A hierarchy of global coupling induced cluster patterns during the oscillatory H2-electrooxidation reaction on a Pt ring-electrode.
A hierarchy of global coupling induced cluster patterns during the oscillatory H2-electrooxidation reaction on a Pt ring-electrode.
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DOI：
10.1039/b502027a
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发表时间：
2005-06
期刊：
影响因子：
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通讯作者：
H. Varela;C. Beta;A. Bonnefont;K. Krischer
中科院分区：
文献类型：
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作者：
H. Varela;C. Beta;A. Bonnefont;K. Krischer
报道了负(去同步)全局耦合(GC)下铂环电极上振荡氢电氧化反应时空图样形成的实验结果。利用电势探头记录了沿环电极角方向的界面电势降的一维空间分布。研究了外加电压U和全局耦合强度两个控制参数对系统动力学的影响。后者可通过改变工作电极(WE)和参比电极(RE)之间的距离或通过插入与WE串联的负阻抗装置来调节。在没有全局耦合的情况下，迁移耦合破坏了均匀振荡的稳定性，并且在较大的U(H.Varela，C.Beta，A.Bonnefont和K.Krischer，Phys)值下发展了电化学湍流。雷特牧师，2005年，94,174104；)。已经很低的全球耦合强度足以抑制湍流。相反，形成了规则的两相星团。在较高的耦合强度下，观察到了第二类两相团簇和两种不规则的团簇图案，它们分别与团簇边界的不规则运动和通过边界的分裂和合并而出现和消失的团簇有关。当进一步增加耦合强度时，五相团簇稳定，在最高耦合强度时，团簇图案转变为强调制脉冲。利用多种信号处理技术，分析了两种类型的两相簇和五相簇。
We report experimental results on spatiotemporal pattern formation during the oscillatory hydrogen electrooxidation reaction on a Pt ring-electrode under negative (desynchronizing) global coupling (GC). Spatially one-dimensional profiles of the interfacial potential drop along the angular direction of the ring electrode are recorded by means of a potential probe. The dynamics is investigated as a function of two control parameters, the applied voltage U and the strength of the global coupling. The latter is adjusted either by varying the distance between the working electrode (WE) and the reference electrode (RE) or by inserting a negative impedance device in series with the WE. In the absence of global coupling, uniform oscillations were destabilized by migration coupling, and electrochemical turbulence developed at large values of U (H. Varela, C. Beta, A. Bonnefont and K. Krischer, Phys. Rev. Lett., 2005, 94, 174104; ). Already low global coupling strengths sufficed to suppress turbulence. Instead, regular two-phase clusters formed. At higher coupling strength, a second type of two-phase cluster was observed as well as two types of irregular cluster patterns, which were connected with an irregular motion of the cluster boundaries and the emergence and disappearance of clusters through splitting and merging of the boundaries, respectively. Upon increasing the coupling strength even further, five-phase clusters were stabilized and at the highest coupling strength applied the cluster patterns transformed into strongly modulated pulses. The two types of two-phase clusters and the five-phase clusters are analyzed employing several signal processing techniques.