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Efficient epoxidation of propylene over non-noble nickel-based catalyst promoted by alkali metals

Science China Chemistry 2024年第11期67卷 3697-3705页

作者： Wenqian Li Wanting Li xinxin Cao Longfei Chen Yibo Qin Yanfeng Zhu Yanfei Zhang Gai Miao Lingzhao Kong Jiong Li xinqing Chen State Key laboratory of Low Carbon Catalysis and Carbon Dioxide Utilization CAS Key Laboratory of Low-carbon Conversion Science and Engineering Shanghai Advanced Research Institute Chinese Academy of Sciences University of Chinese Academy of Sciences School of Environmental Science and Engineering Suzhou University of Science and Technology Shanghai Synchrotron Radiation Facility Zhangjiang National Lab Shanghai Advanced Research Institute Chinese Academy of Sciences

The application of non-noble metal catalysts in the catalytic direct gas-phase epoxidation of propylene with H2and O2to produce propylene oxide is valuable and challenging. The introduction of alkali metal promoters is one of the effective methods to improve the catalytic activity of catalysts. Herein, a series of alkali metal（Li, Na, K, Rb, and Cs）-promoted Ni/TS-1 catalysts were prepared to deeply understand the effect of alkali metals on the structure-activity relationship for gas-phase epoxidation of propylene. Among them, the Na-Ni/TS-1 catalyst exhibits the highest catalytic activity(propylene conversion of 7.35% and PO formation rate of 157.9 g h-1kgcat-1) and the best stability（long-term stability exceeding 140 h at 200 °C）. x-ray absorption and photoelectron spectroscopy revealed that the electronic structure of Ni can be tuned by the addition of alkali metal ***3-TPD-MS, CO2-TPD-MS, and C3H6-TPD-MS results indicate that the acidity of the catalyst can also be adjusted by the introduction of alkali metal, whereas the Na-Ni/TS-1 catalyst exhibits the strongest C3H6adsorption capacity. Thus, the suitable acid-base properties, unique electronic properties of Ni species, and the strongest propylene adsorption capacity resulted in improved propylene gas-phase epoxidation activity of Na-Ni/TS-1 catalyst. This study not only provides a new strategy for the practical application of nickel-based catalysts in the gas-phase epoxidation of propylene but also provides insights into the promoting effect of alkali metals.

关键词： propylene epoxidation Ni/TS-1 catalyst alkali metal precipitating agents

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Exploring the role of iron in Fe_(5)Ni_(4)S_(8)toward oxygen evolution through modulation of electronic orbital occupancy

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Journal of Energy Chemistry 2024年第5期92卷 52-62页

作者： Zhengyan Du Zeshuo Meng Haoteng Sun Yifan Li Chao Jiang Yaxin Li xiaoying Hu Yi Cui Shansheng Yu Hongwei Tian Key laboratory of Automobile Materials of MOE School of Materials Science and EngineeringJilin UniversityChangchun 130012JilinChina College of Science and laboratory of Materials Design and Quantum Simulation Changchun UniversityChangchun 130022JilinChina i-lab Vacuum Interconnected Nanotech Workstation(Nano-X)Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123JiangsuChina Department of Chemistry Brown UniversityRI 02912United States

Ni-Fe-based catalysts are considered to be among the most active catalysts for the oxygen evolution reaction(OER)under alkaline conditions,with Fe playing a crucial ***,Fe leaching occurs during the reaction due to thermodynamic instability,which has resulted in conflicting reports within the literature regarding its *** clarify this point,we propose a strategy consisting of modulating the electronic orbital occupancy to suppress the extensive loss of Fe atoms during the OER *** calculations,in-situ x-ray photoelectron spectroscopy,molecular dynamics simulations,and a series of characterization showed that the stable presence of Fe not only accelerates the electron transfer process but also optimizes the reaction barriers of the oxygen evolution intermediates,promoting the phase transition of Fe_(5)Ni_(4)S_(8)to highly active catalytic *** modulated Fe_(5)Ni_(4)S_(8)-based pre-catalysts exhibit improved OER activity and long-term *** study provides a novel perspective for understanding the role of Fe in the OER process.

关键词： Oxygenevolution Fe_(5)Ni_(4)S_(8) Electronic orbital occupancy modulation Reconstruction dynamics

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Regulating interfacial stability of SiO_(x) anode with fluoride-abundant solid–electrolyte interphase by fluorine-functionalized additive

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Rare Metals 2024年第2期43卷 671-681页

作者： Subin Lee Taeeun Yim Advanced Batteries laboratory Department of ChemistryIncheon National UniversityIncheon22012Republic of Korea research Institute of Basic Sciences College of Natural ScienceIncheon National UniversityIncheon22012Republic of Korea

Silicon oxide(SiO_(x))has received remarkable attention as a next-generation battery material;however,the sudden decrease in the cycling retention constitutes a significant challenge in facilitating its ***(2,2,2-trifluoroethyl)phosphite(TTFP),which can control parasitic reactions such as the pulverization of SiO_(x)anode materials and electrolyte decomposition,has been proposed to improve the lifespan of the *** electrochemical reduction of TTFP results in solid-electrolyte interphase(SEI)layers that are mainly composed of LiF,which occur at a higher potential than the working potential of the SiO_(x)anode and carbonate-based *** electrolyte with TTFP exhibited a substantial improvement in cycling retention after 100 cycles,whereas the standard electrolyte showed acutely decreased *** thickness of the SiO_(x)anode with TTFP also changed only slightly without any considerable delamination spots,whereas the SiO_(x)anode without TTFP was prominently deformed by an enormous volume expansion with several internal *** cycled SiO_(x)anode with TTFP exhibited less increase in resistance after cycling than that in the absence of TTFP,in addition to fewer decomposition adducts in corresponding x-ray photoelectron spectroscopy(xPS)analyses between the cycled SiO_(x)*** results demonstrate that TTFP formed SEI layers at the SiO_(x)interface,which substantially reduced the pulverization of the SiO_(x)anode materials;in addition,electrolyte decomposition at the interface decreased,which led to improved cycling retention.

关键词： Lithium-ion batteries(LIBs) Silicon oxide anode Electrolyte Additive Solid-electrolyte interphases(SEI) Tris(2,2,2-trifluoroethyl)phosphite

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Microstructure and mechanical properties stability of pre-hardening treatment in Al-Cu alloys for pre-hardening forming process

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 539-551页

作者： Liping Tang Pengfei Wei Zhili Hu Qiu Pang Hubei Longzhong laboratory Xiangyang 441000China Hubei Key laboratory of Advanced Technology for Automotive Components School of Automotive EngineeringWuhan University of TechnologyWuhan 430070China Hubei Engineering research Center for Green&Precision Material Forming Wuhan University of TechnologyWuhan 430070China Key laboratory of Metallurgical Equipment and Control Technology of Ministry of Education School of Machinery and AutomationWuhan University of Science and TechnologyWuhan 430081China

The stability of the microstructure and mechanical properties of the pre-hardened sheets during the pre-hardening forming(PHF)process directly determines the quality of the formed *** microstructure stability of the pre-hardened sheets was in-vestigated by differential scanning calorimetry(DSC),transmission electron microscopy(TEM),and small angle x-ray scattering(SAxS),while the mechanical properties and formability were analyzed through uniaxial tensile tests and formability *** results in-dicate that the mechanical properties of the pre-hardened alloys exhibited negligible changes after experiencing 1-month natural aging(NA).The deviations of ultimate tensile strength(UTS),yield strength(YS),and sheet formability(Erichsen value)are all less than 2%.Also,after different NA time(from 48 h to 1 month)is applied to alloys before pre-hardening treatment,the pre-hardened alloys possess stable microstructure and mechanical properties as ***,with the extension of NA time before pre-hardening treatment from 48 h to 1 month,the contribution of NA to the pre-hardening treatment is *** a yield strength increment of 20 MPa is achieved,with no loss in *** limited enhancement is mainly attributed to the fact that only a limited number of clusters are transformed into Guinier-Preston(GP)zones at the early stage of pre-hardening treatment,and the formation ofθ''phase inhibits the nucleation and growth of GP zones as the precipitated phase evolves.

关键词： Al-Cu alloy pre-hardened alloy natural aging mechanical properties microstructure

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Insight into the Role and Evidence of Oxygen Vacancies in Porous Single-Crystalline Oxide to Enhance Catalytic Activity and Durability

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research 2024年第2期2023卷 675-683页

作者： Lingting Ye Jiaming Ma Jie Zhang Wen Yin Yuanguang xia Kui xie Key laboratory of Optoelectronic Materials Chemistry and Physics Fujan Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002China Fujian Science&Technology Innovation laboratory for Optoelectronic Information of China FuzhouFujian 350108China Advanced Energy Science and Technology Guangdong laboratory 29 Sanxin North RoadHuizhouGuangdong 116023China Spallation Neutron Source Science Center DongguanGuangdong 523803China

Introducing and stabilizing oxygen vacancies in oxide catalysts is considered to be a promising strategy for improving catalytic activity and ***,we quantitatively create oxygen vacancies in the lattice of porous single-crystallineβ-Ga_(2)O_(3)monoliths by reduction treatments and stabilize them through the long-range ordering of crystal lattice to enhance catalytic activity and *** combination analysis of time-of-flight neutron powder diffraction and extended x-ray absorption fine structure discloses that the preferential generation of oxygen vacancy tends to occur at the site of tetrahedral coordination oxygen ions(O_(Ⅲ)sites),which contributes to the formation of unsaturated Ga-O coordination in the monoclinic *** oxygen vacancies are randomly distributed in lattice even though some of them are present in the form of domain defect in the PSC Ga_(2)O_(3)monoliths after the reduction *** number of oxygen vacancies in the reduced monoliths gives 2.32×10^(13),2.87×10^(13),and 3.45×10^(13)mg^(-1)for the Ga_(2)O_(2.952),Ga_(2)O_(2.895),and Ga_(2)O_(2.880),*** therefore demonstrate the exceptionally high C_(2)H_(4)selectivity of~100%at the C_(2)H_(6)conversion of~37%for nonoxidative dehydrogenation of C_(2)H_(6)to C_(2)H_(4).We further demonstrate the excellent durability even at 620℃for 240 h of continuous operation.

关键词： durability coordination Oxygen

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Robust Giant Octahedral[6+8]Porous Organic Cages for Efficient Ethylene/Ethane Separation

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CCS Chemistry 2024年第9期6卷 2264-2274页

作者： Lijuan Feng Yan-xi Tan El-Sayed MEl-Sayed Fenglei Qiu Wenjing Wang Kongzhao Su Daqiang Yuan State Key laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002 College of Chemistry Fuzhou UniversityFuzhou 350116 Chemical Refining laboratory Refining Department Egyptian Petroleum Research InstituteNasr CityCairo 11727 University of the Chinese Academy of Sciences Beijing 100049 Fujian Science and Technology Innovation laboratory for Optoelectronic Information of China Fuzhou 350108

The exploration of ethane(C_(2)H_(6))-selective porous materials for the direct production of polymer-grade ethylene(C_(2)H_(4))from a C_(2)H_(6)/C_(2)H_(4) mixture in a single energy-saving adsorption step is of utmost importance but remains a significant ***,developing robust C_(2)H_(6)-selective adsorbents with high C_(2)H_(6) capacity and C_(2)H_(6)/C_(2)H_(4) selectivity is urgently needed for industrial *** this study,we have successfully designed and synthesized two novel calix[4]resorcinarene-based porous organic cages(POCs)named CPOC-501 and *** POCs were formed via a Schiff-base reaction involving face-directed[6+8]condensation between a bowlshaped tetratopic tetraformylcalix[4]resorcinarene and triangular tritopic amine *** using single crystal x-ray crystallography revealed that both cages possess large truncated octahedral cavities with a volume of approximately 6500Å3 and 12 accessible rhombic windows with a side length of approximately 10.5Å.Furthermore,the cages exhibited excellent chemical stability under neutral,acidic,and basic conditions and high Brunauer–Emmett–Teller specific surface areas of up to 2175 m^(2) g^(−1) after *** POCs demonstrated superior adsorption capabilities for C_(2)H_(6) over C_(2)H_(4).Notably,CPOC-502 exhibited a C_(2)H_(6) capacity and C_(2)H_(6)/C_(2)H_(4) selectivity of 83 cm^(3) g^(−1) and 2.83,respectively,surpassing most of the best-performing C_(2)H_(6)-selective porous organic materials reported to ***,breakthrough experiments confirmed that both cages efficiently produced polymer-grade C_(2)H_(4)(>99.9%)directly from the C_(2)H_(6)/C_(2)H_(4) mixture,highlighting their outstanding recyclability.

关键词： C_(2)H_(6)/C_(2)H_(4)separation porous organic cages calixresorcinarene gas adsorption and separation host-guest interactions

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Efficient and Fast x-ray Luminescence in Organic Phosphors Through High-Level Triplet-Singlet Reverse Intersystem Crossing

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CCS Chemistry 2024年第2期6卷 334-341页

作者： Yang Zhang Minghong Chen xiaoze Wang Miao Lin Hongyu Wang Weihong Li Fuhai Chen Qing Liao Hongming Chen Qiushui Chen Meijin Lin Huanghao Yang Key laboratory of Molecule Synthesis and Function Discovery College of ChemistryFuzhou UniversityFuzhouFujian 350116 New Cornerstone Science laboratory MOE Key Laboratory for Analytical Science of Food Safety and BiologyCollege of ChemistryFuzhou UniversityFuzhouFujian 350108 College of Materials Science and Engineering Fuzhou UniversityFuzhouFujian 350116

Organic scintillators that efficiently generate bright triplet excitons are of critical importance for highperformance x-ray-excited luminescence in radiation ***,the nature of triplet-singlet spinforbidden transitions in these materials often result in long-lived phosphorescence,which is undesirable for ultrafast x-ray detection and *** we demonstrate that the effect of hybridized local and charge-transfer(HLCT)excited states enables organic scintillators to exhibit highly efficient and fast radioluminescence(RL)in response to x-ray *** experimental and theoretical investigation shows that the oxidized 1,8-naphthalimide-phenothiazine dyad(OMNI-PTZ 2)with HLCT-excited states has an enhanced overlap integral of the highest occupied molecular orbital(HOMO)and lowest unoccupied molecular orbital(LUMO)on MNIπ-orbitals,and moderate donor–acceptor electron *** a result,the RL of these crystals exhibits a 61-fold increase and its monoexponential decay lifetime is three orders of magnitude faster compared to its corresponding thermally activated delayed fluorescence(TADF)molecule MNI-PTZ *** further demonstrate the practical utility of the OMNI-PTZ 2(G)in high-performance x-ray detection and imaging,achieving an x-ray dose sensitivity of 97 nGy s−1 and an exceptional spatial resolution of 20 lp/*** study provides a promising molecular design principle for utilizing triplet excitons to develop high-efficiency and fast x-ray scintillators for the development of next-generation flexible and stretchable x-ray imaging detectors.

关键词： organic scintillators x-ray imaging hybridized local and charge transfer excited state triplet-singlet reverse intersystem crossing high exciton utilization

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Understanding synergistic catalysis on Pt–Cu diatomic sites via operando x-ray absorption spectroscopy in sulfur redox reactions

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eScience 2024年第5期4卷 110-119页

作者： Shuai xie xingjia Chen Leilei Wang Guikai Zhang Haifeng Lv Guolei Cai Ying-Rui Lu Ting-Shan Chan e Jing Zhang Juncai Dong Hongchang Jin xianghua Kong Junling Lu Song Jin xiaojun Wu Hengxing Ji Hefei National laboratory for Physical Sciences at the Microscale CAS Key Laboratory of Materials for Energy ConversionDepartment of Applied ChemistryUniversity of Science and Technology of ChinaHefei 230026China School of Chemistry and Material Sciences CAS Key Laboratory of Materials for Energy Conversionand CAS Center for Excellence in Nanoscience and Synergetic Innovation of Quantum Information and Quantum TechnologyUniversity of Science and Technology of ChinaHefei 230026China Hefei National laboratory for Physical Sciences at the Microscale Department of Chemical PhysicsSchool of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026China Beijing Synchrotron Radiation laboratory Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China National Synchrotron Radiation research Center Hsinchu 300092China School of Chemistry and Chemical Engineering Hefei University of TechnologyHefei 230009China

Sulfur redox reactions render lithium–sulfur(Li–S)batteries with an energy density of>500Whkg−1 but suffer a low practical capacity and fast capacity fade due to sluggish sulfur redox reaction(SRR)kinetics,which lies in the complex reaction process that involves a series of reaction intermediates and proceeds via a cascade ***,we present a Pt–Cu dual-atom catalyst(Pt/Cu-NG)as an electrocatalyst for sulfur redox ***/Cu-NG enabled the rapid conversion of soluble polysulfide intermediates into insoluble Li2S2/Li2S,and consequently,it prevented the accumulation and shuttling of lithium polysulfides,thus outperforming the corresponding single-atom catalysts(SACs)with individual Pt or Cu *** x-ray absorption spectroscopy and density functional theory calculations revealed that a synergistic effect between the paired Pt and Cu atoms modifies the electronic structure of the Pt site through d-orbital interactions,resulting in an optimal moderate interaction of the metal atom with the different sulfide *** optimal interaction enhanced charge transfer kinetics and promoted sulfur redox *** work thus provides important insights on the atomic scale into the synergistic effects operative in dual-atom catalysts and will thus pave the way to electrocatalysts with enhanced efficiency for high-performance Li–S batteries.

关键词： Dual-atom catalysts Sulfur redox reaction Lithium-sulfur batteries Synergistic interaction x-ray absorption spectroscopy

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Spectral Fittings of Warm Coronal Radiation with High Seed Photon Temperature:Apparent Low-temperature and Flat Soft Excess in AGNs

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research in Astronomy and Astrophysics 2024年第7期24卷 135-144页

作者： Ze-Yuan Tang Jun-Jie Feng Jun-Hui Fan School of Mathematics and Information Science Guangzhou UniversityGuangzhou 510006China Center for Astrophysics Guangzhou UniversityGuangzhou 510006China Astronomy Science and Technology research laboratory of Department of Education of Guangdong Province Guangzhou 510006China Key laboratory for Astronomical Observation and Technology of Guangzhou Guangzhou 510006China

A warm corona has been widely proposed to explain the soft excess(SE)in x-ray above the 2-10 ke V power law extrapolation in Active Galactic Nuclei(AGNs).In actual spectral fittings,the warm coronal seed photon temperature(T_s)is usually assumed to be far away from the soft x-ray,but kT_scan reach close to 0.1 ke V in the standard accretion disk *** this study,we used Monte Carlo simulations to obtain radiation spectra from a slab-like warm corona and fitted the spectra using the spherical-geometry-based routine THCOMP or a thermal *** findings reveal tha high T_scan influence the fitting results.A moderately high kT_s(around 0.03 ke V)can result in an apparent low-temperature and flat SE,while an extremely high kT_s(around 0.07 ke V)can even produce an unobserved blackbody-like *** conclusions indicate that,for spectral fittings of the warm coronal radiation(SE in AGNs),kT_sshould be treated as a free parameter with an upper limit,and an accurate coronal geometry is necessary when kT_s>0.01 ke V.

关键词： galaxies active-accretion-accretion disks-black hole physics

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Asymmetrically coordinated main group atomic In-S_(1)N_(3)interface sites for promoting electrochemical CO_(2)reduction

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Nano research 2024年第6期17卷 5011-5021页

作者： Yan Gao Jinlong Ge Jingqiao Zhang Ting Cao Zhiyi Sun Wensheng Yan Yu Wang Jie Lin Wenxing Chen Zheng Liu Anhui Provincial Engineering laboratory of Silicon-based Materials Bengbu UniversityBengbu 233030China State Key laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China SEPA Key laboratory of Eco-Industry Chinese Research Academy of Environmental SciencesBeijing 100012China Ningbo Institute of Materials Technology and Engineering Chinese Academy of ScienceNingbo 315201China Energy&Catalysis Center School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China National Synchrotron Radiation laboratory University of Science and Technology of ChinaHefei 230029China Shanghai Synchrotron Radiation Facilities Shanghai Institute of Applied PhysicsChinese Academy of ScienceShanghai 201204China

Designing catalysts with highly active,selectivity,and stability for electrocatalytic CO_(2)to formate is currently a severe ***,we developed an electronic structure engineering on carbon nano frameworks embedded with nitrogen and sulfur asymmetrically dual-coordinated indium active sites toward the efficient electrocatalytic CO_(2)reduction *** expected,atomically dispersed In-based catalysts with In-S_(1)N_(3)atomic interface with asymmetrically coordinated exhibited high efficiency for CO_(2)reduction reaction(CO_(2)RR)to *** achieved a maximum Faradaic efficiency(FE)of 94.3%towards formate generation at−0.8 V *** hydrogen electrode(RHE),outperforming that of catalysts with In-S2N2 and In-N4 atomic *** at a potential of−1.10 V ***,In-S_(1)N_(3)achieves an impressive Faradaic efficiency of 93.7%in flow *** catalytic performance of In-S_(1)N_(3)sites was confirmed to be enhanced through in-situ x-ray absorption near-edge structure(xANES)measurements under electrochemical *** discovery provides the guidance for performance regulation of main group metal catalysts toward CO_(2)RR at atomic scale.

关键词： indium single-site catalyst main group metal asymmetrical coordination CO_(2)reduction reaction structure-activity relationship

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