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Na_4Sn_9与一些配合物相互作用的^(119)Sn和^(23)Na NMR研究
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作者 汪信 杨绪杰 +3 位作者 陆路德 宋启泽 王文哲 顾蔚红 《无机化学学报》 SCIE CAS CSCD 北大核心 1992年第1期62-64,共3页
以^(199)Sn和^(23)Na核磁共振研究了Na_4Sn_9-乙二胺体系中加入M(acacen)(M=Cu^(2+),Ni^(2+))和Ln(fod)_3(Ln=Pr^(3+),Yb^(3+),Eu^(3+))后的化学位移和偶合常数。结果表明,假接触和体积磁化率的变化是引起化学位移变化的主要原因,而Ferm... 以^(199)Sn和^(23)Na核磁共振研究了Na_4Sn_9-乙二胺体系中加入M(acacen)(M=Cu^(2+),Ni^(2+))和Ln(fod)_3(Ln=Pr^(3+),Yb^(3+),Eu^(3+))后的化学位移和偶合常数。结果表明,假接触和体积磁化率的变化是引起化学位移变化的主要原因,而Fermi接触的贡献可以忽略。 展开更多
关键词 Zintl离子 络合物 假接触 锡化钠
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PtSnNa/SUZ-4:An efficient catalyst for propane dehydrogenation 被引量:9
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作者 周华兰 龚静静 +4 位作者 许波连 邓生财 丁元华 俞磊 范以宁 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第3期529-536,共8页
The structure and catalytic properties of PtSn catalysts supported on SUZ-4 and ZSM-5 zeolite have been studied by using various experimental techniques including XRD,nitrogen adsorption,NH3-TPD,TG,H2-TPR and TPO tech... The structure and catalytic properties of PtSn catalysts supported on SUZ-4 and ZSM-5 zeolite have been studied by using various experimental techniques including XRD,nitrogen adsorption,NH3-TPD,TG,H2-TPR and TPO techniques combined with propane dehydrogenation tests.It has been shown that SUZ-4-supported PtSnNa(PtSnNa/SUZ-4) was determined to be a better catalyst for propane dehydrogenation than conventional catalysts supported on ZSM-5,owing to its higher catalytic activity and stability.Dibenzothiophene poisoning experiments were performed to investigate the detailed structures of the two supported catalysts.The characterization of the two catalysts indicates that the distribution of Pt on the porous support affects the activity.In contrast to ZSM-5-supported catalysts,Pt particles on the PtSnNa/SUZ-4 are primarily dispersed over the external surface and are not as readily deactivated by carbon deposition.This is because that the strong acid sites of the SUZ-4 zeolite evidently prevented the impregnation of the Pt precursor H_2PtCl_6 into the zeolite.In contrast,the weak acid sites of the ZSM-5 zeolite led to more of the precursor entering the zeolite tunnels,followed by transformation to highly dispersed Pt clusters during calcination.In the case of the PtSnNa/ZSM-5,the interactions between Sn oxides and the support were lessened,owing to the weaker acidity of the ZSM-5 zeolite.The dispersed Sn oxides were therefore easier to reduce to the metallic state,thus decreasing the catalytic activity for hydrocarbon dehydrogenation. 展开更多
关键词 SUZ-4 zeolite PtSnNa catalyst Propane dehydrogenation Catalyst stability Pt distribution
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Effect of NaOH treatment on combustion performance of Xilinhaote lignite 被引量:5
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作者 Liu Xiangchun Feng Li +2 位作者 Song Lingling Wang Xinhua Zhang Ying 《International Journal of Mining Science and Technology》 SCIE EI 2014年第1期51-55,共5页
The combustion characteristics of NaOH treated and untreated Xilihaote lignite was investigated by thermogravimetric analysis.The relationship between physico-chemical properties,including the ash content,oxygen-conta... The combustion characteristics of NaOH treated and untreated Xilihaote lignite was investigated by thermogravimetric analysis.The relationship between physico-chemical properties,including the ash content,oxygen-containing functional groups,mean pore diameter and specific surface area and combustion performance,was also studied in this paper.Combustion kinetic parameters were calculated through Coasts Redfern Method.The results show that ignition of treated samples takes place at higher temperature compared to raw lignite,and peak temperature also occurs at higher temperature.The maximum combustion rate of the sample,which was treated by 0.01 mol/L NaOH lignite,was the biggest.Reaction orders of 0.6,2.0,and 0.8 were found to be effective mechanism for definite three temperature regions.Average activation energies of these three temperature regions of XLHTR,XLHT0.01,XLHT0.50 and XLTH1.00 are 19.17,23.87,10.77,and 10.93 kJ/mol,respectively.Treatment of lignite with NaOH can reduce the reactivity of lignite at proper concentration. 展开更多
关键词 Lignite Alkali treatment Non-isothermal thermogravimetry Combustion performance
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