Article
Chemistry, Physical
Johannes Zeininger, Philipp Winkler, Maximilian Raab, Yuri Suchorski, Mauricio J. Prieto, Liviu C. Tanase, Lucas de Souza Caldas, Aarti Tiwari, Thomas Schmidt, Michael Stoger-Pollach, Andreas Steiger-Thirsfeld, Beatriz Roldan Cuenya, Guenther Rupprechter
Summary: In this study, spatial-temporal nonuniformities in H-2 oxidation on individual Rh(hkl) domains of a polycrystalline Rh foil were investigated using PEEM, XPEEM, and LEEM. The latter two techniques were used for in situ correlative microscopy, which provided higher lateral resolution and enabled the detection of island-mediated oxygen front propagation during kinetic transitions. The origin of this phenomenon was rationalized through model calculations based on a hybrid approach of microkinetic modeling and Monte Carlo simulations.
Article
Chemistry, Physical
Philipp Winkler, Maximilian Raab, Johannes Zeininger, Lea M. Rois, Yuri Suchorski, Michael Stoeger-Pollach, Matteo Amati, Rahul Parmar, Luca Gregoratti, Guenther Rupprechter
Summary: The catalytic behavior of Rh particles supported by different materials (Rh, Au, and ZrO2) in H-2 oxidation was investigated using photoemission electron microscopy (PEEM) and scanning photoemission electron microscopy (SPEM). Different catalytic performances were observed depending on the support and Rh particle size, with oscillations ranging from particle size-independent to fully inhibited. The experimental observations were supported by micro-kinetic simulations, which revealed the importance of hydrogen adsorption and oxygen binding in the catalytic process. This study highlights the significance of correlative in situ surface microscopy in understanding the relationship between local structure, composition, and catalytic performance.
Article
Chemistry, Physical
A. Kumari, W. W. Tjiu, Z. Aabdin, J. Roy, V. K. Verma, A. Kandasami, V. R. Singh
Summary: In this study, the effects of Co-doping and high-temperature annealing on the structural, optical, and electronic characteristics of TiO2 nanoparticles were investigated. The results showed that Co-doping and annealing can affect the grain size, phase composition, and electronic states of the nanoparticles. These findings are significant for improving the performance of TiO2 nanoparticles.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Kirill A. Bokai, Viktor O. Shevelev, Dmitry Marchenko, Anna A. Makarova, Vladimir Yu Mikhailovskii, Alexei A. Zakharov, Oleg Yu Vilkov, Maxim Krivenkov, Denis V. Vyalikh, Dmitry Yu Usachov
Summary: Intercalation of oxygen can facilitate the detection of grain boundaries in polycrystalline graphene, providing insights into their morphology, and enabling visualization through various electron microscopy methods.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Tzuriel S. Metzger, Reema Siam, Yuval Kolodny, Naama Goren, Nir Sukenik, Shira Yochelis, Raed Abu-Reziq, David Avnir, Yossi Paltiel
Summary: This study utilizes the chiral induced spin selectivity (CISS) effect to form chiral centers in catalytic reactions, demonstrating that the directionality of electron spin can break enantiomeric symmetry and enable asymmetric catalysis without the need for chiral reagents, solvents, or catalysts.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Shuai Zu, Quan Sun, En Cao, Tomoya Oshikiri, Hiroaki Misawa
Summary: By studying gold nanorods, the spatiotemporal origin of plasmonic chiroptical responses was revealed, promoting a full understanding of the ultrafast chiral origin in complex nanostructures. This research opens a way to design chiroptical nanophotonic devices for spatiotemporal control of chiral light-matter interactions.
Review
Chemistry, Inorganic & Nuclear
Nabakrushna Behera, Sipun Sethi
Summary: Uranyl catalysis, with the key species UO22+ ion, is of increasing significance in current research due to its stable molecular component and ecological importance. The electronic non-rigidity of uranium center and its kinetic lability in coordination states are key features contributing to the development in its catalytic reactivity profiles. The review explores promising uranyl(VI) catalytic systems in literature for the last two decades, including discussions on both homometallic uranyl catalysis and heterometallic uranyl catalysis, and comparisons with transition metal systems.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Tomoya Oshikiri, Quan Sun, Hiroki Yamada, Shuai Zu, Keiji Sasaki, Hiroaki Misawa
Summary: The study examines the chiral near-field intensity distribution on achiral gold nanorectangular structures under circularly polarized light, attributing the extrinsic chirality to the interference between two plasmonic modes. The intensity and phase angle of each mode under linearly polarized light are critical factors for the generation of extrinsic chirality in the near-field intensity distribution.
Article
Physics, Applied
Yang Zhou, Peng Zhang
Summary: This study investigates photoelectron emission from metal surfaces with laser wavelengths ranging from 200 to 1200 nm using a quantum model. It shows that non-equilibrium electron heating from intense sub-picosecond laser pulses can nonlinearly increase quantum efficiency, which is strongest when the cathode work function is a multiple of the laser photon energy. By reproducing previous experimental results, the quantum model with laser heating effects validates the importance of laser heating in electron emission mechanisms.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Multidisciplinary
Chun-Lai Fu, Zhen-Long Zhao, Bo-Yu Ji, Xiao-Wei Song, Peng Lang, Jing-Quan Lin
Summary: In this work, the improvement of near-field imaging of surface plasmon polaritons (SPPs) is demonstrated by comparing the visibility under different laser excitations. The underlying mechanism for the improved visibility is revealed, and the influence of laser polarization direction on the SPPs is shown.
Article
Chemistry, Applied
Fan Wu, Lei He, Wen-Cui Li, Rao Lu, Yang Wang, An-Hui Lu
Summary: In this study, a hexagonal boron nitride (BN) support with CuO modification was used to prepare highly dispersed Au catalysts, which exhibited excellent CO oxidation activity. The electron transfer between Au and Cu species on the CuO-modified BN surface favors the stabilization of highly dispersed Au nanoparticles and enhances CO adsorption, leading to improved catalytic performance. The results demonstrate that thermally stable and conductive CuO-modified BN is an excellent support for the preparation of highly dispersed and stable Au catalysts.
CHINESE JOURNAL OF CATALYSIS
(2021)
Review
Chemistry, Multidisciplinary
Si Woo Lee
Summary: Catalysis is enhanced by electron transfer between catalyst surface and reaction intermediate. Charge transfer in metal-oxide systems is crucial for catalytic performance. This review focuses on the detection of hot electrons in catalytic reactions and the relationship between electron transfer and reactivity. Coupling a catalytic nanodiode with metal-oxide heterogeneous catalysts allows studying the dynamics of hot electrons on metal surfaces.
TRENDS IN CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Yinyao Chen, Shuai Tang, Yan Shen, Huanjun Chen, Shaozhi Deng
Summary: This study proposes a photo-electric co-excited scheme to drive a tungsten needle nano-cold cathode, which exhibits low energy spread and high brightness electron emission performance that can be tuned by optical frequency and polarization. This research provides a choice to achieve tunable, miniaturized, and integrated vacuum micro- and nano-electronic devices.
Article
Thermodynamics
Xi Zhuo Jiang, Kai Hong Luo
Summary: This study combines ReaxFF and eFF MD simulations to investigate the influence of electric fields on ethanol oxidation reactions at atomic and subatomic scales. The results show that the electric field affects different stages of the reaction process in different ways, influencing reaction rates and pathways, as well as electron energy levels, providing unprecedented insights into field-assisted combustion systems design.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Chemistry, Multidisciplinary
Wei Liu, Haoran Yu, Yaolong Li, Aiqin Hu, Ju Wang, Guowei Lu, Xiaofang Li, Hong Yang, Lun Dai, Shufeng Wang, Qihuang Gong
Summary: For versatile lead-halide perovskite materials, trap states in both bulk and surface significantly affect optoelectronic behaviors and performance. Utilizing femtosecond pump-probe technique combined with PEEM, shallow and deep trap states were identified within a CsPbBr3 single-crystal microplate. The study revealed a high-defect tolerance to shallow traps within the microplate, while surface dynamics were dominated by deep traps. The ultrafast PEEM provided insights into fast electron transfer and accumulation of surface trap states, highlighting the importance of surface optimization for excellent electronic properties of perovskite materials.
Article
Chemistry, Applied
I. Lopez-Hernandez, V. Truttmann, N. Barrabes, G. Rupprechter, F. Rey, J. Mengual, A. E. Palomares
Summary: Catalysts based on gold nanoclusters supported by different materials have shown excellent selectivity in the semi-hydrogenation of phenylacetylene to styrene. The interaction between the gold nanoclusters and the support material plays a crucial role in determining the activity and selectivity. Basic support materials enhance both the activity and selectivity.
Article
Chemistry, Physical
Vera Truttmann, Hedda Drexler, Michael Stoeger-Pollach, Tokuhisa Kawawaki, Yuichi Negishi, Noelia Barrabes, Guenther Rupprechter
Summary: This study investigates the catalytic activity of ceria supported Au nanoclusters with different ligands (thiolates, phosphines, and a mixture) in CO oxidation reaction. The results show that thiolate-protected Au-25/CeO2 exhibits significantly higher CO conversion after activation at 250 degrees C compared to cluster catalysts with phosphine ligands. It was also found that the phosphine ligands decompose and expose the free Au surface, but temperatures higher than 250 degrees C are needed for their efficient removal from the catalyst system. Furthermore, the residues on the support have a greater influence on reactivity than the gold particle size.
Article
Chemistry, Physical
Noelia Barrabes, Jon Ostolaza, Sarah Reindl, Martin Maehr, Florian Schrenk, Hedda Drexler, Christoph Rameshan, Wojciech Olszewski, Guenther Rupprechter
Summary: Co-doped Au-25 nanoclusters with different numbers of doping atoms were synthesized and supported on CeO2 for catalytic CO oxidation. The catalytic activity was enhanced compared to pure Au-25 nanoclusters, with different performance depending on the number of Co atoms. XAFS, DRIFTS, and XPS studies revealed the evolution of doped Au clusters into CoAu nanoalloys with well-distributed Co atoms. Understanding the dynamics of doped nanoclusters on supports is crucial for the future development and application of bimetallic nanocluster catalysts.
FARADAY DISCUSSIONS
(2023)
Article
Chemistry, Physical
Qaisar Maqbool, Nevzat Yigit, Michael Stoeger-Pollach, Maria Letizia Ruello, Francesca Tittarelli, Guenther Rupprechter
Summary: By employing spectroscopy of working sensors, we have uncovered a new sensing mechanism that involves reversible physisorption and irreversible chemisorption of methanol, as well as surface electrochemical reactions forming CO2 and H2O resulting in electron/O-2 depletion and restoration.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Verena Pramhaas, Holger Unterhalt, Hans-Joachim Freund, Guenther Rupprechter
Summary: The surface structure and shape of oxide-supported metal nanoparticles can be determined using polarization-dependent sum-frequency-generation (SFG) spectroscopy. This technique reveals the average surface structure and shape of the nanoparticles and can be used to monitor particle restructuring in situ. It has the potential to be a valuable tool for operando catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Thanaree Phongamwong, Noelia Barrabes, Waleeporn Donphai, Thongthai Witoon, Guenther Rupprechter, Metta Chareonpanich
Summary: Solar-driven photocatalysis is a promising approach for clean production using sunlight as an energy source. The efficiency of nanocrystalline TiO2 catalysts can be improved by functionalizing them with Au-25 clusters, Au nanoparticles, and chlorophyll. The most effective degradation of rhodamine B was achieved using a P25 catalyst functionalized with both Au-25 and chlorophyll. Various characterization techniques were used to investigate the factors influencing the photocatalytic activity.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Applied
Yvan J. O. Asencios, Nevzat Yigit, Thomas Wicht, Michael Stoeger-Pollach, Alessandra F. Lucredio, Francielle C. F. Marcos, Elisabete M. Assaf, Guenther Rupprechter
Summary: In this study, catalysts of Ni supported on MgO-ZrO2 solid solutions were prepared and characterized. The Ni(30 wt%) supported on MgO-ZrO2 solid solution exhibited high methane conversion and hydrogen selectivity. The catalyst with a 4 mol% MgO content, Ni4MgZr, showed the best catalytic performance.
TOPICS IN CATALYSIS
(2023)
Article
Chemistry, Physical
Philipp Winkler, Maximilian Raab, Johannes Zeininger, Lea M. Rois, Yuri Suchorski, Michael Stoeger-Pollach, Matteo Amati, Rahul Parmar, Luca Gregoratti, Guenther Rupprechter
Summary: The catalytic behavior of Rh particles supported by different materials (Rh, Au, and ZrO2) in H-2 oxidation was investigated using photoemission electron microscopy (PEEM) and scanning photoemission electron microscopy (SPEM). Different catalytic performances were observed depending on the support and Rh particle size, with oscillations ranging from particle size-independent to fully inhibited. The experimental observations were supported by micro-kinetic simulations, which revealed the importance of hydrogen adsorption and oxygen binding in the catalytic process. This study highlights the significance of correlative in situ surface microscopy in understanding the relationship between local structure, composition, and catalytic performance.
Article
Chemistry, Multidisciplinary
Vera Truttmann, Adea Loxha, Rares Banu, Ernst Pittenauer, Sami Malola, Maria Francisca Matus, Yuchen Wang, Elizabeth A. Ploetz, Guenther Rupprechter, Thomas Burgi, Hannu Hakkinen, Christine Aikens, Noelia Barrabes
Summary: Chiral gold nanoclusters were synthesized using the chiral ligand 2-MeBuSH, leading to the unexpected formation of enantiopure chiral clusters. The chiral activity of Au-144 was found to be stronger than Au-38 or Au-25, as confirmed by experimental evaluation using circular dichroism spectroscopy. The prepared chiral clusters exhibited stability against diastereoisomerization up to temperatures of 80°C. These findings demonstrate the selective preparation of enantiopure, intrinsically chiral, and highly stable thiolate-protected Au nanoclusters, supporting the predicted super chirality in the Au-144 cluster.
Article
Engineering, Chemical
Orrakanya Phichairatanaphong, Nevzat Yigit, Guenther Rupprechter, Metta Chareonpanich, Waleeporn Donphai
Summary: Reducing greenhouse gas emissions and utilizing more renewable clean energy through dry reforming reactions are important. The study found that a CeMgZnAl oxide quad-blend-supported Ni catalyst showed outstanding performance and resistance to coking during dry reforming reactions.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Editorial Material
Chemistry, Applied
Guenther Rupprechter, Zdenek Dohnalek, Anthony F. F. Volpe
TOPICS IN CATALYSIS
(2023)
Article
Chemistry, Applied
Parinya Tangpakonsab, Alexander Genest, Jingxia Yang, Ali Meral, Bingjie Zou, Nevzat Yigit, Sabine Schwarz, Guenther Rupprechter
Summary: CuO/CeO2 nanosphere catalysts were synthesized and tested for CO oxidation and preferential oxidation of CO (PROX) in excess H-2. The catalytic performance was independent of the initial oxidation state of the catalyst (CuO vs. Cu-0), suggesting the formation of the same active phase under reaction conditions. Density functional modeling was applied to understand the intermediate steps of CO oxidation and H-2 transformation.
TOPICS IN CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Surached Thongboon, Thanaphat Chukeaw, Chalida Niamnuy, Supacharee Roddecha, Paweena Prapainainar, Metta Chareonpanich, Passakorn Kingwascharapong, Kajornsak Faungnawakij, Guenther Rupprechter, Anusorn Seubsai
Summary: Regenerated cellulose (RC) produced from waste pineapple leaves was used to develop a colorimetric sensor called Cu-PAN sheet (RCS), which changed color when exposed to H2S. Prediction curves with high accuracy for H2S concentrations were developed using a colorimeter method. The developed RCS showed excellent stability and could be used as an intelligent indicator of meat spoilage in food packaging.
Article
Chemistry, Multidisciplinary
Thitiwut Sukprom, Pooripong Somchuea, Sarannuch Sringam, Thongthai Witoon, Metta Chareonpanich, Pawin Iamprasertkun, Kajornsak Faungnawakij, Gunther Rupprechter, Anusorn Seubsai
Summary: This study investigated the direct conversion of methane (CH4) to value-added hydrocarbons (C2+) using a hybrid catalyst. The hybrid catalyst consisted of Ni/Al2O3 as the first catalyst layer to convert CH4 to carbon monoxide and K-Co/Al2O3 as the second catalyst layer to convert carbon monoxide to C2+. The hybrid catalyst exhibited effective performance at a relatively low temperature of 490 degrees C, compared to other catalysts used in methane oxidative coupling reactions. The study explored the effects of different operating conditions and found that the highest C2+ yield of 4.3% was achieved at a reactor temperature of 490 degrees C. The addition of K promoter played a crucial role in enhancing C2+ formation. The proposed mechanism for the reaction using the hybrid catalyst was described, and the stability of the catalyst was observed to be excellent during a 24-hour time-on-stream test.
REACTION CHEMISTRY & ENGINEERING
(2023)
Article
Multidisciplinary Sciences
Maximilian Raab, Johannes Zeininger, Yuri Suchorski, Alexander Genest, Carla Weigl, Guenther Rupprechter
Summary: Promoters play an important role in catalysis, but their function and role in reaction instabilities are often unknown. This study demonstrates the local catalytic effect of La in hydrogen oxidation reaction using Rh nanotip as a mimic of single Rh nanoparticle. The presence of La shifts the reaction states, changes the oscillation pattern, and deactivates one of the pacemaker types. The effect originates from the enhanced oxygen activation on the catalyst.
NATURE COMMUNICATIONS
(2023)
Article
Microscopy
C. Gao, C. Hofer, T. J. Pennycook
Summary: Ptychography provides high dose efficiency images that can reveal light elements next to heavy atoms. However, contrast reversals can occur when the projected potential becomes strong. Recent research has shown that these reversals can be counteracted by adapting the focus. This study explains why the best contrast is often found with the probe focused to the middle of the sample and highlights the importance of convergence angle in thin samples to remove contrast reversals.
Article
Microscopy
J. Lindner, U. Ross, T. Meyer, V. Boureau, M. Seibt, Ch. Jooss
Summary: Phase-shifting electron holography is an excellent method with high phase sensitivity to reveal electron wave phase information. An advanced drift correction scheme is proposed in this study, which exploits the interface of the TEM specimen and the vacuum area in the hologram. This method allows for obtaining reliable phase information.
Article
Microscopy
Ali Jaberi, Nicolas Brodusch, Jun Song, Raynald Gauvin
Summary: This study investigates knock-on damage in lithium-ion batteries (LIBs) by computing threshold displacement energies (TDEs) and performing Monte Carlo simulation. The results indicate that Li is most sensitive to knock-on damage at moderate electron energies, and TDE is the principal parameter for assessing Li sensitivity to knock-on damage across similar structures.
Article
Microscopy
Alexander Schroeder, Christopher Rathje, Leon van Velzen, Maurits Kelder, Sascha Schaefer
Summary: This study utilizes novel event-based electron detector platforms to extend the temporal resolution of electron microscopy. By training a neural network to predict electron arrival time, the researchers were able to improve the timing accuracy and achieve a promising solution for enhancing electron timing precision in various electron microscopy applications.
Article
Microscopy
Avi Auslender, Nivedita Pandey, Amit Kohn, Oswaldo Dieguez
Summary: This article describes a faster implementation based on DFT for computing the mean inner potential of crystals, providing quantum-mechanical calculations beyond the independent-atom approximation. The study also reveals the dependence of the mean inner potential on sample boundary conditions, mass density, and magnetic susceptibility, highlighting its correlation with various material properties.
Article
Microscopy
Zhidong Yang, Dawei Zang, Hongjia Li, Zhao Zhang, Fa Zhang, Renmin Han
Summary: In this work, we propose a self-supervised deep learning model for cryo-ET volumetric image denoising based on noise modeling and sparsity guidance. Experimental results demonstrate that our method can achieve reliable denoising by training on single noisy volume and outperform existing methods.
Article
Microscopy
J. Kuttruff, J. Holder, Y. Meng, P. Baum
Summary: In this study, a robust clustering algorithm is proposed that can find clusters in a continuous stream of raw data in real time. This algorithm converts pixel hits measured by hybrid pixel detectors to real single-electron events. By continuously comparing with previous hits, the algorithm efficiently identifies the merging of new and old events.
Article
Microscopy
D. G. Senturk, C. P. Yu, A. De Backer, S. Van Aert
Summary: This article presents a statistics-based method for accurately counting the number of atoms in nanostructures, especially for images acquired with low electron doses and multiple element structures.
Article
Microscopy
Mauricio J. Prieto, Lucas de Souza Caldas, Liviu C. Tanase, Thomas Schmidt, Oscar Rodriguez de la Fuente
Summary: This study presents a synchrotron-based investigation of the synthesis process of a magnetite/hematite bilayer. Ion bombardment gradually transforms hematite into magnetite, and the growth of magnetite leads to the formation of stable boundaries. These findings are significant for understanding novel oxide heterostructures.
Article
Microscopy
Emre Yoruk, Holger Klein, Stephanie Kodjikian
Summary: Beam sensitive nanomaterials pose challenges for crystallographic structure determination. A dose symmetric electron diffraction tomography (DS-EDT) method is developed to reduce beam damage and obtain complete data sets by merging individual datasets from multiple crystals.
Article
Microscopy
A. Pofelski, Y. Zhu, G. A. Botton
Summary: The precision and sensitivity of the GPA method for strain characterization is a widely discussed topic. This study introduces the concept of phase noise and analyzes the parameter of sampling to improve the precision of GPA. Experimental and theoretical results demonstrate that using a larger pixel spacing in STEM can enhance the precision and sensitivity of the GPA method.
Article
Microscopy
Sangjun Kang, Di Wang, Christian Kuebel, Xiaoke Mu
Summary: Transmission electron microscopy is a valuable tool for assessing strain fields within materials. However, using thin specimens in TEM analysis can affect atomic configuration and deformation structure.
