The electrochemical and in-situ surface-enhanced Raman spectroscopy （SERS） techniques were used to investigate the electrooxidation behavior of methanol in acidic, neutral and alkaline media at a Pt-Ru nanoparticle ...The electrochemical and in-situ surface-enhanced Raman spectroscopy （SERS） techniques were used to investigate the electrooxidation behavior of methanol in acidic, neutral and alkaline media at a Pt-Ru nanoparticle modified glassy carbon （Pt-Ru/GC） electrode. The results showed that methanol could be dissociated spontaneously at the Pt-Ru/GC electrode to produce a strongly adsorbed intermediate, CO. It was found that CO could be oxidized more easily in the alkaline medium than in the acidic and neutral media. The peak potential of methanol oxidation was shifted from 0.663 and 0.708 V in the acidic and neutral media to -0.030 V in the alkaline medium, which is due to that the adsorption strength of CO on the Pt surface in the alkaline medium is weaker than that in the acidic and neutral media. The final product of the methanol oxidation is CO2. However, in the alkaline medium, CO2 produced would form CO3^2- and HCO3^- resulting in the decrease in the alkaline concentration and then in the decrease in the performance of DMFC. Therefore, the performance of the alkaline DMFC is not Stable.展开更多
文摘以硒球为模板合成了金纳米空球及其修饰玻碳电极，采用 SEM、XRD 和电化学循还伏安（CV）法，对金纳米空球的表面形貌和晶体结构进行了表征.实验结果表明：其粒径约为150 nm，壳厚约为25 nm，球壳表面由荔枝状的金原子簇团所构建，为多晶面心立方结构；应用电化学原位表面增强拉曼光谱技术，以吡啶为探针分子，初步研究了金纳米空球的 SERS 活性，计算其增强因子约为7.6x10^4；通过电化学和电化学原位表面增强拉曼光谱技术考察了硫氰根离子在金纳米空球上的吸附与氧化行为，发现在-0.80-0.60 V 的电位区间，SCN -离子通过电位调制可分别以 S 和 N 端竞争吸附在金纳米空球表面，但在0.60 V时，SCN -就开始氧化成 OCN -离子，当电极电位≥0.70 V 时，主要检测到位于2223 cm -1处OCN -离子在双电层的溶液谱.研究结果可为谱学电化学、电分析生物检测和靶向药物制备与检测等领域带来某些应用.
文摘The electrochemical and in-situ surface-enhanced Raman spectroscopy （SERS） techniques were used to investigate the electrooxidation behavior of methanol in acidic, neutral and alkaline media at a Pt-Ru nanoparticle modified glassy carbon （Pt-Ru/GC） electrode. The results showed that methanol could be dissociated spontaneously at the Pt-Ru/GC electrode to produce a strongly adsorbed intermediate, CO. It was found that CO could be oxidized more easily in the alkaline medium than in the acidic and neutral media. The peak potential of methanol oxidation was shifted from 0.663 and 0.708 V in the acidic and neutral media to -0.030 V in the alkaline medium, which is due to that the adsorption strength of CO on the Pt surface in the alkaline medium is weaker than that in the acidic and neutral media. The final product of the methanol oxidation is CO2. However, in the alkaline medium, CO2 produced would form CO3^2- and HCO3^- resulting in the decrease in the alkaline concentration and then in the decrease in the performance of DMFC. Therefore, the performance of the alkaline DMFC is not Stable.
