metol-free Robson -type macrocycle was synthesized for first time by proton-templation and from that the metal complexes were prepared.By X-ray study the structure of Ni(Ⅱ)-complex was characterized.
A coordination complex was synthesized from NiCl2 and dipeptide glycylglycine（GG）. It was characterized by element analysis, NMR and TG methods, and then was determined to be Ni（C4HsN2O3）2Cl2. Using an isoperiboli...A coordination complex was synthesized from NiCl2 and dipeptide glycylglycine（GG）. It was characterized by element analysis, NMR and TG methods, and then was determined to be Ni（C4HsN2O3）2Cl2. Using an isoperibolic reaction calorimeter, the standard molar enthalpy of formation of Ni（GG）2Cl2（solid） has been determined to be -（1 674.66±2.02） kJ · mol^-1 at 298.15 K.展开更多
A novel two-dimensional compound [Ni0.5(H2O)1.5{Ni(en)2}3V18O42(Cl)]3.5H2O 1 has been hydrothermally synthesized and characterized by IR, elemental analysis, and single-crystal X-ray diffraction analysis. Crystal data...A novel two-dimensional compound [Ni0.5(H2O)1.5{Ni(en)2}3V18O42(Cl)]3.5H2O 1 has been hydrothermally synthesized and characterized by IR, elemental analysis, and single-crystal X-ray diffraction analysis. Crystal data for 1: monoclinic, space group C2/c with a = 12.824(3), b = 27.873(6), c = 21.092(4) , b = 92.93(3), V = 7529(3) 3, Z = 4, Dc = 2.012 g/cm3, Mr = 2280.56, F(000) = 4476 and m = 3.092 mm-1. The final R and wR are 0.0769 and 0.1783, respectively for 4203 observed reflections with I>2s(I). The structure consists of [V18O42(Cl)]7- clusters linked by trans- {Ni(en)2} groups into linear chains, while cis-{Ni(en)2} groups provide the cross-linking adjacent chains to form a two-dimensional structure.展开更多
以二苯基-1-甲基咪唑膦(dpim)为配体制备了一种新型的配合物催化剂Ni(dpim)_2Cl_2.循环伏安研究表明,Ni(dpim)2Cl2配合物在氮气气氛下表现出两步还原的电化学行为,在-0.7 V下为两电子的不可逆还原,在-1.3 V下为单电子准可逆还原.向电解...以二苯基-1-甲基咪唑膦(dpim)为配体制备了一种新型的配合物催化剂Ni(dpim)_2Cl_2.循环伏安研究表明,Ni(dpim)2Cl2配合物在氮气气氛下表现出两步还原的电化学行为,在-0.7 V下为两电子的不可逆还原,在-1.3 V下为单电子准可逆还原.向电解液中通入CO_2后,在-1.3 V下的还原峰变得不可逆,且其峰电流从0.48 m A·cm^(-2)增大到0.55 m A·cm^(-2).在质子源(CH3OH)存在的条件下,该还原峰电流可继续增大到0.72 m A·cm^(-2).该研究结果表明,Ni(dpim)_2Cl_2配合物对CO_2还原具有良好的电催化性能,且其电催化还原过程符合ECE机理.在-1.3 V下恒电位电解得到的还原产物主要为CO,催化转换频率(Turnover of Frenquency,TOF)为0.17 s^(-1).展开更多
Single-atomic transition metal-nitrogen codoped carbon(M-N-C)are efficient substitute catalysts for noble metals to catalyze the electrochemical CO_(2) reduction reaction(CO_(2)RR).However,the uncontrolled aggregation...Single-atomic transition metal-nitrogen codoped carbon(M-N-C)are efficient substitute catalysts for noble metals to catalyze the electrochemical CO_(2) reduction reaction(CO_(2)RR).However,the uncontrolled aggregations of metal and serious loss of nitrogen species constituting the M-N_(x) active sites are frequently observed in the commonly used pyrolysis procedure.Herein,single-atomic nickel(Ni)-based sheet-like electrocatalysts with abundant Ni-N_(4) active sites were created by using a novel ammonium chloride(NH_(4)Cl)-assited pyrolysis method.Spherical aberration correction electron microscopy and X-ray absorption fine structure analysis clearly revealed that Ni species are atomically dispersed and anchored by N in Ni-N_(4) structure.The addition of NH_(4)Cl optimized the mesopore size to 7-10 nm and increased the concentrations of pyridinic N(3.54 wt%)and Ni-N_(4)(3.33 wt%)species.The synergistic catalytic effect derived from Ni-N_(4) active sites and pyridinic N species achieved an outstanding CO_(2) RR performance,presenting a high CO Faradaic efficiency(FE_(CO))up to 98% and a large CO partial current density of 8.5 mA cm^(-2) at a low potential of-0.62 V vs.RHE.Particularly,the FE_(CO) maintains above 80% within a large potential range from -0.43 to -0.73 V vs.RHE.This work provides a practical and feasible approach to building highly active single-atomic catalysts for CO_(2) conversion systems.展开更多
文摘metol-free Robson -type macrocycle was synthesized for first time by proton-templation and from that the metal complexes were prepared.By X-ray study the structure of Ni(Ⅱ)-complex was characterized.
基金Supported by the National Natural Science Foundation of China (20373050).
文摘A coordination complex was synthesized from NiCl2 and dipeptide glycylglycine（GG）. It was characterized by element analysis, NMR and TG methods, and then was determined to be Ni（C4HsN2O3）2Cl2. Using an isoperibolic reaction calorimeter, the standard molar enthalpy of formation of Ni（GG）2Cl2（solid） has been determined to be -（1 674.66±2.02） kJ · mol^-1 at 298.15 K.
基金This work was supported by NNSFC (No. 20271050 and 20171045) the Educational Ministry of China the Talents Program of the Chinese Academy of Sciences and NSF of Fujian province (E0210029)
文摘A novel two-dimensional compound [Ni0.5(H2O)1.5{Ni(en)2}3V18O42(Cl)]3.5H2O 1 has been hydrothermally synthesized and characterized by IR, elemental analysis, and single-crystal X-ray diffraction analysis. Crystal data for 1: monoclinic, space group C2/c with a = 12.824(3), b = 27.873(6), c = 21.092(4) , b = 92.93(3), V = 7529(3) 3, Z = 4, Dc = 2.012 g/cm3, Mr = 2280.56, F(000) = 4476 and m = 3.092 mm-1. The final R and wR are 0.0769 and 0.1783, respectively for 4203 observed reflections with I>2s(I). The structure consists of [V18O42(Cl)]7- clusters linked by trans- {Ni(en)2} groups into linear chains, while cis-{Ni(en)2} groups provide the cross-linking adjacent chains to form a two-dimensional structure.
文摘以二苯基-1-甲基咪唑膦(dpim)为配体制备了一种新型的配合物催化剂Ni(dpim)_2Cl_2.循环伏安研究表明,Ni(dpim)2Cl2配合物在氮气气氛下表现出两步还原的电化学行为,在-0.7 V下为两电子的不可逆还原,在-1.3 V下为单电子准可逆还原.向电解液中通入CO_2后,在-1.3 V下的还原峰变得不可逆,且其峰电流从0.48 m A·cm^(-2)增大到0.55 m A·cm^(-2).在质子源(CH3OH)存在的条件下,该还原峰电流可继续增大到0.72 m A·cm^(-2).该研究结果表明,Ni(dpim)_2Cl_2配合物对CO_2还原具有良好的电催化性能,且其电催化还原过程符合ECE机理.在-1.3 V下恒电位电解得到的还原产物主要为CO,催化转换频率(Turnover of Frenquency,TOF)为0.17 s^(-1).
基金financially supported by the National Natural Science Foundation of China(Nos.21571159 and U1704256)the Natural Science Foundation of Henan Province,China(No.212300410299)the Doctoral Research Fund of Zhengzhou University of Light Industry(No.2018BSJJ024).
文摘Single-atomic transition metal-nitrogen codoped carbon(M-N-C)are efficient substitute catalysts for noble metals to catalyze the electrochemical CO_(2) reduction reaction(CO_(2)RR).However,the uncontrolled aggregations of metal and serious loss of nitrogen species constituting the M-N_(x) active sites are frequently observed in the commonly used pyrolysis procedure.Herein,single-atomic nickel(Ni)-based sheet-like electrocatalysts with abundant Ni-N_(4) active sites were created by using a novel ammonium chloride(NH_(4)Cl)-assited pyrolysis method.Spherical aberration correction electron microscopy and X-ray absorption fine structure analysis clearly revealed that Ni species are atomically dispersed and anchored by N in Ni-N_(4) structure.The addition of NH_(4)Cl optimized the mesopore size to 7-10 nm and increased the concentrations of pyridinic N(3.54 wt%)and Ni-N_(4)(3.33 wt%)species.The synergistic catalytic effect derived from Ni-N_(4) active sites and pyridinic N species achieved an outstanding CO_(2) RR performance,presenting a high CO Faradaic efficiency(FE_(CO))up to 98% and a large CO partial current density of 8.5 mA cm^(-2) at a low potential of-0.62 V vs.RHE.Particularly,the FE_(CO) maintains above 80% within a large potential range from -0.43 to -0.73 V vs.RHE.This work provides a practical and feasible approach to building highly active single-atomic catalysts for CO_(2) conversion systems.
