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1.
铂微粒修饰聚2,3—二甲氧基苯胺电极对甲醇的电催化作用   总被引:3,自引:0,他引:3  
将以铂微粒修饰玻碳电极为基体的聚2,5-二甲氧基苯胺膜形成修饰电极循环伏安实验表明,Pt/PDMA/GC电极对甲醇氧化比分散于破碳电极上的铂催化活性更大,讨论了PDMA膜厚度,铂微粒含量及甲醇浓度对催化活性的影响,这种电极在酸性甲醇溶液中有良好的稳定性。  相似文献   

2.
2:18磷钼杂多酸的过氧化氢传感器   总被引:3,自引:0,他引:3  
杜丹  王升富 《分析化学》2000,28(10):1318-1318
1引言 有关Dawson型磷钼杂多酸修饰电极的研究报道甚少,本文按文献方法合成Dawson型磷用杂多酸H6P2Mo18O62(简写为P2Mo18)。采用电化学方法制得 P2Mo18/GC膜修饰电极,研究其在 0.5mol/L H2SO4溶液中的电化学行为,发现P2 Mo18/GC膜修饰电极对酸性水溶液中的H2Q2有较灵敏的催化活性,因而在GC上研制了P2Mo18/GC的 H2O2传感器,初步探讨了电催化还原机理。2实验部分2.1仪器与试剂XJP-821(B)型新极谱仪(中国科学院长春应用化学研究所,…  相似文献   

3.
研究了聚色氨酸修饰玻碳电极(Poly-Try/GC)的制备,用循环伏安法探讨了膜的电化学性质。在pH=6.6的PBS中,膜的循环伏安图上有两对氧化还原峰。掺杂金属离子Ni(Ⅱ)后的该聚合物膜修饰电极(Poly-Ni(Ⅱ) Try/GC)对甲醇的催化活性大大提高,在0.01 mol/L NaOH中甲醇的氧化峰电位在0.65 V,而同样条件下在空白玻璃电极(GC)和Poly-Try/GC上甲醇的氧化峰电位要正得多。在0.15 mol/L甲醇溶液中循环伏安扫描150 min后,峰电流密度由1060 μA/cm~2降低至885μA/cm~2,然后峰电流密度不再降低,说明在电催化氧化甲醇过程中电极稳定性良好。  相似文献   

4.
甲醇在铂微粒修饰的聚硫堇电极上的电催化氧化   总被引:6,自引:0,他引:6  
利用电化学循环伏安和现场FTIR反射光谱等技术研究了甲醇在铂微粒修饰的聚硫堇电极上的电催化氧化。结果表明,循环伏安法制备的铂微粒均匀分散于聚合物膜上,其粒径大小约为30-130nm;复合修饰电极对甲醇电化学氧化呈现了较高的催化活性,其催化活性的大小依赖于Pt载量。现场FTIR光谱实验揭示了线性吸附的CO物种是甲醇在复合电极上氧化的唯一中间体,这种吸附的CO物种在复合修饰电极上更容易被氧化为最终产物  相似文献   

5.
载铂微粒的聚苯胺薄膜电极对甲醇的电催化氧化   总被引:9,自引:1,他引:9  
用电化学方法制备的载有金属铂微粒的聚苯胺(PAn)膜电极对甲醇在硫酸中的电化学氧化具有很高的催化活性。电极材料中的铂微粒是沿着聚苯胺的纤维分布的,而且主要沉积在PAn膜的表面。  相似文献   

6.
铂微粒修饰的聚苯胺薄膜电极对甲醛氧化的电催化作用   总被引:6,自引:2,他引:6  
以电位扫描法把铂微粒沉积在聚苯胺(PAn)薄膜是上以制得铂微粒修饰的聚苯胺薄膜电极。该电极的催化活性以甲醛在0.5mol/L硫酸溶液中的电化学氧化测定。它集催化活性和电活性于一体,对甲醛在酸性介质中的电化学氧化显示了非常高的电催化活性。较之裸铂电极,PAn薄膜电极,其催化电流提高10倍。铂微粒的大小,分布和载量,甲醛的浓度,基体金属的种类等因素对电极材料的催化活性均有影响。  相似文献   

7.
脱氧核糖核酸变性和损伤的吸附伏安法研究   总被引:2,自引:0,他引:2  
陆宗鹏  卢莠芬 《分析化学》1996,24(4):463-466
本文用汞电极(HMDE)二次导数阴极吸附伏安(SD-AdCSV)和碳电极(GCE、CPE)导数循环伏安(FD-CV)法研究了核酸受热、紫外线、超声波和丝裂霉素C(MMC)作用下的变性作用。在0.1mol/L(K2HPO4+KH2PO4)-0.1mol.L NaCl(pH7.0)底液中,吸附的单股(ss-)和双螺旋(ds-)DNA分别在HMDE上得到特征还原峰P3和P2,和在碳电极上得到氧化峰A。物  相似文献   

8.
研究了细胞色素C(Cyt.C)在一种新的电子转移促进剂4,6-二甲基-2-巯基嘧啶修饰微带金电极(DMMP/Au)上的氧化还原热力学;求得Cyt.C在DMMP/Au电极上反应的标准电极电位E^o,熵变△S^o,焓变△II^o及Gibbs自由能的改变△G10值分别为:0.272V(us.NHE),-123.7J.mol^-^1,-63.1kJ.mol.mol^-^1和-26.2kJ.mol^-^1(  相似文献   

9.
研究了电化学方法制备的铂微粒弥散的聚2,5-二甲氧基苯胺膜电极对甲醇电氧化的催化行为以及影响催化活性的主要因素。以XPS、SEM表征了这种电极材料的表面结构,结果表明,在酸性介质中,该膜电极对甲醇电氧化有高的催化活性和稳定性。  相似文献   

10.
研究了电化学方法制备的铂微粒弥散的聚2,5-二甲氧基苯胺膜电极对甲醇电氧化的摧化行为以及影响催化活性的主要因素,以XPS、SEM表征了这种电极材料的表面结构。结果表明,在酸性介质中,该膜电极对甲醇电氧化有高的催化活性和稳定性。  相似文献   

11.
A comparative investigation of electrocatalytic and adsorption properties of platinum microparticles electrodeposited onto a glassy carbon surface (Pt/GC) and within a thin Nafion® film formed on a GC electrode (Pt/Nf/GC) is described. As test reaction the methanol oxidation in sulfuric acid solutions is used. Dependences of the steady-state specific reaction rates upon potential and methanol concentration were established, as well as those of the platinum surface coverage with methanol chemisorption products upon concentration. It was shown that at higher platinum loadings (above 60 μg cm−2) the specific activities of Pt/GC and Pt/Nf/GC are nearly the same and close to that of smooth platinum. At such loadings the surface coverage of the platinum deposit surface with organic particles does not differ from that of smooth platinum. At very low platinum loadings in the polymeric matrix (10–30 μg cm−2) a considerable decrease in the adsorption of strongly chemisorbed methanol particles is observed. These deposits are characterized by a low specific activity, which may be caused by the decrease of the platinum particle’s size, leading to a decrease in the amount of weakly bound methanol particles participating in the limiting reaction step.  相似文献   

12.
水热氧化法制备γ-Mn2O3   总被引:5,自引:0,他引:5  
万本强 《应用化学》1999,16(2):60-64
研究了用电化学方法制备的铂微粒修饰的聚2,5二甲氧基苯胺电极对甲酸的电催化氧化,用SEM、XPS表征了这种电极材料的表面结构,结果表明,这种复合电极对甲酸在酸性介质中电化学氧化具有很高的催化活性,较之裸铂电极其催化电流提高100多倍.循环伏安法制备的铂微粒较均匀地分布在聚合物上,其粒径大约为300nm.研究了铂微粒载量、阴离子种类、反应温度和浓度等因素对电极催化活性的影响.  相似文献   

13.
《Electroanalysis》2006,18(9):911-917
Electrooxidation of methanol on glassy carbon (GC) electrode modified by optimum carbon supported Pt electrocatalyst (Pt‐C/GC) in acid media is investigated. The catalyst is prepared by ultrasonicating Pt/C powders in aqueous media. The activity of prepared Pt‐C/GC electrode is studied in potential range of 0–1000 mV (versus SCE) by cyclic voltammetry. The results showed that the Pt/C dispersed layer at the surface of glassy carbon electrode, behaves as an electrocatalyst for the oxidation of methanol in acid medium by optimum loading of Pt (0.2 mg cm?2). The electrochemical properties of prepared electrode are studied under various conditions. However the effect of various parameters in the catalytic enhancement of Pt/C, such as platinum loading, sulfuric acid concentration, different scan rates, different final potentials, and medium temperature are considered and examined.  相似文献   

14.
The catalytic behavior of stainless steel (SS) electrode modified by a thin film of polyaniline (PANI) containing platinum particles was studied for electrooxidation of methanol and compared with a platinated Pt/PANI electrode in acidic aqueous solution. Cyclic voltammetry (CV), chronoamperometry, CO stripping techniques were used to investigate electrochemical properties and electrocatalytic activity of SS/PANI/Pt and Pt/PANI/Pt electrodes. The morphology and particle size of Pt catalysts were characterized by Transmission Electron Microscopy (TEM) measurement. The effects of various parameters such as thickness of polymer film, medium temperature and stability of the modified electrodes on methanol oxidation were also investigated. The results indicated that the modified SS electrode exhibited a considerably high electrocatalytic activity on the methanol oxidation as well as the modified Pt electrode.  相似文献   

15.
Pt微粒修饰纳米纤维聚苯胺电极对甲醇氧化电催化   总被引:9,自引:0,他引:9  
以脉冲电流法制备的纳米纤维状聚苯胺(PANI)为Pt催化剂载体,用它制备了甲醇阳极氧化的催化电极Pt/(nano-fibular PANI).研究结果表明, Pt/(nano-fibular PANI)电极对甲醇氧化具有很好的电催化活性,并有协同催化作用.在相同的Pt载量条件下, Pt/(nano-fibular PANI)电极比Pt微粒修饰的颗粒状聚苯胺电极Pt/(granular PANI)具有更好的电催化活性.此外, Pt的电沉积修饰方法同样影响Pt/(nano-fibular PANI)电极对甲醇氧化的催化活性.脉冲电流法沉积Pt形成的复合电极较循环伏安法电沉积得到的Pt复合电极具有更优异的催化活性.  相似文献   

16.
The influence of the iridium oxide thin film on the electrocatalytic properties of platinum nanoparticles was investigated using the electro-oxidation of methanol and CO as a probe. The presence of the IrO(2) thin film leads to the homogeneous dispersion of Pt nanoparticles. For comparison, polycrystalline platinum and Pt nanoparticles dispersed on a Ti substrate in the absence of an IrO(2) layer (Ti/Pt) were also investigated in this study. Inverted and enhanced CO bipolar peaks were observed using an in situ electrochemical Fourier transform infrared technique during the methanol oxidation on the Pt nanoparticles dispersed on a Ti substrate. Electrochemical impedance studies showed that the charge transfer resistance was significantly lower for the Ti/IrO(2)/Pt electrode compared with that of the massive Pt and Ti/Pt nanoparticles. The presence of the IrO(2) thin film not only greatly increases the active surface area but also promotes CO oxidation at a much lower electrode potential, thus, significantly enhancing the electrocatalytic activity of Pt nanoparticles toward methanol electro-oxidation.  相似文献   

17.
采用多壁碳纳米管(MWNT)改性聚N,N-二甲基苯胺(PDMA)膜,制备了新型复合膜修饰玻碳电极,并用SEM、电化学方法对修饰电极进行表征。 结果表明,无论MWNT是以掺杂还是先滴涂MWNT再聚合DMA多层修饰方式,均会改变PDMA膜的形貌和电化学性能。 复合膜修饰电极比单一PDMA膜修饰电极大幅度提高了比表面积和电活化面积,同时使PDMA和MWNT更好地协同发挥其优良的电化学特性。 实验结果表明,层层修饰制备的聚N,N-二甲基苯胺/多壁碳纳米管复合膜修饰电极对香草醛的电化学响应远大于基体电极和其它方法制备的修饰电极,电催化作用显著提高,其过电位降低了148 mV,氧化峰电流约增加了6倍;其电极反应是吸附控制的不可逆氧化过程,转移电子数n为2,质子数m为1,传递系数α为0.4062,吸附量为Γ=3.527×10-9 mol/cm2;检出下限为8.0×10-7 mol/L,样品平均回收率为99.87%。  相似文献   

18.
《Electroanalysis》2003,15(4):278-286
The electrocatalytic oxidation of methanol at a glassy carbon electrode modified by a thin film of poly(o‐aminophenol) (PoAP) containing Pt, Pt‐Ru and Pt‐Sn microparticles has been investigated using cyclic voltammetry as analytical technique and 0.10 M perchloric acid as supporting electrolyte. It has been shown that the presence of PoAP film increases considerably the efficiency of deposited Pt microparticles toward the oxidation of methanol. The catalytic activity of Pt particles is further enhanced when Ru or specially Sn is co‐deposited in the polymer film. The effects of various parameters such as the thickness of polymer film, concentration of methanol, medium temperature as well as the long term stability of modified electrodes have also been investigated.  相似文献   

19.
Effect of electrochemical oxidation of glassy carbon on deposition of platinum particles and electrocatalytic activity of platinum supported on oxidized glassy carbon (Pt/GCOX) were studied for methanol oxidation in H2SO4 solution. Platinum was potentiostatically deposited from H2SO4 + H2PtCl6 solution. Glassy carbon was anodically polarised in 0.5 M H2SO4 at 2.25 V vs. saturated calomel electrode (SCE) during 35 s. Electrochemical treatment of GC support, affecting not significantly the real Pt surface area, leads to a better distribution of platinum on the substrate and has remarkable effect on the activity. The activity of the Pt/GCOX electrode for methanol oxidation is larger than polycrystalline Pt and for more than one order of magnitude larger than Pt/GC electrode. This increase in activity indicates the pronounced role of organic residues of GC support on the properties of Pt particles deposited on glassy carbon.  相似文献   

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