Single-atom Pt catalysts are designed to promote efficient atom utilization,whereas effective decrease of Pt loading and improvement of photocatalytic activity in monoatomic Pt-deposited systems is still ongoing.Atomi...Single-atom Pt catalysts are designed to promote efficient atom utilization,whereas effective decrease of Pt loading and improvement of photocatalytic activity in monoatomic Pt-deposited systems is still ongoing.Atomically dispersed metal species in crystalline carbon nitride are still challenging owing to their high crystallization and structural stability.In this study,we developed a novel single-atomic Pt-Cu catalyst for reducing noble metal loading by combining Pt with earth-abundant Cu atoms and enhancing photocatalytic CO_(2)reduction.N-vacancy-rich crystalline carbon nitride was used as a fine-tuning ligand for isolated Pt-Cu atom dispersion based on its accessible functional N vacancies as the seeded centers.The synthesized dimetal Pt-Cu atoms on crystalline carbon nitride(Pt Cu-cr CN)exhibited high selectivity and activity for CO_(2)conversion without the addition of any cocatalyst or sacrificial agent.In particular,we demonstrated that the diatomic Pt-Cu exhibited high mass activity with only 0.32 wt% Pt loading and showed excellent photocatalytic selectivity toward CH_(4)generation.The mechanism of CO_(2)photoreduction for Pt Cu-cr CN was proposed based on the observations and analysis of aberration-corrected high-angle annular dark-field scanning transmission electron microscopy images,in situ irradiated X-ray photoelectron spectroscopy,and in situ diffuse reflectance infrared Fourier transform spectroscopy.The findings of this work provide insights for abrogating specific bifunctional atomic metal sites in noble metal-based photocatalysts by reducing noble metal loading and maximizing their effective mass activity.展开更多
The title complex [Cu2(bipy)2OAcClOH]TsTausH3H2O(C31H37Cl- Cu2N5O11S2) has been synthesized by the reaction of 2,2?bipyridine(bipy), N-P-tolysulfony taurine (TsTausH) and copper acetate in water-ethanol solution, and ...The title complex [Cu2(bipy)2OAcClOH]TsTausH3H2O(C31H37Cl- Cu2N5O11S2) has been synthesized by the reaction of 2,2?bipyridine(bipy), N-P-tolysulfony taurine (TsTausH) and copper acetate in water-ethanol solution, and its crystal structure was determined by X-ray diffraction method. The crystal belongs to triclinic, space group P with a = 0.74485(14), b = 1.6094(3), c = 1.7472(3) nm, a = 114.662(4), b = 99.997(4), g = 93.218(4), V = 1.8551(6) nm3, Mr = 882.31, Z = 2, Dc = 1.580 g/cm3, m = 1.395 mm-1 and F(000) = 906. The complex is a binuclear copper compound, and the two copper ions nearly have the same coordination environment. There exists MM bond in the complex. The distance of Cu(1)Cu(2) is 0.29747(7) nm. The two ions form two distorted octahedral geometries.展开更多
A new copper complex, Cu2（pba）（bpy）2Cl2·4H2O （here pba was propylenebis （oxamic acid）, bpy was bipyridine）, was synthesized. Crystal structure of the title complex was determined. It belongs to the tetrag...A new copper complex, Cu2（pba）（bpy）2Cl2·4H2O （here pba was propylenebis （oxamic acid）, bpy was bipyridine）, was synthesized. Crystal structure of the title complex was determined. It belongs to the tetragonal system, molecular formula Cu2Cl2O 10N6C 27H 32, Mr=798.58, space group P41212, a=b=9.484（4）, c=35\^918（9）, V=3235（2）3, Dx=1.64gcm -3 and F（000）=1568, μ=1\^546mm -1 for Z=4. The crystal structure was solved by direct methods for final R=0\^048 and Rw=0.060 for 1992 observed reflections with I>3σ（I）. The complex has a C2 symmetry. A chloride anion, two nitrogen atoms from bipyridine and two oxygen atoms from the oxamide carbonyl and carboxyl coordinated to the Cu II ion forming a square pyramidal geometry. In each molecule, two bpy are almost parallel.展开更多
The title complex [Cu2(-dppm)2(-Et2dtc)](ClO4)EtOH0.25H2O (dppm = bis- (diphenylphosphino)methane, Et2dtc = diethyldithiocarbamate) has been synthesized and characterized by single-crystal X-ray diffraction analysis. ...The title complex [Cu2(-dppm)2(-Et2dtc)](ClO4)EtOH0.25H2O (dppm = bis- (diphenylphosphino)methane, Et2dtc = diethyldithiocarbamate) has been synthesized and characterized by single-crystal X-ray diffraction analysis. The crystal structure is of monoclinic, space group C2/c with a = 42.587(1), b = 14.1653(4), c = 20.5649(5) ? = 105.945(1)? V =11928.6 3, C57H60.5ClCu2NO5.25P4S2, Mr = 1194.09, Z = 8, Dc = 1.330 g/cm3, (MoK) = 0.98 mm-1 and F(000) = 4948. A total of 15243 reflections were collected, of which 7322 were unique. The structure was refined to R = 0.0739 and wR = 0.1846 for 5135 observed reflections with I > 2(I). The crystal structure consists of the complex cation [Cu2(-dppm)2(-Et2dtc)]+, anion ClO4- and solvate H2O and EtOH, where the dinuclear Cu(Ⅰ) atoms are bridged doubly by two dppm ligands and singly by Et2dtc to give three five-membered rings. The Cu(Ⅰ) atom is in an approxi- mately trigonal-planar environment with the P2S chromophore. The short Cu贩稢u separation (2.7111 ? suggests the presence of metal-metal contact.展开更多
文摘Single-atom Pt catalysts are designed to promote efficient atom utilization,whereas effective decrease of Pt loading and improvement of photocatalytic activity in monoatomic Pt-deposited systems is still ongoing.Atomically dispersed metal species in crystalline carbon nitride are still challenging owing to their high crystallization and structural stability.In this study,we developed a novel single-atomic Pt-Cu catalyst for reducing noble metal loading by combining Pt with earth-abundant Cu atoms and enhancing photocatalytic CO_(2)reduction.N-vacancy-rich crystalline carbon nitride was used as a fine-tuning ligand for isolated Pt-Cu atom dispersion based on its accessible functional N vacancies as the seeded centers.The synthesized dimetal Pt-Cu atoms on crystalline carbon nitride(Pt Cu-cr CN)exhibited high selectivity and activity for CO_(2)conversion without the addition of any cocatalyst or sacrificial agent.In particular,we demonstrated that the diatomic Pt-Cu exhibited high mass activity with only 0.32 wt% Pt loading and showed excellent photocatalytic selectivity toward CH_(4)generation.The mechanism of CO_(2)photoreduction for Pt Cu-cr CN was proposed based on the observations and analysis of aberration-corrected high-angle annular dark-field scanning transmission electron microscopy images,in situ irradiated X-ray photoelectron spectroscopy,and in situ diffuse reflectance infrared Fourier transform spectroscopy.The findings of this work provide insights for abrogating specific bifunctional atomic metal sites in noble metal-based photocatalysts by reducing noble metal loading and maximizing their effective mass activity.
基金This work was supported by the NSF of Guangxi Province (0339034) and the Science Research Foundation of Guangxi Universities
文摘The title complex [Cu2(bipy)2OAcClOH]TsTausH3H2O(C31H37Cl- Cu2N5O11S2) has been synthesized by the reaction of 2,2?bipyridine(bipy), N-P-tolysulfony taurine (TsTausH) and copper acetate in water-ethanol solution, and its crystal structure was determined by X-ray diffraction method. The crystal belongs to triclinic, space group P with a = 0.74485(14), b = 1.6094(3), c = 1.7472(3) nm, a = 114.662(4), b = 99.997(4), g = 93.218(4), V = 1.8551(6) nm3, Mr = 882.31, Z = 2, Dc = 1.580 g/cm3, m = 1.395 mm-1 and F(000) = 906. The complex is a binuclear copper compound, and the two copper ions nearly have the same coordination environment. There exists MM bond in the complex. The distance of Cu(1)Cu(2) is 0.29747(7) nm. The two ions form two distorted octahedral geometries.
文摘A new copper complex, Cu2（pba）（bpy）2Cl2·4H2O （here pba was propylenebis （oxamic acid）, bpy was bipyridine）, was synthesized. Crystal structure of the title complex was determined. It belongs to the tetragonal system, molecular formula Cu2Cl2O 10N6C 27H 32, Mr=798.58, space group P41212, a=b=9.484（4）, c=35\^918（9）, V=3235（2）3, Dx=1.64gcm -3 and F（000）=1568, μ=1\^546mm -1 for Z=4. The crystal structure was solved by direct methods for final R=0\^048 and Rw=0.060 for 1992 observed reflections with I>3σ（I）. The complex has a C2 symmetry. A chloride anion, two nitrogen atoms from bipyridine and two oxygen atoms from the oxamide carbonyl and carboxyl coordinated to the Cu II ion forming a square pyramidal geometry. In each molecule, two bpy are almost parallel.
基金Supported by the Government of Guangdong province
文摘The title complex [Cu2(-dppm)2(-Et2dtc)](ClO4)EtOH0.25H2O (dppm = bis- (diphenylphosphino)methane, Et2dtc = diethyldithiocarbamate) has been synthesized and characterized by single-crystal X-ray diffraction analysis. The crystal structure is of monoclinic, space group C2/c with a = 42.587(1), b = 14.1653(4), c = 20.5649(5) ? = 105.945(1)? V =11928.6 3, C57H60.5ClCu2NO5.25P4S2, Mr = 1194.09, Z = 8, Dc = 1.330 g/cm3, (MoK) = 0.98 mm-1 and F(000) = 4948. A total of 15243 reflections were collected, of which 7322 were unique. The structure was refined to R = 0.0739 and wR = 0.1846 for 5135 observed reflections with I > 2(I). The crystal structure consists of the complex cation [Cu2(-dppm)2(-Et2dtc)]+, anion ClO4- and solvate H2O and EtOH, where the dinuclear Cu(Ⅰ) atoms are bridged doubly by two dppm ligands and singly by Et2dtc to give three five-membered rings. The Cu(Ⅰ) atom is in an approxi- mately trigonal-planar environment with the P2S chromophore. The short Cu贩稢u separation (2.7111 ? suggests the presence of metal-metal contact.
