Underpotential deposition(UPD) of Cu on an Au electrode followed by redox replacement reaction(RRR) of CuUPD with a Pt source(H2PtCl6 or K2PtCl4) yielded Au-supported Pt adlayers(for short,Pt(CuUPD-Pt4+)n/Au for H2PtC...Underpotential deposition(UPD) of Cu on an Au electrode followed by redox replacement reaction(RRR) of CuUPD with a Pt source(H2PtCl6 or K2PtCl4) yielded Au-supported Pt adlayers(for short,Pt(CuUPD-Pt4+)n/Au for H2PtCl6,or Pt(CuUPD-Pt2+)n/Au for K2PtCl4,where n denotes the number of UPD-redox replacement cycles).The electrochemical quartz crystal microbalance(EQCM) technique was used for the first time to quantitatively study the fabricated electrodes and estimate their mass-normalized specific electrocatalytic activity(SECA) for methanol oxidation in alkaline solution.In comparison with Pt(CuUPD-Pt2+)n/Au,Pt(CuUPD-Pt4+)n/Au exhibited a higher electrocatalytic activity,and the maximum SECA was obtained to be as high as 35.7 mA ?g?1 at Pt(CuUPD-Pt4+)3/Au.The layer-by-layer architecture of Pt atoms on Au is briefly discussed based on the EQCM-revealed redox replacement efficiency,and the calculated distribution percentages of bare Au sites agree with the experimental results deduced from the charge under the AuOx-reduction peaks.The EQCM is highly recommended as an efficient technique to quantitatively examine various electrode-supported catalyst adlayers,and the highly efficient catalyst adlayers of noble metals are promising in electrocatalysis relevant to biological,energy and environmental sciences and technologies.展开更多
Heterodimetallic[Cu^(Ⅱ)Fe^(Ⅲ)]one-dimensional(1D)coordination polymers{NH_(4)[{Cu(bpy)}_(2)(C_(2)O_(4))Fe(C_(2)O_(4))_(3)]·H_(2)O}_(n)(1)and{K[{Cu(bpy)}_(2)(C_(2)O_(4))Fe(C_(2)O_(4))_(3)]·H_(2)O}_(n)(_(2))...Heterodimetallic[Cu^(Ⅱ)Fe^(Ⅲ)]one-dimensional(1D)coordination polymers{NH_(4)[{Cu(bpy)}_(2)(C_(2)O_(4))Fe(C_(2)O_(4))_(3)]·H_(2)O}_(n)(1)and{K[{Cu(bpy)}_(2)(C_(2)O_(4))Fe(C_(2)O_(4))_(3)]·H_(2)O}_(n)(_(2))(bpy=2,2’-bipyridine)were obtained using a building block approach by a layering technique,from the reaction of an aqueous solution of[Fe(C_(2)O_(4))_(3)]^(3-)and methanol solutions containing Cu_(2)+and bpy.展开更多
ZIF-67@Co-LDH yolk-shell heterostructures are successfully synthesized by successive increase in Co^(2+)concentration in the methanolic solution of Co^(2+)and 2-methylimidazole(Hmim).This is mainly attributed to the s...ZIF-67@Co-LDH yolk-shell heterostructures are successfully synthesized by successive increase in Co^(2+)concentration in the methanolic solution of Co^(2+)and 2-methylimidazole(Hmim).This is mainly attributed to the slight difference in thermodynamic stability between ZIF-67 and Co-LDHs,accounting for the selective generation of Co-LDHs at a high molar ratio of Co^(2+)to Hmim.展开更多
Although metal-organic frameworks(MOFs)can be extensively used as sacrificial templates to prepare their inorganic counterparts and vice versa,selective generation of these two types of materials in the same synthetic...Although metal-organic frameworks(MOFs)can be extensively used as sacrificial templates to prepare their inorganic counterparts and vice versa,selective generation of these two types of materials in the same synthetic media is seldom involved due to the tremendous difference in composites and their thermodynamic stability.Herein,cobalt layered double hydroxides(Co-LDHs)were successfully prepared at room temperature from a typical synthetic system of zeolitic imidazolate framework-67(ZIF-67),a methanolic solution of Co^(2+)and 2-methyimidazole(Hmim).The final products from ZIF-67 to ZIF-67/Co-LDH hybrids to Co-LDHs were easily regulated while gradually increasing the concentration of Co^(2+)and Hmim or the molar ratio of Co^(2+)/Hmim.There was a similar variation trend in the methanol solvent used as well.The synthetic strategy even can be expanded to the selective synthesis of hetero-bimetallic CoZn-/CoNi-ZIFs and CoZn-/CoNi-LDHs.展开更多
基金supported by the National Natural Science Foundation of China (20675029 & 90713018)the State Special Scientific Project on Water Treatment (2009ZX07212-001-06)
文摘Underpotential deposition(UPD) of Cu on an Au electrode followed by redox replacement reaction(RRR) of CuUPD with a Pt source(H2PtCl6 or K2PtCl4) yielded Au-supported Pt adlayers(for short,Pt(CuUPD-Pt4+)n/Au for H2PtCl6,or Pt(CuUPD-Pt2+)n/Au for K2PtCl4,where n denotes the number of UPD-redox replacement cycles).The electrochemical quartz crystal microbalance(EQCM) technique was used for the first time to quantitatively study the fabricated electrodes and estimate their mass-normalized specific electrocatalytic activity(SECA) for methanol oxidation in alkaline solution.In comparison with Pt(CuUPD-Pt2+)n/Au,Pt(CuUPD-Pt4+)n/Au exhibited a higher electrocatalytic activity,and the maximum SECA was obtained to be as high as 35.7 mA ?g?1 at Pt(CuUPD-Pt4+)3/Au.The layer-by-layer architecture of Pt atoms on Au is briefly discussed based on the EQCM-revealed redox replacement efficiency,and the calculated distribution percentages of bare Au sites agree with the experimental results deduced from the charge under the AuOx-reduction peaks.The EQCM is highly recommended as an efficient technique to quantitatively examine various electrode-supported catalyst adlayers,and the highly efficient catalyst adlayers of noble metals are promising in electrocatalysis relevant to biological,energy and environmental sciences and technologies.
基金supported by the Croatian Science Foundation(Project No.IP-2014-09-4079 and UIP-2014-09-8276)Croatian-French bilateral project.F.T.and D.Packnowledge the support of project CeNIKS co-financed by the Croatian Government and the European Union through the European Regional Development Fund-Competitiveness and Cohesion Operational Programme(Grant KK.01.1.1.02.0013).
文摘Heterodimetallic[Cu^(Ⅱ)Fe^(Ⅲ)]one-dimensional(1D)coordination polymers{NH_(4)[{Cu(bpy)}_(2)(C_(2)O_(4))Fe(C_(2)O_(4))_(3)]·H_(2)O}_(n)(1)and{K[{Cu(bpy)}_(2)(C_(2)O_(4))Fe(C_(2)O_(4))_(3)]·H_(2)O}_(n)(_(2))(bpy=2,2’-bipyridine)were obtained using a building block approach by a layering technique,from the reaction of an aqueous solution of[Fe(C_(2)O_(4))_(3)]^(3-)and methanol solutions containing Cu_(2)+and bpy.
基金support from the National Natural Science Foundation of China(Grant No.21671030)the Key Program of the National Natural Science Foundation of China(Grant No.21531001).
文摘ZIF-67@Co-LDH yolk-shell heterostructures are successfully synthesized by successive increase in Co^(2+)concentration in the methanolic solution of Co^(2+)and 2-methylimidazole(Hmim).This is mainly attributed to the slight difference in thermodynamic stability between ZIF-67 and Co-LDHs,accounting for the selective generation of Co-LDHs at a high molar ratio of Co^(2+)to Hmim.
基金the financial support from the National Natural Science Foundation of China(Grant No.21671030)the Key Program of the National Natural Science Foundation of China(Grant No.21531001)the 111 Project(Grant No.B16008).
文摘Although metal-organic frameworks(MOFs)can be extensively used as sacrificial templates to prepare their inorganic counterparts and vice versa,selective generation of these two types of materials in the same synthetic media is seldom involved due to the tremendous difference in composites and their thermodynamic stability.Herein,cobalt layered double hydroxides(Co-LDHs)were successfully prepared at room temperature from a typical synthetic system of zeolitic imidazolate framework-67(ZIF-67),a methanolic solution of Co^(2+)and 2-methyimidazole(Hmim).The final products from ZIF-67 to ZIF-67/Co-LDH hybrids to Co-LDHs were easily regulated while gradually increasing the concentration of Co^(2+)and Hmim or the molar ratio of Co^(2+)/Hmim.There was a similar variation trend in the methanol solvent used as well.The synthetic strategy even can be expanded to the selective synthesis of hetero-bimetallic CoZn-/CoNi-ZIFs and CoZn-/CoNi-LDHs.
