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Chinese Chemical Letters 2024年第7期35卷 470-472页

作者： Shunshun Jiang Ji Zhang Jing Wang Shan-Tao Zhang School of Materials Science and Engineering Nanjing University of Science&TechnologyNanjing 210094China State Key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China National Laboratory of Solid State Microstructures Department of Materials Science and EngineeringCollege of Engineering and Applied Science&Jiangsu Key Laboratory of Artificial Functional Materials&Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

The rapid development of high-power and pulsed-power techniques inspires extensive investigates on high-performance ceramic-based ***,the low recoverable energy density(Wrec)hampers their wider ***,the non-stoichiometric Bi_(0.5)Na_(0.5)TiO_(3)-based ceramics were designed and *** proper introduction of oxygen vacancies facilitated activating defect dipole,giving rise to reduced remanent ***,the optimal composition exhibited an exceptional high Wrec of 8.3 J/cm^(3),a high efficiency of 85%,and excellent anti-fatigue and thermal *** work provides an efficient approach to explore ceramic capacitors with high capacitive energy storage performances.

关键词： non-stoichiometric Bi_(0.5)Na_(0.5)TiO_(3) Ceramic capacitor Energy density Thermal stability

Identifying the general trend of activity of non-stoichiometric metal oxide phases for CO oxidation on Pd(111)

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Science China Chemistry 2019年第6期62卷 784-789页

作者： Ziyun Wang P.Hu School of Chemistry and Chemical Engineering Queen's University Belfast

Oxidation state changes under reaction conditions are very common in heterogeneous catalysis. However, due to the limitation of experiment and computational methods, the relation between oxidation state and catalytic activity is not clear. Herein, we obtain the most stable structures of palladium oxide films with different oxidation states on palladium metal surfaces using density functional theory calculations and a state-of-the-art optimization method, namely the particle swarm optimization. These structures clearly show the process of palladium oxide film formation on metallic surfaces. Using CO oxidation as a model reaction, we find that the activities increase first and then decrease with the increase of oxidation states, peaking at Pd_4O_3. Our findings offer an understanding of the phase transformation and the activity of non-stoichiometric phases.

关键词： DFT non-stoichiometric oxide CO oxidation

Structure of non-stoichiometric Sr_6Gd_(0.61)Sc_(1.39)(BO_3)_6 Crystal

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Chinese Journal of Structural Chemistry 2004年第5期23卷 537-539页

作者： HUZu-Shu LINZhou-Bin CHENJiu-Tong WANGGuo-Fon StateKeyLaboratoryofStructuralChemistry FujianInstituteofResearchontheStructureofMatterTheChineseAcademyofSciencesFuzhouFujian350002China GraduateSchooloftheChineseAcademyofSciences Beijing100039China

The crystal of the title compound Sr6Gd0.61Sc1.39(BO3)6 (Mr = 1037.00) was grown by Czochralski method. It crystallizes in trigonal, space group 3Rwith a = 12.415(2), c = 9.274(2) ? Z = 3, V = 1238.0(4) 3, Dc = 4.173 g/cm3, l(MoKa) = 0.71073 ? m = 22.278 mm-1, F(000) = 1411, S = 1.213, the final R = 0.0577 and wR = 0.1414 for 401 observed reflections with I>2s(I). In the structure Gd(1)O6 (Gd(1) = Gd0.46 + Sc0.54) and Gd(2)O6 (Gd(2)= Gd0.15 + Sc0.85) are alternately stacked between the planar triangular BO3 groups to form chains extending along the trigonal axis. These chains are connected through the 9-coordinate Sr atoms.

关键词： crystal structure Sr6Gd0.61Sc1.39(BO3)6 crystal non-stoichiometric

Lattice vibrational characteristics,crystal structures and dielectric properties of non-stoichiometric Nd_((1+x))(Mg_(1/2)Sn_(1/2))O_(3) ceramics

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Journal of Materiomics 2020年第3期6卷 476-484页

作者： Zhikai Cao En-Cai Xiao Xue-Hui Li Zhenxing Yue Guohua Chen Ying Chen Kaixin Song Huanfu Zhou Ze-Ming Qi Feng Shi School of Material Science&Engineering Shandong University of Science and TechnologyQingdao266590China College of Arts and Design Shandong Jiaotong UniversityJinan250357China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing100084China Guangxi Key Laboratory of Information Materials Guilin University of Electronic TechnologyGuilin541004China Key Laboratory of Inorganic Functional Materials and Devices Shanghai Institute of CeramicsChinese Academy of Sciences1295 Dingxi RoadShanghai200050China School of Electronics Information Hangzhou Dianzi UniversityHangzhou310018China Guangxi Ministry-Province Jointly-Constructed Cultivation Base for State Key Laboratory of Processing for non-ferrous Metal and Featured Materials School of Materials Science and EngineeringGuilin University of TechnologyGuilin541004China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei230029China Key Laboratory of Processing and Testing Technology of Glass&Functional Ceramics of Shandong Province School of Materials Science and EngineeringQilu University of Technology(Shandong Academy of Sciences)Jinan250353China

non-stoichiometric Nd_((1+x))(Mg_(1/2)Sn_(1/2))O_(3)(-0.04=x≤0.04,NMS)ceramics were fabricated via a conventional solid-state reaction *** structures and morphologies were investigated by Xray diffraction(XRD)and scanning electron microscopy(SEM),*** main crystalline phase is monoclinic Nd(Mg_(1/2)Sn_(1/2))O_(3) with a double perovskite structure(P21/n space group)for the NMS system proved by *** sample at x=0.01 has the best crystallinity and evenly distributed crystal grains observed by *** optimum performances(ε_(r)=19.87,Q×f=41840 GHz,f=12.05 GHz)are obtained at x=*** vibrational modes of the Raman spectra were assigned and illustrated,in *** dielectric properties obtained by fitting infrared reflectance spectra with the help of four-parameter semi-quantum model are consistent with the calculated values by microscopic polarization and damping *** reverse translational vibration of the NdeMgO_(6),the F_(5u)^((5)) mode,provides the greatest contribution to the dielectric *** relationships between crystal structures and dielectric properties were mainly established using lattice vibrational modes as a media.

关键词： Microwave dielectric ceramics non-stoichiometric Lattice vibrational characteristics Crystal structures Dielectric properties

Thermochemical splitting of CO_(2) on perovskites for CO production: A review

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Journal of Energy Chemistry 2024年第3期90卷 464-485,I0011页

作者： Biduan Chen Harriet Kildahl Hui Yang Yulong Ding Lige Tong Li Wang School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China School of Chemical Engineering University of BirminghamBirmingham B152TTUnited Kingdom Beijing Engineering Research Centre of Energy Saving and Environmental Protection Beijing 100083China

Energy supply dominated by fossil energy has been and remains the main cause of carbon dioxide emissions,the major greenhouse gas leading to the current grave climate change *** technical pathways have been proposed to address the *** capture and utilization(CCU) represents one of the approaches and thermochemical CO_(2) splitting driven by thermal energy is a subset of the CCU,which converts the captured CO_(2) into CO and makes it possible to achieve closed-loop carbon ***-active catalysts are among the most critical components of the thermochemical splitting cycles and perovskites are regarded as the most promising *** we review the latest advancements in thermochemical cycles based on perovskites,covering thermodynamic principles,material modifications,reaction kinetics,oxygen pressure control,circular strategies,and demonstrations to provide a comprehensive overview of the topical *** cycles based on such materials require the consideration of trade-off between cost and efficiency,which is related to actual material used,operation mode,oxygen removal,and heat *** of efforts have been made towards improving reaction rates,conversion efficiency and cycling stability,materials related research has been lacking-a key aspect affecting the performance across all above *** perovskites and composite perovskites arise recently as a potentially promising addition to material *** such materials,more effective oxygen removal would be needed to enhance the overall efficiency,for which thermochemical or electrochemical oxygen pumps could contribute to efficient oxygen removal as well as serve as means for inert gas *** integration of thermochemical CO_(2) splitting process with downstream fuel production and other processes could reduce costs and increase efficiency of the *** represents one of the directions for the future research.

关键词： Perovskite Thermochemical cycles CO_(2) splitting Fuel production non-stoichiometric

On the Galvanic Modification of Seawater

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World Journal of Condensed Matter Physics 2019年第4期9卷 112-121页

作者： Alexander Shimkevich NRC Kurchatov Institute Moscow Russia

Chemical properties of seawater are studied at forced shifting of Fermi level εF? in the band gap of liquid water due to deviation of its composition H2O1−z ( |?z|−13 ) from the stoichiometric one ( z = 0 ). It is shown that the hypo-stoichiometric state ( z > 0 ) of seawater emerges when Fermi level is shifted to the local electron level ?εH3O of hydroxonium H3O+ in galvanic cell with the strongly polarized anode and the quasi-equilibrium cathode. Then, each εH3O is occupied by electron and hydroxonium radicals [H3O]? together with hydroxide anions [OH−]?form in seawater hydrated electrons [(H2O)2−] . The opposite hyper-stoichiometric state ( z εOH for removing electron from each hydroxide ion OH−and forming hydroxyl radicals [OH] as strong oxidizers. It turned out that the ions of sodium and chlorine are connected into hydrates of sodium hypochlorite NaClO in this case.

关键词： non-stoichiometric Seawater Band Gap Fermi Level Galvanic Cell Electron Donor Sodium Hypochlorite