采用化学沉淀法,并通过进一步的水热反应,制备得到纳米二氧化锡颗粒,通过TEM分析知纳米二氧化锡颗粒的粒径约为5 nm;通过2,4-二羟基苯甲酸和甲醛之间的缩合反应,在体系中加入纳米二氧化锡颗粒,再通过水洗和热处理等步骤制备了纳米SnO_2/...采用化学沉淀法,并通过进一步的水热反应,制备得到纳米二氧化锡颗粒,通过TEM分析知纳米二氧化锡颗粒的粒径约为5 nm;通过2,4-二羟基苯甲酸和甲醛之间的缩合反应,在体系中加入纳米二氧化锡颗粒,再通过水洗和热处理等步骤制备了纳米SnO_2/C碳包覆微球,控制加入二氧化锡纳米颗粒的质量制备了不同样品来探究其对材料形貌及性能的影响。研究表明,当添加纳米二氧化锡含量为40%时,纳米SnO_2/C复合材料的电化学性能最佳。在电流密度为100 m A/g充放电时,首次可逆比容量为825.2 m Ah/g,第100次循环的可逆比容量为593.2 m Ah/g,容量保持率达71.9%。展开更多
Carbon-supported Pt/C,Pt/Re/C,Pt/SnO2/C and Pt/Re/SnO2/C,with 20 wt.%overall metal loading were prepared and their electrochemical activity towards ethanol oxidation reaction(EOR)was investigated.Transmission electron...Carbon-supported Pt/C,Pt/Re/C,Pt/SnO2/C and Pt/Re/SnO2/C,with 20 wt.%overall metal loading were prepared and their electrochemical activity towards ethanol oxidation reaction(EOR)was investigated.Transmission electron microscopy(TEM)combined with energy dispersive X-ray spectroscopy(EDS)revealed,that indeed binary and ternary combinations of the designed nanoparticles(NPs)were formed and successfully uniformly deposited on a carbon support.Fourier transform infrared spectroscopy(FTIR)allowed to assess the chemical composition of the nanocatalysts and X-ray diffraction(XRD)allowed to determine the catalyst structure.Potentiodynamic and chronoamperometric measurements were used to establish its catalytic activity and stability.The influence of Re addition on the electrochemical activity towards ethanol oxidation reaction(EOR)was verified.Indeed,the addition of Re to the binary Pt/SnO2/C catalyst leads to the formation of ternary Pt/Re/SnO2/C with physical contact between the individual NPs,enhancing the EOR.Furthermore,the onset potential of the synthesized ternary catalyst is shifted to more negative potentials and the current densities and specific activity are nearly 11 and 5 times higher,respectively,than for commercial Pt catalyst.Additionally ternary Pt/Re/SnO2/C catalyst retained 96%of its electrochemical surface area.展开更多
PtSn2-SnO2/C nanocatalyst was prepared by co-reduction of Pt and Sn precursor at ca,15℃.The formation of PtSn2-SnO2 nanoparticle was determined by XRD,TEM and XPS characterization.This PtSn2-SnO2/C nanocatalyst exhib...PtSn2-SnO2/C nanocatalyst was prepared by co-reduction of Pt and Sn precursor at ca,15℃.The formation of PtSn2-SnO2 nanoparticle was determined by XRD,TEM and XPS characterization.This PtSn2-SnO2/C nanocatalyst exhibits stronger resistance to CO poisoning and effectively improves methanol electro-catalytic effect,up to 3 times than the commercial Pt/C catalyst.展开更多
文摘采用化学沉淀法,并通过进一步的水热反应,制备得到纳米二氧化锡颗粒,通过TEM分析知纳米二氧化锡颗粒的粒径约为5 nm;通过2,4-二羟基苯甲酸和甲醛之间的缩合反应,在体系中加入纳米二氧化锡颗粒,再通过水洗和热处理等步骤制备了纳米SnO_2/C碳包覆微球,控制加入二氧化锡纳米颗粒的质量制备了不同样品来探究其对材料形貌及性能的影响。研究表明,当添加纳米二氧化锡含量为40%时,纳米SnO_2/C复合材料的电化学性能最佳。在电流密度为100 m A/g充放电时,首次可逆比容量为825.2 m Ah/g,第100次循环的可逆比容量为593.2 m Ah/g,容量保持率达71.9%。
文摘Carbon-supported Pt/C,Pt/Re/C,Pt/SnO2/C and Pt/Re/SnO2/C,with 20 wt.%overall metal loading were prepared and their electrochemical activity towards ethanol oxidation reaction(EOR)was investigated.Transmission electron microscopy(TEM)combined with energy dispersive X-ray spectroscopy(EDS)revealed,that indeed binary and ternary combinations of the designed nanoparticles(NPs)were formed and successfully uniformly deposited on a carbon support.Fourier transform infrared spectroscopy(FTIR)allowed to assess the chemical composition of the nanocatalysts and X-ray diffraction(XRD)allowed to determine the catalyst structure.Potentiodynamic and chronoamperometric measurements were used to establish its catalytic activity and stability.The influence of Re addition on the electrochemical activity towards ethanol oxidation reaction(EOR)was verified.Indeed,the addition of Re to the binary Pt/SnO2/C catalyst leads to the formation of ternary Pt/Re/SnO2/C with physical contact between the individual NPs,enhancing the EOR.Furthermore,the onset potential of the synthesized ternary catalyst is shifted to more negative potentials and the current densities and specific activity are nearly 11 and 5 times higher,respectively,than for commercial Pt catalyst.Additionally ternary Pt/Re/SnO2/C catalyst retained 96%of its electrochemical surface area.
基金supported by NSFC (Nos. 21373116 and 21421001)the Tianjin Natural Science Research Fund (No. 13JCYBJC18300)+1 种基金RFDP (No. 20120031110005)the MOE Innovation Team (No. IRT13022) of China
文摘PtSn2-SnO2/C nanocatalyst was prepared by co-reduction of Pt and Sn precursor at ca,15℃.The formation of PtSn2-SnO2 nanoparticle was determined by XRD,TEM and XPS characterization.This PtSn2-SnO2/C nanocatalyst exhibits stronger resistance to CO poisoning and effectively improves methanol electro-catalytic effect,up to 3 times than the commercial Pt/C catalyst.
基金The project was supported by the National Natural Science Foundation of China(No.20871107)He'nan Outstanding Youth Science Fund(No.0612002700)the Natural Science Foundation of the Education of Henan province(No.2009A150031)
