检索结果-南通市图书馆

Effect of Y,Al Co‑Doping on Hydrogen Storage Properties of La–Mg–Ni‑Based Alloys

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1399-1410页

作者： Guanjiu Wu Yichao Xie Yuan Li Qing Wang Chenfeng Fan Wenfeng Wang Lu Zhang Shumin Han Hebei key laboratory of Applied chemistry Yanshan UniversityQinhuangdao 066004China state key laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

La–Mg–Ni-based hydrogen storage alloys have excellent hydrogen storage *** work reports the hydrogen storage performance of a series of A_(2)B_(7)-type La_(0.96)Mg_(0.04)N_(i3.34)Al_(0.13)alloy and La_(0.96-x)Y_(x)Mg_(0.04)Ni_(3.47–0.6x)Al_(0.6x)(x=0,0.22,0.33,0.44)alloys,and explores the effect of Y and Al element combined substitution on the microstructure and hydrogen storage performance of A_(2)B_(7)-type La–Mg–Ni-based *** alloys are composed of Ce_(2)Ni_(7)phase and LaNi_(5)*** the increase of x,the cell volume of Ce_(2)Ni_(7)phase decreases,while that of LaNi_(5)phase increases,indicating that Y atom mainly enters Ce_(2)Ni_(7)phase and Al atom mainly enters LaNi_(5)*** appropriate amount of co-substitution increases the hydrogen storage capacity and reduces the hydrogen absorption/desorption plateau pressure hysteresis of the *** x=0.44,the hydrogen storage capacity of the alloy is 1.449 wt%,and the hysteresis coefficient is *** cell volume of Ce_(2)Ni_(7)phase and LaNi_(5)phase expands to different degrees after 20 absorption/desorption *** the increase of x,the volume expansion rate decreases,and the cycle capacity retention rate also gradually *** is related to the amorphization of Ce_(2)Ni_(7)*** x=0.22,the capacity retention rate of the alloy is 91.4%.

关键词： La-Mg-Ni-based alloys Gas-phase hydrogen storage performance Ce_(2)Ni_(7)phase LaNi_(5)phase Capacity retention rate

Effects of length alteration of OPE-containing mono- and dinuclear alkynylplatinum(II) terpyridine complexes on photophysical, structural and morphological properties

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第10期17卷 8893-8903页

作者： Jason Koon-Lam Poon Sammual Yu-Lut Leung Eric Ka-Ho Wong Vivian Wing-Wah Yam Institute of Molecular Functional Materials State Key Laboratory of Synthetic Chemistry and Department of ChemistryThe University of Hong KongHong Kong 999077China

A series of mononuclear complexes and unsymmetric dinuclear alkynylplatinum(II)terpyridine complexes with oligo(paraphenylene ethynylene)(OPE)-derived backbone with a variation of the lengths of alkoxy chains and OPE backbones was *** morphological properties,packing lattice and gelation behaviors of the mononuclear complexes were systematically studied,and the thermodynamic parameters and packing lattices of the dinuclear complexes were also investigated,providing further insights into the roles of the non-covalent interactions and their delicate balance in constructing sophisticated supramolecular *** and nanotube formation have been observed upon a delicate control of the intermolecular interactions by altering the lengths and structural dimensions of the complexes.

关键词： supramolecular chemistry self-assembled nanostructures platinum(II)complexes metallogel

Thermodynamic nature of black holes in coexistence region

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 27-32页

作者： Shao-Wen Wei Yu-Xiao Liu Lanzhou Center for theoretical Physics Key Laboratory of Theoretical Physics of Gansu Provinceand Key Laboratory of Quantum Theory and Applications of Mo ELanzhou UniversityLanzhou 730000China Institute of theoretical Physics&Research Center of Gravitation Lanzhou UniversityLanzhou 730000China

Studying the system state of coexistence regions will peek into to reveal microscopic interactions between different phases of a thermodynamic ***,there is no effective method to study thermodynamic nature of the coexistence black hole regions for the failure of the equation of *** at these coexistence states,in this work,we develop a general approach by introducing two new ratio *** first one is the ratio of the horizon radii of the saturated coexistence small and large black holes,and the second one measures that of the small black hole molecule number to the total molecule *** demonstrate that the first parameter can serve as an order parameter to characterize the first-order phase *** study also shows that the black hole state in the coexistence region is uniquely determined by these two introduced parameters bounded between 0 and *** results are quite significant in the analytical study of phase transition and the microscopic nature of black hole in the coexistence regions.

关键词： transition. state. thermodynamic

Hydrodechlorination of trifluoro-trichloroethane to chlorotrifluoroethylene:Revealing the deactivation mechanism and regeneration strategy of Pd-Cu/AC catalyst

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第6期70卷 261-268页

作者： Song Tian Yicheng Chen Xiaoyu Wen Bingcheng Li Jian Lu Zile Li Feng Feng Qingtao Wang Qunfeng Zhang Xiaonian Li state key laboratory Breeding Base of Green chemistry Synthesis Technology Institute of Industrial Catalysis of Zhejiang University of TechnologyHangzhou 310014China state key laboratory of Fluorine&Nitrogen Chemicals Xi'an Modern Chemistry Research InstituteXi'an 710065China

Chlorotrifluoroethylene(CTFE)is a vital fluorinated olefinic monomer produced through the catalytic hydrodechlorination of trichlorotrifluoroethane(CFC-113),an eco-friendly ***,hydrodechlorination catalysts for olefin production often suffer from poor *** Pd/AC catalyst and Pd-Cu/AC catalyst prepared by co-impregnation method exhibited poor stability,Pd-Cu/AC catalyst with CFC-113 conversion dropping to around 37%after 50 h of hydrodechlorination ***-Emmett-Teller,transmission electron microscopy,X-ray photoelectron spectroscopy,and X-ray diffraction of fresh and deactivated Pd/AC catalysts indicate that the deactivation of Pd/AC catalysts is due to high-temperature agglomeration of *** analysis of fresh and deactivated Pd-Cu/AC catalysts using Brunauer-Emmett-Teller,transmission electron microscopy,and thermogravimetric analysis techniques revealed decreased dispersion of active sites,reduced surface area,catalyst aggregation deactivation,and a significant decrease in Cu ***,the results of NH3-TPD revealed that the acid sites of the catalyst increased significantly.X-ray diffraction spectra indicated the formation of new species,basic copper chloride(Cu_(2)(OH)_(3)Cl),during the *** the reaction progressed,these new species agglomerated,leading to a gradual loss of catalyst ***,the deactivated catalyst was successfully reactivated using a simple alkaline washing method.

关键词： CFC-113 Hydrodechlorination Chlorotrifluoroethylene Catalyst deactivation

Degradation mechanisms and stabilization strategies of ruthenium-based catalysts for OER in the proton exchange membrane water electrolyzer

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2024年第1期34卷 207-222页

作者： Ming Yang Hongxiang Wu Zhaoping Shi Yibo Wang Jiahao Yang Jing Ni Pengbo Wang Yuqing Cheng Ziang Wang Meiling Xiao Changpeng Liu Wei Xing laboratory of Advanced Power Sources Changchun Institute of Applied Chemistry Chinese Academy of Sciences School of Applied chemistry and Engineering University of Science and Technology of China Jilin Province key laboratory of Low Carbon Chemical Power Sources state key laboratory of Electroanalytical chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences

Designing economical oxygen evolution reaction(OER) electrocatalysts with high activity and long-term stability is essential to promote the scale-up applications of proton exchange membrane water electrolyzer(PEMWE) for hydrogen production. Ruthenium(Ru)-based materials with high intrinsic activity are hailed as the most promising catalysts, but still infeasible for practical application considering their long unresolved poor stability(only dozens of lifespan). Thus, tremendous efforts have been devoted to uncovering the degradation mechanisms and developing stabilization strategies for the Ru-based catalysts. In this review, starting from summarizing the fundamental understanding of deactivation mechanisms, a picture of the stability issue of Ru-based catalysts is proposed, which is followed by a detailed discussion on the recently developed strategies and progress made on enhancing durability. Finally, insights on the prospects for the future development of stable and practical Rubased OER catalysts are provided.

关键词： OER Ru-based catalysts PEMWE Degradation mechanisms Stabilization strategies

Transition-metal-catalyzed remote meta-C-H alkylation and alkynylation of aryl sulfonic acids enabled by an indolyl template

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第8期35卷 254-259页

作者： Pengfei Zhang Qingxue Ma Zhiwei Jiang Xiaohua Xu Zhong Jin College of chemistry State Key Laboratory of Elemento-organic ChemistryNankai UniversityTianjin 300071China key laboratory of Xinjiang Native Medicinal and Edible Plant Resource chemistry College of Chemistry and Environmental SciencesKashi UniversityKashgar 844007China

Transition-metal-catalyzed remote sp^(2)C-H functionalization of aryl sulfonic acids was hardly ever real-ized owing to competitive ortho-C-H functionalization of aryl sulfonates and electron-deficient nature of phenyl ***,with the assistance of a practical biaryl indolyl directing template,palladium-catalyzed remote sp^(2)C-H alkylation of aryl sulfonic acids have been achieved in moderate to good yields with exclusive meta ***,remote meta-selective C-H alkynylation of aryl sulfonic acids was also accomplished with a rhodium *** meta-C-H functionalized products proved to be the superior synthetic precursors,which are difficult to access using the conventional strategy.

关键词： C-H functionalization Aryl sulfonic acid Site-selectivity Transition-metal catalysis Alkylation Alkynylation

Cobalt(Ⅲ)hydride HAT mediated enantioselective intramolecular hydroamination access to chiral pyrrolidines

在线全文

学校读者我要写书评

暂无评论

Science China chemistry 2024年第6期67卷 2002-2008页

作者： Qi Meng Tao Qin Huanran Miao Ge Zhang Qian Zhang Jilin Province key laboratory of Organic Functional Molecular Design&Synthesis Department of ChemistryNortheast Normal UniversityChangchun130024China state key laboratory of Organometallic chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai200032China

Enantioenriched pyrrolidines and derivatives are ubiquitous substructures in compounds of importance to medicinal and biological ***,we report an efficient cobalt-catalyzed intramolecular asymmetric hydroamination reaction that produces chiral pyrrolidines with good to excellent yield and *** with previously reported radicalinvolved methodologies for enantioenriched pyrrolidines,these conditions feature two elegant versatilities,enabling(1)the use of cobalt-catalyzed hydrogen atom transfer(HAT)to generate organocobalt intermediates that bring radical reaction to organometallic chemistry,and(2)enantioselective intramolecular C-N bond forging through an S_(N)2-like displacement involving dynamic kinetic resolution(DKR).This approach provides a new alternative and efficient methodology for enantioselective radical-involved C-N bond construction that can be used in the synthesis of both chiral pyrrolidines and homologous nitrogen heterocycles.

关键词： asymmetric catalysis radical hydroamination cobalt catalysis hydrogen atom transfer

Mn incorporated RuO2 nanocrystals as an efficient and stable bifunctional electrocatalyst for oxygen evolution reaction and hydrogen evolution reaction in acid and alkaline

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第10期35卷 220-226页

作者： Jing Cao Dezheng Zhang Bianqing Ren Ping Song Weilin Xu state key laboratory of Electroanalytical chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences University of Science and Technology of China

The development of efficient and stable bifunctional overall water-splitting is a crucial goal for clean and renewable energy,which is a challenging ***,we report an Mn-incorporated RuO2（MnRuO2） catalyst for highly efficient electrocatalytic oxygen evolution reaction （OER） and hydrogen evolution reaction （HER） in acid and alkaline *** from a more electrochemical active area with the incorporation of Mn,the Mn-RuO2required an overpotential of 200 mV to attain a current density of 10 mA/cm2for OER in *** result indicates that the doping of Mn into RuO2can enhance the OER *** acidic overall water-splitting electrolyzer with good stability constructed by bifunctional Mn-RuO2only requires a cell voltage of 1.50 V to afford 10 m A/cm2and can operate stably for 50 h at50 mA/cm2,which is better than the state-of-the-art Ru-based ***,the Mn-Ru O2exhibits excellent HER and OER activity in alkaline media,and it shows superior activity and durability for overall water-splitting,only needing a cell voltage of 1.49 V to attain 10 m A/*** present work provides an efficient approach to designing and constructing efficient Ru-based electrocatalysts for overall water-splitting.

关键词： Acid and alkaline Hydrogen evolution reaction Overall water splitting Oxygen evolution reaction RuO2-based solid solution electrocatalysts

Ni-catalyzed highly regio- and stereo-selective diborylative cyclization of 1,6-enynes with diboron reagent

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China chemistry 2024年第3期67卷 981-989页

作者： Qitao Guan Zhen Shen Yiqiang Tian Genping Huang Chun Zhang Institute of Molecular Plus Tianjin Key Laboratory of Molecular Optoelectronic ScienceDepartment of ChemistrySchool of SciencesTianjin UniversityTianjin 300072China state key laboratory of Elemento-Organic chemistry Nankai UniversityTianjin 300071China

The Ni-catalyzed highly selective diborylative cyclization of 1,6-enynes with diboron reagent has been developed. When pinB-Bdan was used, multiple types of boron-containing functional groups could be installed into organic molecule with great chemoselectivity and regioselectivity though this reaction. Meanwhile, if B_2pai_2 was employed, the asymmetric diborylative cyclization could be well induced by using strategy of dynamic kinetic resolution. Importantly, the above reactions could afford desired product with 100% atomic economy, and could be compatible with different series of substituents. The studies of further transformation well illustrated that different type products could serve diverse synthetic strategy. Notably, the reaction mechanism was intensively studied by density functional theory(DFT) calculations, which could reveal the mechanism of regio- and enantio-selective control.

关键词： nickel-catalyzed organoboron cyclization regioselectivity enantioselectivity