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Evolution of Zn(Ⅱ) single atom catalyst sites during the pyrolysis-induced transformation of ZIF-8 to n-doped carbons

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Science Bulletin 2020年第20期65卷 1743-1751,M0004页

作者： Qing Wang Toshiaki Ina Wan-Ting Chen Lu Shang Fanfei Sun Shanghai Wei Dongxiao Sun-Waterhouse Shane G.telfer Tierui Zhang Geoffrey I.n.Waterhouse School of Chemical Sciences The University of Auckland.Auckland 1142New Zealand research&Utilization Division Japan Synchrotron Radiation Research InstituteKouto 679-5148Japan Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of Sciences.Beijing 100190China Shanghai Synchrotron.r.diation Facility Shanghai Institute of Applied Physics.Chinese Academy of SciencesShanghai 201204China Department of Chemical and Materials Engineering Faculty of EngineeringThe University of AucklandAuckland 1142New Zealand MacDiarmid Institute for Advanced Materials and nanotechnology Massey UniversityPalmerston North 4442New Zealand

The pyrolysis of zeolitic imidazolate frameworks(ZIFs) is becoming a popular approach for the synthesis of catalysts comprising porphyrin-like metal single atom catalysts(SACs) on n-doped carbons(M-n-C).Understanding the structural evolution of M-n-C as a function of ZIF pyrolysis temperature is important for realizing high performance ***,we report a detailed investigation of the evolution of Zn single atom catalyst sites during the pyrolysis of ZIF-8 at temperatures ranging from 500 to 900℃.results from Zn L-edge and Zn K-edge X-ray absorption spectroscopy studies reveal that tetrahedral Znn4 centers in ZIF-8 transform to porphyrin-like Znn4 centers supported on n-doped carbon at temperatures as low as 600℃.As the pyrolysis temperature in.r.ased in the range 600-900℃,the Zn atoms moved closer to the n4 coordination *** subtle geometry change in the Znn4 sites alters the electron density on the Zn atoms(formally Zn2+),strongly impacting the catalytic performance for the peroxidase-like decomposition of H2 *** catalyst obtained at 800℃(Zn-n-C-800) offered the best performance for H2 O2 *** work provides valuable new insights about the evolution of porphyrin-like single metal sites on n-doped carbons from ZIF precursors and the factors influencing SAC activity.

关键词： Metal single atom catalysts Porphyrin-like sites n-doped carbon Metal organic frameworks X-ray absorption spectroscopy

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Caroline石灰石热分解实验研究

燃烧科学与技术 2001年第2期7卷 110-114页

作者：仲兆平 Marnie telfer 章名耀李大骥徐跃年金保升兰计香张东柯东南大学洁净煤发电与燃烧技术教育部重点实验室热能工程研究所 USEPAOrD/nrMrLAirPollution.r.ventionandCon.r.l NC27711U.S.A SchoolofChemicalEngineeringCurtainUniversityofTechnology WA6845Australia

用热重分析仪进行了 Caroline石灰石的热分解实验。石灰石的粒径分布在 5 3μm至 1.0 mm之间 ,二氧化碳的分压和总压在一定范围内 ,温度在 70 0～ 90 0℃之间。结果表明 ,Caroline石灰石的颗粒尺寸对热分解速度没有影响。各种二氧化碳... 详细信息

用热重分析仪进行了 Caroline石灰石的热分解实验。石灰石的粒径分布在 5 3μm至 1.0 mm之间 ,二氧化碳的分压和总压在一定范围内 ,温度在 70 0～ 90 0℃之间。结果表明 ,Caroline石灰石的颗粒尺寸对热分解速度没有影响。各种二氧化碳分压下的 Caroline石灰石热分解实验发现 ,粒径为 0 .2 1～ 0 .35 mm和 0 .5～ 0 .6 mm时 ,热分解速度正比于平衡状态下的二氧化碳分压减去反应界面处的二氧化碳分压 ,即 p CO2e- p CO2i。粒径在 0 .85～ 1.0 mm和 0 .5～ 0 .6 mm之间的大颗粒 ,在较高压力 (最高压力为 0 .5 MPa)的氮气环境内 ,二氧化碳分压影响热分解速度与其常量摩尔分数 y1 有关 ,在此条件下 ,热分解速度正比于 (p CO2e- p CO2i- p· y1 )。粒径为 0 .2～ 0 .35 mm的颗粒 ,计算转化率达到 10 0 %时热分解速率 ,必须考虑 y1 ,其值从 85 0℃的 0 .0 3增加到 90 0℃的 0 .2

关键词：石灰石热分解反应动力学实验煤气化炉

Large-scale synthesis of n-doped carbon capsules supporting atomically dispersed iron for efficient oxygen.r.duction.r.action electrocatalysis

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eScience 2022年第2期2卷 227-234页

作者： Hui Yang Yanfang Liu Xiaolu Liu Xiangke Wang He Tian Geoffrey I.n.Waterhouse Paul E.Krugere Shane Gtelfer Shengqian Ma Department of Chemistry University of North TexasDentonTX76201United States College of Environmental Science and Engineering North China Electric Power UniversityBeijing102206PR China State Key Laboratory of Silicon Materials Center of Electron MicroscopySchool of Materials Science and EngineeringZhejiang UniversityHangzhou310027PR China MacDiarmid Institute for Advanced Materials and nanotechnology School of Chemical SciencesThe University of AucklandAuckland1142New Zealand MacDiarmid Institute for Advanced Materials and nanotechnology School of Physical and Chemical SciencesUniversity of CanterburyChristchurch8140New Zealand MacDiarmid Institute for Advanced Materials and nanotechnology School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand

The large-scale synthesis of platinum-free electrocatalysts for the oxygen.r.duction.r.action(Orr)remains a grand *** report the large-scale production of stable and active Orr electrocatalysts based on iron,an earth-abundant element.A core–shell zeolitic imidazolate framework–tannic acid coordination polymer composite(ZIF-8@K-TA)was utilized as the catalyst precursor,which was transformed into iron atoms dispersed in hollow porous nitrogen-doped carbon capsules(H-Fe-n_(x)-C)through ion exchange and pyrolysis.H-Fe-n_(x)-C fea-tures site-isolated single-atom iron centers coordinated to nitrogen in graphitic layers,high levels of nitrogen doping,and high permeability to incoming *** from these characteristics,H-Fe-n_(x)-C demonstrated efficient electrocatalytic activity(E_(1/2)=0.92 V,***)and stability towards the Orr in both alkaline and acidic *** Orr performance,it surpassed the majority of recently reported Fe-n-C catalysts and the standard Pt/C *** addition,H-Fe-n_(x)-C showed outstanding tolerance to methanol.

关键词： Metal single atoms Hollow carbon capsules Oxygen.r.duction.r.action Metal–organic framework Electrocatalysis

澳大利亚造山型金矿和侵入岩有关金矿系统流体包裹体资料和矿化过程的比较

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岩石学报 2007年第1期23卷 21-32页

作者： Terry P.Memagh E.n.Bastrakov Khin Zaw A.S.Wygmlak L.A.I.Wybom Geoscience Australia GPO Box 378CanberraACT2601Australia. CODES ArC Cen.r. of Excellence in Ore Deposits University of TasmaniaPrivate Bag 79HobartTAS7001Australia. n.r.hern Territory Geological Survey GPO Box 3000DarwinNT0801Australia.

We have examined the fluid inclusion data and fluid chemistry of Australian orogenic and in.r.sion.r.lated gold deposits to determine if similar min.r.lization processes apply to both styles of *** fluid inclusion data from the Yilgarn craton,the western subprovince of the Lachlan orogen,the Tanami,Tennant Creek and Pine Creek regions,and the telfer gold mine show that min.r.lization involved fluids with broadly similar major chemical components(i.e.H_2O+naCl+CO_2±CH_4±n_2).These deposits formed over a wide range of temperature-pressure conditions(500℃,nity, CO_2-bearing inclusions and low salinity aqueous inclusions occur in both systems but the main difference between these two types of deposits is that most in.r.sion.r.lated gold deposits also contain at least one population of high-salinity aqueous *** and hydrogen isotope data for both styles of deposit usually cannot distinguish between a magmatic or metamorphic source for the ore-bearing ***,sulfur and lead isotope data for the in.r.sion.r.lated gold deposits gen.r.lly indicate either a magmatic source or mixing between magmatic and sedimentary sources of *** metamorphic geothermal gradients associated with in.r.sion.r.lated gold deposits are characterized by low pressure,high temperature metamorphism and high crustal geothermal gradients of>30/*** amphibole breakdown occurs in a granite source region,the spatially related deposits are more commonly associated with Cu-Au deposits rather than Au-only deposits that are associated with lower temperature *** dominant processes thought to cause gold precipitation in both types of deposits are fluid-rock interaction(***)or phase *** of the physical and chemical properties of the H_2O-naCl-CO_2 system on the nature of gold precipitation mechanisms at different crustal levels infers different roles of chemical(fluid-rock interaction)versus rheological(phas

关键词：澳大利亚造山型金矿侵入岩有关金矿系统流体包裹体资料矿化过程