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1دورية أكاديمية
المؤلفون: Jiajia Lu, Peng‐Jun Deng, Gaoliang Fu, Xiangyu Meng, Shouren Zhang, Baocheng Yang
المصدر: ChemElectroChem, Vol 11, Iss 10, Pp n/a-n/a (2024)
مصطلحات موضوعية: Electrocatalyst, oxygen reduction reaction, metal-nitrogen-carbon, atomic-level dispersion, dynamic evolution, Industrial electrochemistry, TP250-261, Chemistry, QD1-999
الوصف: Abstract The quest for alternatives to Pt as an oxygen reduction electrocatalyst, possessing high activity, stability, and abundant reserves, holds great significance for H2/O2 fuel cells. Recently, metal‐nitrogen‐carbon (M‐N‐C) electrocatalysts have garnered substantial attention as promising substitutes. These electrocatalysts not only exhibit well‐defined structures but also offer the flexibility to adjust the central metal atoms and coordination atoms. It is beneficial in elucidating the active sites during the catalytic process and in the design of highly active electrocatalysts. In this review, the real active site of M‐N‐C electrocatalyst‐driven ORR is investigated in depth by in situ characterization techniques such as X‐ray absorption spectroscopy, Raman spectroscopy, Fourier‐transform infrared spectroscopy. It′s worth noting that the catalytic activity of M‐N‐C electrocatalysts originates from the dynamic evolution of electrocatalyst structure. Subsequently, we review various synthetic strategies, including the wet chemistry method, spatial confinement, and template‐assisted method, aimed at the rational design of M‐N‐C electrocatalysts. Moreover, recent progresses of M‐N‐C electrocatalysts with varying configurations, encompassing single‐atom, and double‐atom electrocatalysts are discussed, Finally, summary and perspectives on the development of M‐N‐C are provided.
وصف الملف: electronic resource
العلاقة: https://doaj.org/toc/2196-0216Test
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2دورية أكاديمية
المؤلفون: Francesca Nonne, Lucia Dello Iacono, Sara Bertuzzi, Luca Unione, Daniela Proietti, Nathalie Norais, Immaculada Margarit, Roberto Adamo, Jesús Jiménez-Barbero, Filippo Carboni, Maria Rosaria Romano
مصطلحات موضوعية: Biophysics, Biochemistry, Medicine, Biotechnology, Immunology, Chemical Sciences not elsewhere classified, Information Systems not elsewhere classified, structural requirements necessary, multidisciplinary structural approach, minimal structural epitope, haemophilus influenzae <, cps immunological determinants, cps recognized, cps recognition, type b, third one, study demonstrates, ray crystallography, powerful tool, nmr ), nanomagnetic resonance, generally composed, gaining information, far licensed, enzymatic approaches, directly engaged, detailed information, carrier proteins, atomic level, alternative technologies
الوصف: Glycoconjugate vaccines so far licensed are generally composed of a native or size-reduced capsular polysaccharide conjugated to carrier proteins. Detailed information on the structural requirements necessary for CPS recognition is becoming the key to accelerating the development of next-generation improved glycoconjugate vaccines. Structural glycobiology studies using oligosaccharides (OS) complexed with functional monoclonal antibodies represent a powerful tool for gaining information on CPS immunological determinants at the atomic level. Herein, the minimal structural epitope of Haemophilus influenzae type b (Hib) CPS recognized by a functional human monoclonal antibody (hmAb) is reported. Short and well-defined Hib oligosaccharides originating from the depolymerization of the native CPS have been used to elucidate saccharide–mAb interactions by using a multidisciplinary approach combining surface plasmon resonance (SPR), saturation transfer difference-nanomagnetic resonance (STD-NMR), and X-ray crystallography. Our study demonstrates that the minimal structural epitope of Hib is comprised within two repeating units (RUs) where ribose and ribitol are directly engaged in the hmAb interaction, and the binding pocket fully accommodates two RUs without any additional involvement of a third one. Understanding saccharide antigen structural characteristics can provide the basis for the design of innovative glycoconjugate vaccines based on alternative technologies, such as synthetic or enzymatic approaches.
الإتاحة: https://doi.org/10.1021/acscentsci.3c01515.s001Test
https://figshare.com/articles/journal_contribution/A_Multidisciplinary_Structural_Approach_to_the_Identification_of_the_i_Haemophilus_influenzae_i_Type_b_Capsular_Polysaccharide_Protective_Epitope/25269988Test -
3دورية أكاديمية
المؤلفون: Fuping Pan, Lingzhe Fang, Boyang Li, Xiaoxuan Yang, Thomas O’Carroll, Haoyang Li, Tao Li, Guofeng Wang, Kai-Jie Chen, Gang Wu
مصطلحات موضوعية: Biochemistry, Environmental Sciences not elsewhere classified, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, Information Systems not elsewhere classified, unprecedented faradaic efficiency, range mesochannels offer, hydrogen evolution reaction, extensively used fuel, create favorable microenvironments, level current density, high energy barrier, catalyst design principles, carbon support ’, supported cu catalysts, sites possess moderate, bicontinuous mesochannels cu, active sites embedded, 4 , 3 , steer complex co, favor deep co, co adsorption affinity, engineering pore architectures, 2 , situ constructed n, design carbon, block <, low barrier, atomic level
الوصف: Cu-based catalysts hold promise for electrifying CO 2 to produce methane, an extensively used fuel. However, the activity and selectivity remain insufficient due to the lack of catalyst design principles to steer complex CO 2 reduction pathways. Herein, we develop a concept to design carbon-supported Cu catalysts by regulating Cu active sites’ atomic-scale structures and engineering the carbon support’s mesoscale architecture. This aims to provide a favorable local reaction microenvironment for a selective CO 2 reduction pathway to methane. In situ X-ray absorption and Raman spectroscopy analyses reveal the dynamic reconstruction of nitrogen and hydroxyl-immobilized Cu 3 (N,OH-Cu 3 ) clusters derived from atomically dispersed Cu–N 3 sites under realistic CO 2 reduction conditions. The N,OH-Cu 3 sites possess moderate *CO adsorption affinity and a low barrier for *CO hydrogenation, enabling intrinsically selective CO 2 -to-CH 4 reduction compared to the C–C coupling with a high energy barrier. Importantly, a block copolymer-derived carbon fiber support with interconnected mesopores is constructed. The unique long-range mesochannels offer an H 2 O-deficient microenvironment and prolong the transport path for the CO intermediate, which could suppress the hydrogen evolution reaction and favor deep CO 2 reduction toward methane formation. Thus, the newly developed catalyst consisting of in situ constructed N,OH-Cu 3 active sites embedded into bicontinuous carbon mesochannels achieved an unprecedented Faradaic efficiency of 74.2% for the CO 2 reduction to methane at an industry-level current density of 300 mA cm –2 . This work explores effective concepts for steering desirable reaction pathways in complex interfacial catalytic systems via modulating active site structures at the atomic level and engineering pore architectures of supports on the mesoscale to create favorable microenvironments.
الإتاحة: https://doi.org/10.1021/jacs.3c10524.s001Test
https://figshare.com/articles/journal_contribution/N_and_OH-Immobilized_Cu_sub_3_sub_Clusters_In_Situ_Reconstructed_from_Single-Metal_Sites_for_Efficient_CO_sub_2_sub_Electromethanation_in_Bicontinuous_Mesochannels/24939572Test -
4دورية أكاديمية
المؤلفون: Huan Ren, Yuanwei Sun, Frank Hoffmann, Matthias Vandichel, Temilade E. Adegoke, Ning Liu, Conor McCarthy, Peng Gao, Kevin M. Ryan
مصطلحات موضوعية: Biophysics, Biochemistry, Medicine, Computational Biology, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, Information Systems not elsewhere classified, tetrapods semiconductor nanocrystals, battery applications etc, δ , γ , β , α , atomic structure understanding, previous understanding, atomic level, atomic arrangements, turn hinders, theoretical periodicity, theoretical calculations, successfully deciphered, structural complexity, results show, multiple crystals, multielemental semiconductors, mechanistic studies, high elemental, functional properties, elemental orderings, different orientations
الوصف: Semiconductor nanocrystals (NCs) with high elemental and structural complexity can be engineered to tailor for electronic, photovoltaic, thermoelectric, and battery applications etc. However, this greater complexity causes ambiguity in the atomic structure understanding. This in turn hinders the mechanistic studies of nucleation and growth, the theoretical calculations of functional properties, and the capability to extend functional design across complementary semiconductor nanocrystals. Herein, we successfully deciphered the atomic arrangements of 4 different nanocrystal domains in Cu α Zn β Sn γ Se δ (CZTSe) nanocrystals using crucial zone axis analysis on multiple crystals in different orientations. The results show that the essence of crystallographic progression from binary to multielemental semiconductors is actually the change of theoretical periodicity. This transition is caused by decreased symmetry in the crystal instead of previously assumed crystal deformation. We further reveal that these highly complex crystalline entities have highly ordered element arrangements as opposed to the previous understanding that their elemental orderings are random.
الإتاحة: https://doi.org/10.1021/acs.nanolett.3c02810.s001Test
https://figshare.com/articles/journal_contribution/Resolving_Multielement_Semiconductor_Nanocrystals_at_the_Atomic_Level_Complete_Deciphering_of_Domains_and_Order_in_Complex_Cu_sub_sub_Zn_sub_sub_Sn_sub_sub_Se_sub_sub_CZTSe_Tetrapods/25203039Test -
5دورية أكاديمية
المؤلفون: Vobulapuram, Ramesh Kumar, Shaik, Javid Basha, P., Venkatramana, Mekala, Durga Prasad, Lingayath, Ujwala
المصدر: Circuit World, 2021, Vol. 49, Issue 2, pp. 174-179.
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6دورية أكاديمية
المؤلفون: Hongxin Ding, Jinwen Zhang, Wenhua Feng, Qingying Yao, Li Zhang, Yuanhang Ren, Lin Ye, Bin Yue, Heyong He
المصدر: Nanomaterials, Vol 13, Iss 23, p 3053 (2023)
مصطلحات موضوعية: nanoconfined CuZn catalyst, atomic level regulation, MAS NMR, CO2 utilization, methanol, Chemistry, QD1-999
الوصف: CuZn-based catalysts are widely used in CO2 hydrogenation, which may effectively convert CO2 to methanol and alleviate CO2 emission issues. The precise design of a model catalyst with a clear atomic structure is crucial in studying the relationship between structure and catalytic activity. In this work, a one-pot strategy was used to synthesize CuZn@ZSM-5 catalysts with approximately two Cu atoms and one Zn atom per unit cell. Atomic Cu and Zn species are confirmed to be located in the [54.6.102] and [62.104] tilings, respectively, by using magic-angle spinning nuclear magnetic resonance spectroscopy (MAS NMR), synchrotron X-ray powder diffraction (SXRD) and high-signal-to-noise-ratio annular dark field scanning transmission electron microscopy (High SNR ADF-STEM). Catalytic hydrogenation of CO2 to methanol was used as a model reaction to investigate the activity of the catalyst with confined active species. Compared to the Cu@ZSM-5, Zn@ZSM-5 and their mixture, the CuZn@ZSM-5 catalyst with a close Cu–Zn distance of 4.5 Å achieves a comparable methanol space–time yield (STY) of 92.0 mgmethanol·gcatal−1·h−1 at 533 K and 4 MPa with high stability. This method is able to confine one to three metal atoms in the zeolite channel and avoid migration and agglomeration of the atoms during the reaction, which maintains the stability of the catalyst and provides an efficient way for adjustment of the type and number of metal atoms along with the distances between them in zeolites.
وصف الملف: electronic resource
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7دورية أكاديمية
المؤلفون: Min Zheng, Zhihao Yan, Xingbang Hu, Zhuoheng Tu, Youting Wu
مصطلحات موضوعية: Biophysics, Biochemistry, Biotechnology, Ecology, Sociology, Developmental Biology, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, reused 10 times, quantum chemistry calculation, highly efficient uptake, ftir spectroscopic characterizations, atomic level perspective, highly efficient capture, develop novel absorbents, several novel tetrazole, exhibits higher nh, eg ), 3 , n <, mor ), capture nh, absorbents reported, superior selectivity, solubility data, present work, mole ratio, long concern, industrial processes
الوقت: 2
الوصف: It has been of long concern that the separation and recovery of NH 3 from industrial processes, in addition to attracting huge economic interest, also reduce environmental pollution. So, it is very urgent to develop novel absorbents for highly efficient capture of NH 3 . In this study, several novel tetrazole (TetrZ)-based binary deep eutectic solvents (DESs) were formed by mixing TetrZ with 1,2,3-triazole (1,2,3-Tri), ethylene glycol (EG), 2-morpholinoethanol (2-Mor), or N -methyldiethanolemine (MDEA) to absorb NH 3 . TetrZ + 1,2,3-Tri (1:4, mole ratio) not only exhibits higher NH 3 absorption ability of 0.239 g NH 3 ·g DES –1 than that of most absorbents reported to date at 313.15 K and 101.3 kPa, but also shows elevated selectivities of 592.7 for NH 3 /CO 2 , 654.5 for NH 3 /N 2 , and 1033.7 for NH 3 /O 2 . Meanwhile, TetrZ + 1,2,3-Tri (1:4) can be reused 10 times with good absorption capacity retained. Additionally, the solubility data of NH 3 were correlated by the reaction equilibrium thermodynamic model. The NMR and FTIR spectroscopic characterizations were also used to study the absorption mechanism, and quantum chemistry calculation was utilized to further investigate the interactions between NH 3 and DESs from an atomic level perspective. The DESs developed in the present work have the potential to capture NH 3 sustainably, owing to their high solubility, superior selectivity, and desirable reversibility.
الإتاحة: https://doi.org/10.1021/acs.iecr.3c03104.s001Test
https://figshare.com/articles/journal_contribution/Tetrazole-Based_Deep_Eutectic_Solvents_with_Multiple_Hydrogen_Bonding_Sites_for_Highly_Efficient_Uptake_of_NH_sub_3_sub_/24565898Test -
8دورية أكاديمية
المؤلفون: Syed Ul Hasnain Bakhtiar, Pu Ai, Wen Dong, Qi Ma, Junlei Zhao, Guanqun Shi, Fengjun Yan, Ling Miao, Guangzu Zhang, Shenglin Jiang, Wei Luo, Mengyuan Hua, Qiuyun Fu
مصطلحات موضوعية: Medicine, Evolutionary Biology, Science Policy, Biological Sciences not elsewhere classified, Physical Sciences not elsewhere classified, density functional theory, based investigations show, doped tetragonal mo, diluted magnetic semiconductors, co – co, defect clustering effect, 2 , clustering effect, show antiferromagnetic, magnetic order, “ defect, room temperature, opposite trend, one octahedra, mainly decided, magnetization instead, fabrication method, dopant type, diluted fm, defect chemistry, decisive role, becoming viable, atomic level, >< sub
الوصف: Above room temperature T c , magnetism is becoming viable in diluted magnetic semiconductors, which show different magnetic orders, depending on the dopant type and their fabrication method. However, how the defects can influence the magnetic properties remains unclear at the atomic level. In this article, by taking the Co-doped tetragonal MO 2 (t-MO 2 , M = Ti, Sn, Hf, and Zr) as an example, the density functional theory-based investigations show that the magnetic order is mainly decided by the defect clustering effect, following a “defect-distance-based” defect correlation principle. It is found that the distance between two defects (Co–Co) leads to an alteration of magnetic order, where SnO 2 and ZrO 2 show antiferromagnetic (AFM) behavior when the nearest Co–Co distance lies within one octahedron, while a larger distance gives rise to the ferromagnetic (FM) state. In contrast, TiO 2 exhibits an AFM state at the neighboring Co–Co configuration with the nearest Co–Co distance larger than one octahedra, while HfO 2 showed an opposite trend as that of TiO 2 . Furthermore, the position of oxygen vacancies mainly affects the magnitude of magnetization instead of magnetic order. We believe this work would significantly advances the understanding of defect chemistry and condensed matter physics related to diluted FM-AFM systems.
الإتاحة: https://doi.org/10.1021/acs.jpcc.3c06278.s001Test
https://figshare.com/articles/journal_contribution/Decisive_Role_of_the_Defect-Clustering_Effect_in_the_Variation_of_Magnetic_Order_in_Diluted_Magnetic_Binary_Metal_Oxides/24582546Test -
9دورية أكاديمية
المؤلفون: Felipe Lipsky, Luis Henrique da Silveira Lacerda, Lourdes Gracia, Beatriz G. Foschiani, Marcelo Assis, Mónica Oliva, Elson Longo, Juan Andrés, Miguel A. San-Miguel
مصطلحات موضوعية: Biochemistry, Cell Biology, Physiology, Developmental Biology, Infectious Diseases, Environmental Sciences not elsewhere classified, Biological Sciences not elsewhere classified, Information Systems not elsewhere classified, reactive oxygen species, energetically favorable pathway, hydroxyl (• oh, enhanced degradation process, 4 , 3 , 2 , superoxide (•, catalytic process, new perspective, multifunctional competence, molecules regulate, initial stages, experimental results, efficiently activates, bactericidal activity, atomic level
الوصف: Herein, we report a study of Ag 3 PO 4 microcrystals in the accomplishment of their enhanced degradation process and bactericidal activity. Based on experimental results and density functional theory free energy profiles, we propose a new mechanism for the multifunctional competence of the Ag 3 PO 4 (110) surface. Coadsorbed H 2 O and O 2 molecules regulate an energetically favorable pathway that efficiently activates the dissociation of H 2 O and stabilizes the formed reactive oxygen species (ROS) precursors: hydroxyl (•OH) and superoxide (•O 2 – ) radicals. This work is a proof of concept to interpret the surface reactions on Ag 3 PO 4 and provides a new perspective to understand at the atomic level the catalytic process/mechanism for the initial stages of ROS production on metal oxide semiconductor surfaces.
الإتاحة: https://doi.org/10.1021/acs.jpcc.3c06321.s001Test
https://figshare.com/articles/journal_contribution/A_Tale_of_Reactive_Oxygen_Species_on_the_Ag_sub_3_sub_PO_sub_4_sub_110_Surface/24596413Test -
10دورية أكاديمية
المؤلفون: Fan Xue, Qiang Li, Mingxin Lv, Yuanfei Song, Tianxing Yang, Xiaoge Wang, Tianyi Li, Yang Ren, Koji Ohara, Yufei He, Dianqing Li, Qiheng Li, Xin Chen, Kun Lin, Xianran Xing
مصطلحات موضوعية: Biophysics, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, Physical Sciences not elsewhere classified, Information Systems not elsewhere classified, reverse monte carlo, range ordered lattice, optimize chemical activity, heterogeneous catalysis process, unique compressed strain, ethylene adsorption energy, sph , complete acetylene conversion, atomic surface distribution, atomic 3d insight, surface strain, atomic level, performance catalysts, obvious weakening, new path, nanocatalyst surfaces, much higher, main factor, local structure, inherent insufficiency, ethylene selectivity, entailing shape, developing high, big challenge, better understanding
الوصف: Deciphering the three-dimensional (3D) insight into nanocatalyst surfaces at the atomic level is crucial to understanding catalytic reaction mechanisms and developing high-performance catalysts. Nevertheless, better understanding the inherent insufficiency of a long-range ordered lattice in nanocatalysts is a big challenge. In this work, we report the local structure of Pd nanocatalysts, which is beneficial for demonstrating the shape–structure–adsorption relationship in acetylene hydrogenation. The 5.27 nm spherical Pd catalyst (Pd sph ) shows an ethylene selectivity of 88% at complete acetylene conversion, which is much higher than those of the Pd octahedron and Pd cube and superior to other reported monometallic Pd nanocatalysts so far. By virtue of the local structure revelation combined with the atomic pair distribution function (PDF) and reverse Monte Carlo (RMC) simulation, the atomic surface distribution of the unique compressed strain of Pd–Pd pairs in Pd sph was revealed. Density functional theory calculations verified the obvious weakening of the ethylene adsorption energy on account of the surface strain of Pd sph . It is the main factor to avoid the over-hydrogenation of acetylene. The present work, entailing shape-induced surface strain manipulation and atomic 3D insight, opens a new path to understand and optimize chemical activity and selectivity in the heterogeneous catalysis process.
الإتاحة: https://doi.org/10.1021/jacs.3c08619.s001Test
https://figshare.com/articles/journal_contribution/Atomic_Three-Dimensional_Investigations_of_Pd_Nanocatalysts_for_Acetylene_Semi-hydrogenation/24649737Test
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