Localised visualisation of O2 consumption and H2O2 formation by means of SECM for the characterisation of fuel cell catalyst activity
Localised visualisation of O2 consumption and H2O2 formation by means of SECM for the characterisation of fuel cell catalyst activity
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DOI：
10.1016/j.electacta.2007.02.028
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发表时间：
2007-12-20
影响因子：
6.6
通讯作者：
Schuhmann, Wolfgang
中科院分区：
文献类型：
--
作者：
Eckhard, Kathrin;Schuhmann, Wolfgang
O-2在金属催化剂上的催化还原要么遵循2电子转移途径形成H2 O2，要么遵循4电子转移途径形成H2O。该反应的支化比对催化剂材料的适用性具有显著影响。先前引入的氧竞争模式的SECM，它允许高分辨率成像的局部O-2消耗，已被扩展到一个潜在的脉冲序列，使顺序检测O-2还原，然后检测局部H2 O2的形成。因此，不仅可以可视化催化剂的局部催化活性，而且还可以估计支化度。因此，催化剂候选物的选择性可以顺序地可视化以阐明其活性。电沉积的Pt和一个测试结构的性能上的第一个结果示出证明的可行性，以清楚地区分催化剂的活性和选择性下的极化电位的变化。(c)2007爱思唯尔有限公司版权所有。
Catalytic reduction of O-2 at metal catalysts either follows a 2-electron transfer pathway to the formation of H2O2 or a 4-electron transfer pathway to the formation of H2O. The branching ratio of this reaction has a significant impact on the applicability of catalyst materials. The previously introduced oxygen competition mode of SECM, which allows high-resolution imaging of local O-2 consumption, has been extended to a potential-pulse sequence enabling the sequential detection of O-2 reduction followed by the detection of local H2O2 formation. Thus, not only the local catalytic activity of a catalyst can be visualised but, additionally, the degree of the branching can be estimated. The selectivity of a catalyst candidate can thereby be visualised sequentially to the elucidation of its activity. First results on the properties of electrodeposited Pt and An test structures are shown demonstrating the feasibility to clearly distinguish catalyst activity and selectivity under variation of the polarisation potential. (c) 2007 Elsevier Ltd. All rights reserved.