Polyhedron lead hydroxide carbonate （2PbCO3·Pb（OH）2 ） microcrystals have been prepared in solution phase via a facile method in the presence of surfactant cetyltrimethylammonium bromide （CTAB）. All the samp...Polyhedron lead hydroxide carbonate （2PbCO3·Pb（OH）2 ） microcrystals have been prepared in solution phase via a facile method in the presence of surfactant cetyltrimethylammonium bromide （CTAB）. All the samples were characterized by powder X-ray diffraction ,pattern （XRD）, field-emission scanning electron mi- croscopy （FE-SEM）, high-resolution transmission electron microscopy （HRTEM）, and selected area electron diffraction （SAED）. The possible growth mechanism was discussed. 2PbCO3·Pb（OH）2 microcrystals were found to be a novel and efficient catalyst for the synthesis of diphenyl carbonate （DPC） by transesterification of dimethyl carbonate （DMC） with phenol. Compared with some other catalysts, such as AlCl3, ZnCl2, and Mg5（CO3）4（OH）2, 2PbCO3·Pb（OH）2 microcrystals are stable and show relatively high activity at low catalyst amount. When the reaction was carried out at 180 12, with a molar ratio of phenol to DMC of 2：1, a reaction time 14 h, and a catalyst amount 0.2% （molar ratio to phenol）, the selectivity of DPC and methyl phenyl carbonate （MPC） was 14.7% and 78.8%, respectively.展开更多
The syntheses of a new type of heteromacrocyclic polyether- 2,3-benzo-1,4,7,13-tetraoxa-10-telluracyclopentadeca-2-ene(L),and its pla- tinum complex(PtL_2Cl_2)were described.The catalytic activity of this complex for ...The syntheses of a new type of heteromacrocyclic polyether- 2,3-benzo-1,4,7,13-tetraoxa-10-telluracyclopentadeca-2-ene(L),and its pla- tinum complex(PtL_2Cl_2)were described.The catalytic activity of this complex for the hydrosilylation of olefins by triethoxysilane was investigated.展开更多
The title complex (PtL_2Cl_2) was synthesized by reacting 10-selenabenzo-15-crown-5 (L) with potassium chloroplatinite. Its catalytic activity for the hydrosilylation of olefins by triethoxysilane, was investi gated.
Monodisperse CoPh nanocrystals （NCs） have been synthesized in oleylamine solution by an organic solvothermal method. The NCs were ellipsoidal particles with a diameter around 6.6 nm and length around 10 nm with a go...Monodisperse CoPh nanocrystals （NCs） have been synthesized in oleylamine solution by an organic solvothermal method. The NCs were ellipsoidal particles with a diameter around 6.6 nm and length around 10 nm with a good single crystal structure. Using CoPt3 NCs as catalysts, large-area boron nanowires with diameters ranging from 30 to 50 nm were successfully prepared by chemical vapor deposition using a C/B/B203 mixture as the precursor. Structural analysis indicated that these nanowires were single crystalline with a fl-rhombohedral structure. Measurement of the field emission properties of boron nanowire films showed that the boron nanowires have good field emission characteristics.展开更多
The electronic structure of tungsten carbide was investigated by EHMO semiempirical me- thod.The most stable structure of the carbide was predicted on the basis of binding energy calcula- tions.The W-C bonding is cova...The electronic structure of tungsten carbide was investigated by EHMO semiempirical me- thod.The most stable structure of the carbide was predicted on the basis of binding energy calcula- tions.The W-C bonding is covalent in nature with some charge transfer from the W to the C atoms. The increase in the occupancy of the d shell of the W atoms and the position of the Fermi level may account for the platinum-like catalytic behavior of tungsten carbide.展开更多
Studies on ultrafine particle catalyst have attracted many researchers' attention by its large surface area,higher activity and selectivity.Based on the mechanism of α-Fe and Fe_xC_y as the catalytical active spe...Studies on ultrafine particle catalyst have attracted many researchers' attention by its large surface area,higher activity and selectivity.Based on the mechanism of α-Fe and Fe_xC_y as the catalytical active species this paper reports for the first time the preparation method of Fe_3C ultrafine parti- cle catalyst,from highly dispersed amorphous Fe powder and free carbon.The Fe powder and free car- bon,prepared by laser pyrolysis technique,was then treated by washing and heating at high tempera- ture protected with N_2.The catalyst prepared under different experimental conditions was characterazed by means of XRD,electronic diffraction and TEM.It shows that the crystlline grain size is in a range of 1-4nm and composed of Fe_3C and α-Fe.It has been found that the ultrafine particle iron-carbonide catalyst exhibited much higher activity and selectivity to light olefins.At the standard atmosphere and 380℃ reaction temperature,the conversion of CO reached a maximum of 80%.展开更多
Iodine is widely used in aqueous zinc batteries(ZBs)due to its abundant resources,low cost,and active redox reactions.In addition to the active material in zinc-iodine batteries,iodine also plays an important role in ...Iodine is widely used in aqueous zinc batteries(ZBs)due to its abundant resources,low cost,and active redox reactions.In addition to the active material in zinc-iodine batteries,iodine also plays an important role in other ZBs,such as regulating the electrochemical behavior of zinc ions,promoting the reaction kinetic and reversibility of other redox pairs,catalytic behaviors related to iodine reactions,coupling with other halogen ions,shuttle behaviors of polyiodides,etc.However,there is currently a lack of comprehensive discussion on these aspects.Here,this review provides a comprehensive overview of the electrochemical behaviors of iodide in the aqueous ZBs.The effect of iodine ions on the Zn^(2+)desolvation behaviors and the interfacial behaviors of Zn anode was summarized.Iodine redox pairs boosting other redox pairs,such as MnO_(2)/Mn^(2+)redox pair and vanadium redox pair to obtain high reversibility and capacity was also discussed.Moreover,the catalytic behaviors related to iodine reactions in aqueous ZBs,synergistic reaction with other halogen ions and suppression of shuttle behaviors for high performance zinc-iodine batteries were systematically analyzed.Finally,future prospects for designing effective iodine electrochemical behaviors with practicability are proposed,which will provide scientific guidance for the practical application of iodine-related aqueous ZBs.展开更多
基金Sponsored by the National Natural Science Foundation of China (20671011,20331010,90406002 and 90406024)"111"Project (B07012) Key Laboratory of Structural Chemistry Foundation,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences(060017)
文摘Polyhedron lead hydroxide carbonate （2PbCO3·Pb（OH）2 ） microcrystals have been prepared in solution phase via a facile method in the presence of surfactant cetyltrimethylammonium bromide （CTAB）. All the samples were characterized by powder X-ray diffraction ,pattern （XRD）, field-emission scanning electron mi- croscopy （FE-SEM）, high-resolution transmission electron microscopy （HRTEM）, and selected area electron diffraction （SAED）. The possible growth mechanism was discussed. 2PbCO3·Pb（OH）2 microcrystals were found to be a novel and efficient catalyst for the synthesis of diphenyl carbonate （DPC） by transesterification of dimethyl carbonate （DMC） with phenol. Compared with some other catalysts, such as AlCl3, ZnCl2, and Mg5（CO3）4（OH）2, 2PbCO3·Pb（OH）2 microcrystals are stable and show relatively high activity at low catalyst amount. When the reaction was carried out at 180 12, with a molar ratio of phenol to DMC of 2：1, a reaction time 14 h, and a catalyst amount 0.2% （molar ratio to phenol）, the selectivity of DPC and methyl phenyl carbonate （MPC） was 14.7% and 78.8%, respectively.
文摘The syntheses of a new type of heteromacrocyclic polyether- 2,3-benzo-1,4,7,13-tetraoxa-10-telluracyclopentadeca-2-ene(L),and its pla- tinum complex(PtL_2Cl_2)were described.The catalytic activity of this complex for the hydrosilylation of olefins by triethoxysilane was investigated.
文摘The title complex (PtL_2Cl_2) was synthesized by reacting 10-selenabenzo-15-crown-5 (L) with potassium chloroplatinite. Its catalytic activity for the hydrosilylation of olefins by triethoxysilane, was investi gated.
基金Acknowledgements The project was supported by the Natural Science Foundation of China （Grant Nos. 50872147, U0734003）, and the National ＂863＂ （No. 2007AA03Z305） and ＂973＂ （No. 2007CB935503） Projects of the Ministry of Science and Technology of China.
文摘Monodisperse CoPh nanocrystals （NCs） have been synthesized in oleylamine solution by an organic solvothermal method. The NCs were ellipsoidal particles with a diameter around 6.6 nm and length around 10 nm with a good single crystal structure. Using CoPt3 NCs as catalysts, large-area boron nanowires with diameters ranging from 30 to 50 nm were successfully prepared by chemical vapor deposition using a C/B/B203 mixture as the precursor. Structural analysis indicated that these nanowires were single crystalline with a fl-rhombohedral structure. Measurement of the field emission properties of boron nanowire films showed that the boron nanowires have good field emission characteristics.
基金This project was supported by the National Natural Science Foundation of China.
文摘The electronic structure of tungsten carbide was investigated by EHMO semiempirical me- thod.The most stable structure of the carbide was predicted on the basis of binding energy calcula- tions.The W-C bonding is covalent in nature with some charge transfer from the W to the C atoms. The increase in the occupancy of the d shell of the W atoms and the position of the Fermi level may account for the platinum-like catalytic behavior of tungsten carbide.
基金The project was supported by the National Natural Science Foundation of China.
文摘Studies on ultrafine particle catalyst have attracted many researchers' attention by its large surface area,higher activity and selectivity.Based on the mechanism of α-Fe and Fe_xC_y as the catalytical active species this paper reports for the first time the preparation method of Fe_3C ultrafine parti- cle catalyst,from highly dispersed amorphous Fe powder and free carbon.The Fe powder and free car- bon,prepared by laser pyrolysis technique,was then treated by washing and heating at high tempera- ture protected with N_2.The catalyst prepared under different experimental conditions was characterazed by means of XRD,electronic diffraction and TEM.It shows that the crystlline grain size is in a range of 1-4nm and composed of Fe_3C and α-Fe.It has been found that the ultrafine particle iron-carbonide catalyst exhibited much higher activity and selectivity to light olefins.At the standard atmosphere and 380℃ reaction temperature,the conversion of CO reached a maximum of 80%.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(Grant No.2023D01C168)Scientific Research Program of the Higher Education Institution of Xinjiang(Grant No.XJEDU2022P001)+1 种基金Autonomous Region"Tianchi Talent"Introduction Program Youth Doctoral Program(Grant No.51052401544)Tianshan Innovation Team Program of Xinjiang Uygur Autonomous Region(Grant No.2023D14001).
文摘Iodine is widely used in aqueous zinc batteries(ZBs)due to its abundant resources,low cost,and active redox reactions.In addition to the active material in zinc-iodine batteries,iodine also plays an important role in other ZBs,such as regulating the electrochemical behavior of zinc ions,promoting the reaction kinetic and reversibility of other redox pairs,catalytic behaviors related to iodine reactions,coupling with other halogen ions,shuttle behaviors of polyiodides,etc.However,there is currently a lack of comprehensive discussion on these aspects.Here,this review provides a comprehensive overview of the electrochemical behaviors of iodide in the aqueous ZBs.The effect of iodine ions on the Zn^(2+)desolvation behaviors and the interfacial behaviors of Zn anode was summarized.Iodine redox pairs boosting other redox pairs,such as MnO_(2)/Mn^(2+)redox pair and vanadium redox pair to obtain high reversibility and capacity was also discussed.Moreover,the catalytic behaviors related to iodine reactions in aqueous ZBs,synergistic reaction with other halogen ions and suppression of shuttle behaviors for high performance zinc-iodine batteries were systematically analyzed.Finally,future prospects for designing effective iodine electrochemical behaviors with practicability are proposed,which will provide scientific guidance for the practical application of iodine-related aqueous ZBs.
