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1.
Pt及其修饰电极对丙三醇氧化的电催化性能研究   总被引:2,自引:0,他引:2  
运用电化学循环伏安和石英晶体微天平研究了丙三醇在Pt电极和以Sb,S吸附原子修饰的Pt(Pt/Sbad和Pt/Ssd)电极上的吸附和氧化过程。结果表明丙三醇的氧化与电极表面氧物种有着极其密切的关系。Pt电极表面Sb吸附原子能在较低的电位下吸附氧,可显著提高丙三醇电催化氧化活性,与Pt电极相比较,Sb吸附原子修饰的Pt电极使丙三醇氧化的峰电位负移了0.14V,相反,Pt电极表面S吸附原子的氧化合消耗表面氧物种,几乎完全抑制了丙三醇的电氧化。本文还从表面质量变化提供了吸附原子电催化作用的新数据。  相似文献   

2.
用SNIFTIRS方法研究了苯甲酸钠在铂电极上发生KOBLE反应前的吸附行为.实验结果表明,负电势增加,苯甲酸钠分子垂直吸附在电极表面的量增加;正电势增加,苯甲酸钠分子平躺吸附在电极表面的量增加.苯甲酸分子吸附取向的改变导致了电极表面水分子吸附取向发生与其相同的变化,并发现在电极表面附近存在苯甲酸与苯甲酸钠的平衡.  相似文献   

3.
应用电化学循环伏安和原位电化学石英晶体微天平(EQCM)方法研究了0.1mol.L^-1硫酸溶液中β—丙氨酸在Pt电极上的吸附和氧化过程。结果表明:0.1mol.L^-1硫酸溶液中氢脱附电位区间内电极表面质量的增加是由于水分子取代Had引起的,而双电层区的质量增加是由于水的吸附模式逐渐由氢端吸附转向氧端吸附所致,根据频率变化和电量数据,可进一步推算出酸性溶液中β—丙氨酸在Pt电极表面只发生弱吸附,水和β—丙氨酸阴离子都可以取代部分氢,吸附在电极表面,影响了电极表面质量的变化量,而吸附态β—丙氨酸在高电位氧化时会消耗Pt表面的氧。本文结果为认识β—丙氨酸在Pt电极表面过程提供定量的新数据。  相似文献   

4.
在饱和草酸溶液中运用双阶跃计时库仑技术研究草酸电解过程中电极表面吸附过程,以此探讨电极失活问题。研究发现在新鲜铅电极表面表现为产物乙醛酸(R)的吸附,但随着恒电流电解的进行电极表面逐渐地表现为反应物(O)的吸附。反应物的直接吸附不利于电荷转移,电极表面呈现钝化现象,电解电流效率也相应下降.  相似文献   

5.
研究了0.1 mol L -1 H2SO4中乙二醇在Pt电极和以吸附原子修饰的Pt (Pt/Sbad和Pt/Sad)电极上的吸附和氧化过程. 结果表明, 乙二醇的氧化与电极表面氧物种有着极其密切的关系. Pt电极表面Sb吸附原子能在较低的电位下吸附氧,可显著提高乙二醇电催化氧化活性. 与Pt电极相比较, Sb吸附原子修饰的Pt电极使乙二醇氧化峰电位负移了0.20 V, 峰电流增加了近3 倍. 相反,Pt电极表面S吸附原子的氧化会消耗表面氧物种,几乎完全抑制了乙二醇的电氧化.  相似文献   

6.
运用电化学循环伏安和石英晶体微天平研究了1.3-丁二醇(1.3-BDL)-丁二醇(1.3-BDL)在Pt和以Sb原子修饰的Pt/Sbad电极上的吸附和氧化过程,结果表明1.3-丁二醇的氧化与电极表面氧物种有着极其密切的关系。Pt电极表面吸附Sb原子后能在较低的电位下吸附氧,可显著提高1.3-丁二醇电催化氧化活性,与Pt电极相比较,1.3-丁二醇在Pt/Sbad电极上氧化的峰电位负移了0.25V,峰电流增加了近1倍。本文从表面质量变化提供了吸附原子电催化作用的新数据。  相似文献   

7.
对不饱和有机酸在铱-铑合金电极上吸附和电化学还原过程的动力学规律和反应机理进行了系统的研究,在理论上揭示了电极材料的催化活性,以及发生在电极表面的吸附和电化学还原过程的动力学基本规律,确定了其反应机理。  相似文献   

8.
利用电化学石英微天平(EQCM),研究了表面活性剂在金电极上的吸附及其对金电极氧化还原过程的影响⒚结果表明:不同的表面活性剂在金电极上吸附能力不同,对金的氧化还原过程产生不同的影响⒚十八烷基三甲基溴化铵易在金电极表面吸附,更易在氧化态金表面吸附,阻碍了金的氧化还原⒚相比之下,十二烷基磺酸钠在金电极上吸附能力较弱,在氧化态金形成后还有些脱落,对金电极的氧化还原影响不大⒚TritonX100介于以上两种表面活性剂之间⒚还对金电极在磷酸缓冲液中的氧化还原机理作了初步探讨  相似文献   

9.
本文运用共聚焦显微拉曼仪结合特殊的电极表面粗糙方法首次获得了Fe(CN)6^3/4-在铂电极表面氧化还原过程的拉曼光谱图。研究结果表明Fe(CN)6^3-在电极表面的吸附能力比Fe(CN)^4-强,它们都是通过CN上的N原子和电极表面成键而发生化学吸附的。  相似文献   

10.
对不饱和有机酸在铱-铑合金电极上的吸附和电化学还原过程的动力学规律和反应机理进行了系统的研究.在理论上揭示了电极材料的催化活性,以及发生在电极表面的吸附和电化学还原过程的动力学基本规律.确定了其反应机理.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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