preparationandcharacterizationofmethanoltolerantpdcocelectrocatalystsfordirectmethanolfuelcells

Pd/C and Pd-Co/C electrocatalysts were prepared by sodium borohydride co-reduction and successive reduction. X-ray diffraction, transmission electron microscopy, cyclic voltammetry, and rotating disk electrode were carried out to characterize these electrocatalysts. The results showed that the Pd-Co/C electrocatalysts have a single-phase face-centered-cubic disordered structure and the lattice constant is obviously smaller than that of Pd/C electrocatalyst. The Pd-Co/C electrocatalyst prepared by the successive reduction method not only has the highest oxygen reduction reaction activity but also shows good methanol tolerant capability

一种用于质子交换膜燃料电池的电催化剂

一种用于质子交换膜燃料电池的电催化剂，活性组分为Pt或PtRu，助剂组分为钛氧化物；铂与钛的原子比为0.01-99，铂与钌的原子比为 0.01-99，活性组分颗粒的粒径为1-20nm。该活性组分可以担载在经钛氧化物修饰的多孔导电材料上，得到担载型电催化剂，其中活性组分担载量的质量百分数为1-99％，铂与钛的原子比为0.01-99。活性组分中可以添加有质量百分数为0-99％的辅助组分，形成多组元的催化剂；添加的辅助组分为过渡金属或过渡金属氧化物的一种或几种。制备方法可以采用胶体法或浸渍-还原法。本发明的电催化剂可以应用在质子交换膜燃料电池中。带填

In situ Electrochemical FTIR Spectroscopy of Adsorption and Oxidation Process of Methanol on PtRu/C Electrocatalyst

采用调变的多元醇法制备了高分散的Pt/C,PtRu/C和Ru/C电催化剂.XRD计算结果表明,PtRu/C电催化剂的平均粒径和合金度分别为2.2 nm和71%.采用电化学方法和原位傅里叶变换红外反射光谱方法(in situFTIRS)研究了甲醇在3种电催化剂上的吸附氧化过程,发现PtRu/C对甲醇的催化活性明显高于Pt/C,Ru的加入一方面影响了甲醇在Pt上的解离吸附性能,另一方面提供了Ru-OH物种,从而抑制了低电位下电催化剂中毒.红外光谱研究结果表明,线性吸附态CO(COL)是主要毒化物种,反应产物主要是CO2,还有少量的甲酸甲酯.根据实验结果讨论了甲醇在PtRu/C电催化剂上的氧化机理.A modified polyol process was used to prepare Pt/C,PtRu/C and Ru/C electrocatalysts.Calcula-ted from XRD patterns,the mean particle size of PtRu/C electrocatalyst was 2.2 nm and the percentage of Ru alloyed was 71%,respectively.Adsorption and electro-oxidation progress of methanol on PtRu/C electrocatalyst was investigated by in situ FTIRS,combined with electrochemical experiments.It is revealed that the activity of PtRu/C electrocatalyst for methanol oxidation was much higher than that of Pt/C.Addition of Ru in PtRu/C electrocatalyst changed the characteristic of methanol adsorption,and Ru-OH species could oxidize linear bonded CO(CO_L) at a lower potential,thus inhibited the catalyst poisoning.In addition,from FTIRs results,CO_L was evidently identified to the main poisonous species and the major product was CO_2.Methyl formate was also identified.Based on these results,the mechanism of methanol oxidation was discussed.厦门大学固体表面物理化学国家重点实验室开放课题(批准号:200304)资

Signori, regimi signorili e statuti nel Tardo Medioevo, Atti del VII Convegno del Comitato Italiano per gli Studi e le Edizioni delle Fonti Normative, Ferrara 5-7 ottobre 2000

Rassegna e confronto delle varie promulgazioni statutarie avutesi in Italia sotto regimi signoril

PtRu/C电催化剂上甲醇吸附氧化过程的电化学原位红外光谱

采用调变的多元醇法制备了高分散的Pt/C, PtRu/C和Ru/C电催化剂. XRD计算结果表明, PtRu/C电催化剂的平均粒径和合金度分别为2.2 nm和71%. 采用电化学方法和原位傅里叶变换红外反射光谱方法(in situ FTIRS)研究了甲醇在3种电催化剂上的吸附氧化过程, 发现PtRu/C对甲醇的催化活性明显高于Pt/C, Ru的加入一方面影响了甲醇在Pt上的解离吸附性能, 另一方面提供了Ru-OH物种, 从而抑制了低电位下电催化剂中毒. 红外光谱研究结果表明, 线性吸附态CO(CO_L)是主要毒化物种, 反应产物主要是CO_2, 还有少量的甲酸甲酯. 根据实验结果讨论了甲醇在PtRu/C电催化剂上的氧化机理

In situ electrochemical FTIR spectroscopy of adsorption and oxidation process of methanol on PtRu/C electrocatalyst

A modified polyol process was used to prepare Pt/C, PtRu/C and Ru/C electrocatalysts. Calculated from XRD patterns, the mean particle size of PtRu/C electrocatalyst was 2.2 nm and the percentage of Ru allayed was 71%, respectively. Adsorption and electro-oxidation progress of methanol on PtRu/C electrocatalyst was investigated by in situ FTIRS, combined with electrochemical experiments. It is revealed that the activity of PtRu/C electrocatalyst for methanol oxidation was much higher than that of Pt/C. Addition of Ru in PtR.u/C electrocatalyst changed the characteristic of methanol adsorption, and Ru-OH species could oxidize linear bonded CO (COL) at a lower potential, thus inhibited the catalyst poisoning. In addition, from FTIRs results, COL was evidently identified to the main poisonous species and the major product was CO2. Methyl formate was also identified. Based on these results, the mechanism of methanol oxidation was discussed