Article
Chemistry, Physical
Mikalai A. Artsiusheuski, Jeroen A. van Bokhoven, Vitaly L. Sushkevich
Summary: The one-step valorization of natural gas is a challenge, and converting methane to methanol via chemical looping over copper-containing zeolites shows promise. Research has found that the Cu/Al ratio determines the selectivity of methane conversion by controlling the structure of the active copper sites.
Article
Chemistry, Physical
Mikalai A. Artsiusheuski, Jeroen A. van Bokhoven, Vitaly L. Sushkevich
Summary: The one-step valorization of natural gas is still a challenge, and converting methane to methanol via chemical looping over copper-containing zeolites seems to be a promising route. CuMFI is one of the earliest successful methods, but the structure of the active sites in CuMFI and the influence of copper loading and Si/Al ratio on the copper speciation are still not well understood. It has been found that the Cu/Al ratio determines the selectivity of methane conversion in CuMFI by controlling the structure of the active dicopper sites.
Article
Chemistry, Physical
Bin Zhang, Shuting Xiang, Anatoly Frenkel, Israel E. Wachs
Summary: The study investigates the increased activity of MoOx catalysts by surface modification and finds that specific anchoring surface hydroxyls control the number of active sites and the reaction rate of propylene metathesis, while the surface acid nature does not directly affect the number of active sites.
Article
Electrochemistry
Jeanet Conradie
Summary: A density functional theory study was conducted to determine the properties of a series of [Cu(phen)(2)](n+) complexes, which are favorable for use as dyes in DSSCs.
ELECTROCHIMICA ACTA
(2022)
Article
Chemistry, Inorganic & Nuclear
Rabina Pradhan, Vincent M. Groner, Kaylaa L. Gutman, Garrett E. Larson, Yuwei Kan, Qiang Zhang, Zachariah M. Heiden, Mark F. Roll, James G. Moberly, Kristopher Waynant
Summary: This study synthesized different methoxy regioisomers of ATF and evaluated their binding with CuI salts. The UV-Vis binding association studies showed a 2:1 binding association model for all species, with para-methoxy substitution exhibiting stronger binding than meta and ortho. Computed mechanisms suggested that metal salt dimers or ligand-metal salt-metal salt interactions contribute to the preference for the 2:1 binding model.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Spectroscopy
Sunita Prajapati, Subrata Jana
Summary: Recognition of metal ions in aqueous media is important for designing new supramolecular hosts. The binding behavior of three simple chalcones with variation in number of phenolic OH groups has been studied. The chalcones showed good binding capabilities towards metal ions in a CH3OH-H2O solvent system, with R1 and R2 exhibiting 2:1 mode of complexation and R3 forming 1:1 mode complexes using a carbonyl 'O' atom as the donor site.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Chemistry, Physical
Bin Zhang, Soe Lwin, Shuting Xiang, Anatoly Frenkel, Israel E. Wachs
Summary: The activity of catalysts supported by surface ReOx is controlled by the number and type of ligands on the oxide support, while the overall activity is influenced by the number of activated sites.
Article
Chemistry, Physical
V. Olijnyk, B. Dziuk
Summary: In the study, the behavior of Cu(II)/Cu(I) redox couple in CuX2-R2S system was explored under anhydrous and anaerobic conditions, showing that the Cl-Br substitution and the replacement of propyl group by allyl group were critical for tuning reduction potentials and trapping oxidation by-products. The trinuclear mixed-valence copper aggregates were found to play a crucial role in the evolution of the redox process. Moreover, crystal structures of intermediate and end product species were determined by single crystal X-ray diffraction, providing insights into the formation of sulfoxide and porous chiral networks.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Engineering, Electrical & Electronic
Hosam M. Gomaa, H. A. Saudi, I. S. Yahia, H. Y. Zahran
Summary: A new approach has been developed in this study to investigate the correlation between the optical and electrical conductivities of cerium sodium borate glasses. The amorphous nature of the samples was proven through X-ray diffraction analysis. The optical conductivity and dielectric parameters were fitted using Lorentz-Drude and Cole-Cole models, respectively. The study also analyzed the changes in different parameters with varying CeO2 content.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Chemistry, Analytical
Said Kounbach, Mokhtar Ben Embarek, Lhassane Mahi, Rachid Boulif, Redouane Beniazza, Rachid Benhida
Summary: This study focuses on the development of a potentiometric analytical method to analyze fluorosilicic acid produced in the chemical phosphate process. By conducting speciation studies and titration experiments, the concentration of fluorosilicic acid, as well as the amount of total acid and hydrofluoric acid, can be accurately determined.
MICROCHEMICAL JOURNAL
(2022)
Article
Chemistry, Physical
Aline R. M. Cruz, Luiz H. Vieira, Elisabete M. Assaf, Janaina F. Gomes, M. Assaf
Summary: Catalyst improvement is crucial in developing efficient fuel cell technologies. The promotion of the Cu/CeO2 system with Pt in the CO-PROX reaction was investigated. The PtCu/CeO2 catalysts prepared by impregnation showed high activity, while Cu/CeO2 and Pt/CeO2 were inactive. The addition of CO2-H2O to the feed stream improved the activity of PtCu/CeO2 catalysts. By using deactivation-resistant Pt sites, CO-PROX under H2O/CO2 feed stream at low temperatures can be effectively achieved.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Biochemistry & Molecular Biology
Malgorzata Smolilo-Utrata, Karolina A. Tarach, Katarzyna Samson, Mariusz Gackowski, Ewa Madej, Jozef Korecki, Grzegorz Mordarski, Michal Sliwa, Sebastian Jarczewski, Jerzy Podobinski, Piotr Kustrowski, Jerzy Datka, Dorota Rutkowska-Zbik, Kinga Gora-Marek
Summary: This study used various spectroscopic techniques to study the properties of vanadium species introduced into different zeolites, finding that basicity plays a critical role in the catalytic activity of the oxidative dehydrogenation of propane. Modifying zeolite through caustic treatment can adjust its basicity, aiding in the adsorption of vanadium species and increasing selectivity to propene.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
M. Pilar del Rio, B. Eva Villarroya, Jose A. Lopez, Ana M. M. Geer, Fernando J. J. Lahoz, Miguel A. A. Ciriano, Cristina Tejel
Summary: This study describes the synthesis of neutral and dicationic tetrametallic iridium chains connected by an iridium-iridium bond. The complexes exhibit fractional averaged oxidation states and electronic delocalization along the metallic chain. The absorption spectra of the complexes show characteristic bands that can be fine-tuned by varying the terminal capping ligands.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Wei Zhang, Hongfei Ma, Yalan Wang, Samuel Konrad Regli, Magnus Ronning, Kumar Ranjan Rout, Tigran Margossian, De Chen
Summary: The oxidation state of Cu species in ethylene oxychlorination is closely related to its catalytic performance. CuCl2 and CuCl are the primary active sites in the reduction and oxidation steps, respectively. The distribution of active sites is determined by the kinetic equilibrium of reduction, oxidation, and hydrochlorination rates. In this study, in situ X-ray absorption spectroscopy (XAS) and operando UV-vis-NIR spectroscopy were used to study the dynamic changes of Cu active sites in La-doped CuCl2/c-Al2O3 catalysts. A higher CuCl2 concentration significantly improves the activity, EDC selectivity, and stability. The presence of La enhances the reducibility of CuCl2 and modifies the catalytic performance rather than directly participating in the redox cycle. This study provides a deeper understanding of the role of active species and promoters in CuCl2/c-Al2O3 catalysts for ethylene oxychlorination.
JOURNAL OF CATALYSIS
(2023)
Article
Biochemistry & Molecular Biology
Nane A. Avagyan, Pavel S. Lemport, Mariia V. Evsiunina, Petr I. Matveev, Svetlana A. Aksenova, Yulia V. Nelyubina, Alexandr V. Yatsenko, Viktor A. Tafeenko, Vladimir G. Petrov, Yuri A. Ustynyuk, Xihe Bi, Valentine G. Nenajdenko
Summary: Three pyrrolidine-derived phenanthroline diamides were studied as ligands for lutetium trinitrate. The presence of halogen atoms in the structure of phenanthroline ligands has a significant impact on the coordination number of lutetium and the number of solvate water molecules. Fluorinated ligands showed higher efficiency based on the measured stability constants. Complexation with lutetium led to a shift in the F-19 NMR signal. The advantages of chlorinated and fluorinated pyrrolidine diamides in liquid-liquid extraction were demonstrated.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Physical
Yifan Sun, Ye Lv, Wei Li, Jinli Zhang, Yan Fu
Summary: In this study, PtRu electrocatalysts were fabricated on carbon paper via cyclic electrodeposition for the electrocatalytic hydrogenation (ECH) of phenol. The Pt3Ru3 catalyst exhibited excellent activity and stability for the conversion of phenol to cyclohexanol at ambient temperature and various current densities. The in situ Raman spectroscopy and kinetic study revealed the hydrogenation mechanism of phenol over Pt3Ru3 in acidic electrolyte, providing an effective electrochemical strategy for the facile construction of durable electrode materials and efficient phenol hydrogenation.
JOURNAL OF CATALYSIS
(2024)
Article
Chemistry, Physical
Amir Shahzad, Khezina Rafiq, Muhammad Zeeshan Abid, Naseem Ahmad Khan, Syed Shoaib Ahmad Shah, Raed H. Althomali, Abdul Rauf, Ejaz Hussain
Summary: Photocatalytic hydrogen production through water splitting is an effective method for meeting future energy demands. In this study, researchers synthesized a 1 % Ag2S/Cu2S co-doped CdZnS catalyst and found that it can produce hydrogen at a higher rate. The co-doping of Ag2S and Cu2S in the CdZnS catalyst showed a synergistic effect, with Ag2S promoting oxidation reactions and Cu2S promoting reduction reactions.
JOURNAL OF CATALYSIS
(2024)
