ratio of different types of oxygen on the surface.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Qiang Liu, Niklas Pfriem, Guanhua Cheng, Eszter Barath, Yue Liu, Johannes A. Lercher
Summary: The ionic environment inside microporous zeolites can significantly affect the catalytic turnover rates by modifying the chemical potential of the reactants and transition states. However, zeolites with high ionic strength seem to have a limit to the rate enhancement for the aqueous-phase dehydration of alcohols. This limitation is hypothesized to be caused by spatial constraints in the pores, such as size exclusion effects. This study demonstrates that the increase in turnover rate, the formation of a maximum, and the subsequent rate drop are intrinsic consequences of the increasingly dense ionic environment in zeolite.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Multidisciplinary Sciences
Guanhua Cheng, Wei Zhang, Andreas Jentys, Erika E. Ember, Oliver Y. Gutierrez, Yue Liu, Johannes A. Lercher
Summary: This study demonstrates the significant role of the self-established open circuit potential (OCP) in stabilizing cationic intermediates and transition states, as well as enhancing reaction rates in catalytic reactions.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Ruixue Zhao, Rachit Khare, Yang Zhang, Maricruz Sanchez-Sanchez, Ricardo Bermejo-Deval, Yue Liu, Johannes A. Lercher
Summary: Steric confinement in zeolites affects the catalytic conversion of alkanes. Silica species grafted near Bronsted acid sites in H-ZSM-5 zeolite enhance the binding of bases and increase the reaction rate of protolytic cracking of n-pentane with a lower activation energy. The presence of extra-framework silica leads to an earlier transition state and better stabilization of carbonium ions compared to extra-framework alumina.
Article
Multidisciplinary Sciences
Wei Zhang, Sungmin Kim, Lennart Wahl, Rachit Khare, Lillian Hale, Jianzhi Hu, Donald M. Camaioni, Oliver Y. Gutierrez, Yue Liu, Johannes A. Lercher
Summary: We propose a unique approach to selectively upcycle polyolefin waste by utilizing a highly ionic reaction environment, which increases polymer reactivity and reduces energy required for breaking carbon-carbon bonds. By catalyzing endothermic cleavage and exothermic alkylation reactions, we are able to convert polyethylene and polypropylene to liquid isoalkanes at temperatures below 100 degrees C. This process offers a high yield conversion of unprocessed postconsumer items into high-quality liquid alkanes.
Article
Chemistry, Physical
Yong Wang, Xiaofeng Chen, Hui Shi, Johannes A. Lercher
Summary: Metal oxides of group 4-6 elements are found to be active and stable catalysts for H2S reforming of methane, with dynamical binding of sulfur species (S*) to metal cations as the key active sites. Analysis of kinetic data and isotopic substitution effects reveals that S*-mediated C-H bond cleavage is the most plausible rate-limiting step common for all catalysts, with subtle yet essential differences in the thermodynamic stability of S* between 3d and 4d/5d catalysts.
Article
Chemistry, Applied
Feng Chen, Sungmin Kim, Dushyant Barpaga, John. L. L. Fulton, Radha Kishan Motkuri, Oliver. Y. Y. Gutierrez, Donald. M. M. Camaioni, Johannes. A. A. Lercher
Summary: Bronsted-acid sites are introduced on the ZrO2 nodes of UiO-66 MOFs via -OSO3H groups. These sites exhibit strong Bronsted acidity and are active for cyclohexanol and ethanol dehydration reactions in different phases. The activity of Bronsted acid sites at nodes is improved by increasing sulfur concentration, which leads to the formation of two interacting groups [(&mu(3)-OSO3H)(2)] through hydrogen bonding. The catalytic activity can be manipulated by functionalizing zirconia nodes of the MOF framework.
TOPICS IN CATALYSIS
(2023)
Article
Chemistry, Physical
Benjamin Yeh, Saumil Chheda, Jian Zheng, Julian Schmid, Laura Loebbert, Ricardo Bermejo-Deval, Oliver Y. Gutierrez, Johannes A. Lercher, Laura Gagliardi, Aditya Bhan
Summary: In this study, the steady state propylene oligomerization rates and selectivities were measured on Ni/UiO-66 metal organic framework (MOF), demonstrating the validity of the Cossee-Arlman mechanism. It was found that propylene dimerization reaction follows a first-order kinetics with respect to propylene pressure, and the selectivities are consistent with the selectivity expressions derived from the Cossee-Arlman mechanism.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Laura C. Meyer, Udishnu Sanyal, Kelsey A. Stoerzinger, Katherine Koh, John L. Fulton, Donald M. Camaioni, Oliver Y. Gutierrez, Johannes A. Lercher
Summary: In this study, the electrocatalytic hydrogenation (ECH) of aldehydes and ketones over carbon-supported Pd in the aqueous phase was investigated. The reaction mechanisms were proposed based on kinetic measurements and characterization of the catalyst. The rates of ECH and H-2 evolution reaction (HER) varied with the applied electric potential, which strongly depended on the organic substrate. The sorption of the organic compound and the rates of proton-coupled electron transfers influenced the kinetics of both ECH and HER.
Article
Chemistry, Physical
Lara Milakovic, Yue Liu, Eszter Barath, Johannes A. Lercher
Summary: This study reveals the impact of the tetragonal zirconia phase on octadecanol dehydration in zirconia supported tungstates catalysis, and finds that small concentrations of Pt can increase the acidity site concentration.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Rachit Khare, Roland Weindl, Andreas Jentys, Karsten Reuter, Hui Shi, Johannes A. Lercher
Summary: NaY zeolite-encapsulated Mo2S4 molybdenum sulfide clusters stabilize hydrogen as hydride binding to Mo atoms. Each cluster can activate only one hydrogen molecule under reaction conditions, suggesting that the entire cluster acts as one active site for hydrogenation.
Article
Chemistry, Multidisciplinary
Zhiying Fan, Lena Staiger, Karina Hemmer, Zheng Wang, Weijia Wang, Qianjie Xie, Lunjia Zhang, Alexander Urstoeger, Michael Schuster, Johannes A. Lercher, Mirza Cokoja, Roland A. Fischer
Summary: The embedding of metal nanoparticles in metal-organic frameworks (MOFs) is crucial in catalysis research, as it prevents agglomeration and allows for functionalization of the MOF matrix to optimize the chemical environment. In this study, Pd nanoparticles were incorporated into the MOF CuBTC by encapsulation, and the hydrophobicity was adjusted by using functionalized linkers. These modifications significantly improved the catalytic activity, suggesting that channel engineering is an efficient way to optimize metal@MOF catalysts.
CELL REPORTS PHYSICAL SCIENCE
(2022)