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
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
Marc Ziemba, Jakob Weyel, Christian Hess
Summary: The research emphasizes the importance of combining different techniques to address the redox properties and intermediate dynamics. By analyzing the ceria morphologies to study the influence of surface termination on catalyst systems. The results suggest that the LT-WGS reaction over Cu/CeO2 catalysts is mainly based on a redox mechanism.
Article
Materials Science, Ceramics
Shagun Monga, Neeraj Sharma, Navina Mehan, Yogendra Kumar Mishra, Arun Singh
Summary: This study compares the structural and optical properties of PZT materials prepared by different methods, showing significant differences in bandgap values between the two samples.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Physical
Sebastian Cisneros, Shilong Chen, Thomas Diemant, Joachim Bansmann, Ali M. Abdel-Mageed, Michael Goepel, Sine E. Olesen, Eike S. Welter, Magdalena Parlinska-Wojtan, Roger Glaeser, Ib Chorkendorff, R. Juergen Behm
Summary: In this study, four different Ru/TiO2 catalysts were prepared and examined to investigate the impact of SiO2 content on the catalysts' performance in selective CO methanation. The results showed a volcano-shaped dependence of methane formation activity on SiO2 content, with the maximum activity observed at 4-8 wt.%. Additionally, weaker CO adsorption strength was found in the most active catalysts, indicating a complex combination of different effects contributing to the higher activity and lower CO adsorption strength.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Engineering, Environmental
Anqi Guo, Kunpeng Xie, Huarong Lei, Valentina Rizzotto, Limin Chen, Mingli Fu, Peirong Chen, Yue Peng, Daiqi Ye, Ulrich Simon
Summary: Cu-SSZ-13 catalyst was found to be deactivated by phosphorus poisoning in NH3-SCR reactions, leading to both loss of Cu active sites and restricted dynamic motion of Cu species. This inhibition significantly affects the redox cycling of Cu sites, especially the formation of key dimeric Cu intermediates, ultimately resulting in decreased NH3-SCR activity at low temperatures.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Sara Gomez, Natalia Rojas-Valencia, Tommaso Giovannini, Albeiro Restrepo, Chiara Cappelli
Summary: We explore the potential of resonance Raman spectroscopy for detecting ibuprofen in diluted aqueous solutions. By utilizing a fully polarizable quantum mechanics/molecular mechanics (QM/MM) approach coupled with molecular dynamics (MD) to account for the dynamic aspects of solvation, we demonstrate that selectively enhancing the Raman signal associated with the C-C stretching mode in the ring can facilitate the recognition of ibuprofen in water samples.
Article
Biochemistry & Molecular Biology
Hubert Fuks, Pawel Kochmanski, Elzbieta Tomaszewicz
Summary: New Gd3+- and Mn2+-co-doped calcium molybdato-tungstates were successfully synthesized using high-temperature solid-state reaction method and combustion route. The obtained ceramic materials have scheelite-type structure and show significant antiferromagnetic interactions. Spectroscopic and SEM studies were conducted to analyze the properties and morphology of the powders.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Spectroscopy
Chen Lu, Panpan Chen, Hao Sheng, Cunlei Li, Jingang Wang
Summary: In this work, the properties of absorption spectrum, electronic circular dichroism (ECD) spectrum, and Raman spectrum of infinitene (monomer and dimer) with double helical structure are theoretically studied. The electronic excitation properties, electromagnetic interaction mechanism, response to different wavelengths of excitation light, electron delocalization degree, magnetic response intensity, and interaction with the external environment are investigated. The inter-molecular interactions in the dimer are also studied.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Chemistry, Physical
Guangyan Xu, Yu Zhang, Jingguo Lin, Yibao Wang, Xiaoyan Shi, Yunbo Yu, Hong He
Summary: This study investigated the mechanism of ammonia selective catalytic oxidation (NH3-SCO) on Ag/Al2O3 catalysts using operando spectroscopy. The results showed that silver nanoparticles are the active sites for NH3 oxidation, while silver cations are inert in this reaction. The NH3-SCO reaction on 10 wt % Ag/Al2O3 could be divided into three regions, and the reaction pathway is closely related to oxygen activation on the silver nanoparticles.
Article
Chemistry, Physical
Clesia C. Nascentes, Ivette Aguilar, Guzman Gil-Ramirez, Jose Gonzalez-Rodriguez
Summary: The electropolymerization of metallo-octaethylporphyrins was studied and characterized using UV-Vis and Raman spectroscopies. The CuOEP-modified electrode showed excellent performance for the analysis of phenobarbital in antiepileptic treatments.
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
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
Food Science & Technology
Dmitrii Pankin, Anastasia Povolotckaia, Eugene Borisov, Alexey Povolotskiy, Sergey Borzenko, Anatoly Gulyaev, Stanislav Gerasimenko, Alexey Dorochov, Viktor Khamuev, Maksim Moskovskiy
Summary: Wheat has been crucial in human agriculture for centuries, and the increasing production of processed wheat products necessitates laboratory studies for quality control, including the detection of fungal diseases. This study utilized spectroscopic methods to investigate ergot-infected wheat samples, and chemometric analysis was employed to identify the most specific spectral ranges.
Article
Nanoscience & Nanotechnology
Yang Liu, Maichong Xie, Nicholas Marcella, Alexandre C. Foucher, Eric A. Stach, Marc R. Knecht, Anatoly Frenkel
Summary: In this research, an artificial neural network was trained to recognize the partial coordination numbers in AuPt nanoparticles synthesized with peptide templating, and combined with scanning transmission electron microscopy analysis, unique details of the catalytic system's heterogeneity were revealed. The proposed method based on enhanced Z-contrast of metal species will have implications for compositional studies of bimetallic nanoparticles.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Physical
Haodong Wang, Ning Rui, Sanjaya D. Senanayake, Lihua Zhang, Yuanyuan Li, Anatoly Frenkel
Summary: This study successfully created and controlled unique sites for Pt SACs on CeO2 support by designing anchoring sites. By changing the Pt weight loading, the placement of Pt atoms on the mixed oxide surface can be tuned.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Lior Asor, Jing Liu, Shuting Xiang, Nir Tessler, Anatoly I. Frenkel, Uri Banin
Summary: Doped heavy metal-free III-V semiconductor nanocrystal quantum dots (QDs) have attracted great interest for both their fundamental doping characteristics and their applicability in p-n homojunction devices. In this study, p-type doping of InAs NCs was achieved through the use of Zn, allowing for control over the charge carrier type in InAs QDs field effect transistors. X-ray absorption spectroscopy analysis confirmed substitutional doping by Zn2+ replacing In3+. Surface passivation by Zn was also observed, leading to enhanced near infrared photoluminescence. This research paves the way for the fabrication of optoelectronic devices active in the short-wave infrared region using heavy-metal free nanocrystal building blocks.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Bin Zhang, Michael E. Ford, Eli Ream, Israel E. Wachs
Summary: A series of supported MoOx catalysts on different oxide supports were synthesized and characterized. The results show that the oxide supports have a significant influence on the activation and surface chemistry of MoOx sites, which are controlled by the type and number of surface hydroxyls.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Alexandre C. Foucher, Daniel J. Rosen, Shengsong Yang, Dario Ferreira Sanchez, Ilia Sadykov, Daniel Grolimund, Anatoly I. Frenkel, Christopher B. Murray, Eric A. Stach
Summary: This article presents the characterization and applications of core-shell Cu-Ir nanocatalysts in oxygen reduction reaction and oxygen evolution reaction. By controlling the thickness of the Ir shell, the Cu core can be removed via oxidation to obtain Ir shells, which determine the stability and optimization of the precious metals. Through in situ scanning transmission electron microscopy, the remarkable stability of the Ir shells at high temperatures under oxidative and reductive environments is demonstrated. Electrochemical measurements show that the Cu-Ir nanocatalysts exhibit promising activity and stability compared to a commercial catalyst. Thin Ir shells result in higher surface area per gram of Ir and higher activity, while thicker Ir shells are more stable and exhibit excellent electrochemical properties in aqueous and alkaline environments. Consequently, Ir nanoshells are considered interesting candidates for reducing the cost of catalysis and improving chemical performance in fuel cells.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Physical
Junying Li, Peipei Huang, Facheng Guo, Jiahao Huang, Shuting Xiang, Ke Yang, N. Aaron Deskins, Victor S. Batista, Gonghu Li, Anatoly I. Frenkel
Summary: In this study, the structure of a hybrid photocatalyst consisting of a macrocyclic cobalt complex deposited on graphitic carbon nitride (C3N4) was investigated using XANES, EXAFS spectroscopies, DFT, and computational XANES modeling. The results revealed that the cobalt complex binds to C3N4 through surface OH or NH2 groups. By refining the local geometry and binding sites, this research provides an important benchmark for modeling a large class of molecular catalysts and enables further improvement through chemometrics-based approaches and machine learning methods of XANES data analysis.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Alexandre C. Foucher, Shengsong Yang, Daniel J. Rosen, Renjing Huang, Jun Beom Pyo, Ohhun Kwon, Cameron J. Owen, Dario Ferreira Sanchez, Ilia I. Sadykov, Daniel Grolimund, Boris Kozinsky, Anatoly I. Frenkel, Raymond J. Gorte, Christopher B. Murray, Eric A. Stach
Summary: We developed a method to synthesize highly mono-disperse Cu-Pt alloy nanoparticles. These nanoparticles exhibited stability under redox conditions and displayed promising activity and stability for CO oxidation. The incorporation of Pt with Cu did not lead to rapid deactivation and degradation of the material as seen with other bimetallic systems. This work provides a synthesis route to control the design of Cu-Pt nanostructures and highlights the potential of these alloys for heterogeneous catalysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Instruments & Instrumentation
Junying Li, Prahlad K. Routh, Yuanyuan Li, Anna Plonka, Evgeniy Makagon, Igor Lubomirsky, Anatoly Frenkel
Summary: Electro-chemo-mechanical (ECM) coupling refers to mechanical deformation due to electrochemically driven compositional change in a solid. Recently, a stable ECM actuator producing small displacements at room temperature was reported. The investigation of the Ti and Ce ions in Ti-GDC nanocomposites showed that Ti atoms form a cerium titanate or segregate into a TiO2 anatase-like phase depending on the Ti concentration. The transition region with Ti(IV) concentration between 19% and 57% is proposed to be the most advantageous for developing ECM-active materials.
JOURNAL OF SYNCHROTRON RADIATION
(2023)
Article
Nanoscience & Nanotechnology
J. L. Hart, A. C. Lang, Y. Li, S. Shahrezaei, D. D. Alix-Williams, M. L. Falk, S. N. Mathaudhu, A. I. Frenkel, M. L. Taheri
Summary: Short range order (SRO) is crucial for determining the performance of engineering materials, but accurate characterization with high spatial resolution is often experimentally inaccessible. In this study, SRO is locally quantified using scanning transmission electron microscopy with extended energy loss fine structure analysis. A novel instrumentation enables electron energy loss spectroscopy at energies conventionally achievable only with a synchrotron. This technique allows for quantitative analysis of local coordination environments and has been successfully applied to investigate a multicomponent metallic glass nanolaminate.
MATERIALS TODAY NANO
(2023)
Article
Chemistry, Multidisciplinary
Nathaniel Hurley, Michael Gallagher, Christopher Koenigsmann, Elena Stephanie, Monireh Davoudi, Anna M. Plonka, Haodong Wang, Lihua Zhang, Anatoly I. Frenkel, Stanislaus S. Wong
Summary: In this study, ultrathin nanowires of pure Pt, Pt99Ni1, Pt9Ni1, and Pt7Ni3 were successfully synthesized using a modified room-temperature soft-template method. It was found that the Pt7Ni3 samples exhibited the best performance in both methanol and ethanol oxidation reactions, while pre-treating Pt9Ni1 and Pt7Ni3 under a reducing atmosphere significantly improved the CO2 formation. The analysis of the extended x-ray adsorption fine structure (EXAFS) spectroscopy data indicated the presence of partial alloying and segregation of Pt and Ni within the nanowires.
Article
Chemistry, Multidisciplinary
Haodong Wang, Ryuichi Shimogawa, Lihua Zhang, Lu Ma, Steven N. Ehrlich, Nebojsa Marinkovic, Yuanyuan Li, Anatoly I. Frenkel
Summary: Single-atom catalysts are sensitive to external conditions, and tracking their structural evolution can identify active species and active sites. The migration of platinum nanoparticles affects catalytic activity.
COMMUNICATIONS CHEMISTRY
(2023)
Article
Chemistry, Physical
Scott C. McGuire, Nathaniel R. Hurley, Michael G. Gallagher, Lihua Zhang, Anatoly I. Frenkel, Stanislaus S. Wong
Summary: In the development of novel fuel cell catalysts, we have synthesized ultrathin nanowires and spoke-like dendritic clusters. Analysis shows that the elements tend to segregate into clusters, and the specific activity values of the samples in methanol oxidation reaction correlate with their chemical composition and reaction process.
Article
Multidisciplinary Sciences
Maxim Varenik, Boyuan Xu, Junying Li, Elad Gaver, Ellen Wachtel, David Ehre, Prahlad K. Routh, Sergey Khodorov, Anatoly I. Frenkel, Yue Qi, Igor Lubomirsky
Summary: In this study, a low relative permittivity ceramic material ZrxCe1-xO2 with electromechanical properties comparable to the best performing electrostrictors was discovered. The electromechanical properties of ZrxCe1-xO2 are enabled by elastic dipoles formed under an applied anisotropic electric field, which distinguishes it from other materials.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yuanyuan Li, Haodong Wang, Haohong Song, Ning Rui, Matthew Kottwitz, Sanjaya D. Senanayake, Ralph G. Nuzzo, Zili Wu, De-en Jiang, Anatoly I. Frenkel
Summary: This study successfully improved the activity of CO oxidation by designing Pt single atom catalysts supported on Gd-doped ceria. The results showed that a new Pt single atom site formed under CO pretreatment at elevated temperatures can significantly reduce the energy barrier of CO oxidation. The reactivity and reaction mechanism of the catalyst can be tuned by changing the local electronic and atomic structure of the Pt single atom through Gd doping.
Article
Materials Science, Multidisciplinary
Ingrid J. Paredes, Amani M. Ebrahim, Rito Yanagi, Anna M. Plonka, Shuzhen Chen, Hanlu Xia, Scott Lee, Mersal Khwaja, Haripriya Kannan, Ajay Singh, Sooyeon Hwang, Anatoly I. Frenkel, Ayaskanta Sahu
Summary: The chemical versatility and rich phase behavior of tin phosphides have attracted researchers' interest for various applications. However, there are few viable methods to obtain high-quality and phase-controlled tin phosphides. In this study, we demonstrated that inexpensive and commercially available aminophosphines can be used to synthesize different phases of tin phosphides. We manipulated various factors to obtain phase-pure Sn3P4, SnP, and Sn4P3 nanocrystals. The phase purity was confirmed by X-ray diffraction and transmission electron microscopy.
MATERIALS ADVANCES
(2023)
