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首页> 外文期刊>Electrocatalysis >Volcano Plots and Effective Reversible Potentials for Oxygen Electroreduction
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Volcano Plots and Effective Reversible Potentials for Oxygen Electroreduction

机译：氧电还原的火山图和有效可逆势

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It has recently been found that there are ideal values for O, OH, and OOH Gibbs adsorption bond strengths to a catalyst that will allow each electron transfer step to have 1.23 V for its reversible potential. In the case of Pt(111), the bond strengths are too high by ～0.9 eV for O and ～0.7 eV for OH and too small by -0.4 eV for OOH. These discrepancies result in OOH(ads) dissociation to O (ads)+OH(ads) being ～1.2 eV exergonic. The lost Gibbs energy causes the reversible potential for the four-electron reduction on Pt(111) to have a value of ～0.9 V, which is called the effective reversible potential. Volcano plots of activity measured at around 0.9 V depend on the adsorption energies scaling, that is, if one increases they all increase, or if one decreases they all decrease. Volcano plots have been drawn for several transition metal catalysts and platinum and platinum alloy catalysts in the pioneering work of Appleby, Mukerjee, and Adzic and have been seen by many other workers. Although they allow grading the active catalysts in the high overpotential region where reduction current flows, they do not point the direction to better catalysts that will operate at potentials approaching 1.23 V. The search should be for new catalysts which with the right balance of OOH, O, and OH adsorption energies.
机译：最近发现，对于催化剂，O，OH和OOH Gibbs的吸附键强度存在理想值，这将使每个电子转移步骤的可逆电位均具有1.23V。在Pt（111）的情况下，O的结合强度太高了约0.9 eV，OH的结合强度太了约0.7 eV，而OOH的结合强度太小了-0.4 eV。这些差异导致OOH（ads）解离为O（ads）+ OH（ads）约1.2 eV。损失的吉布斯能量使Pt（111）上的四电子还原的可逆电位的值约为0.9 V，称为有效可逆电位。在0.9 V左右测得的火山活动图取决于吸附能的大小，也就是说，如果一个增加，则它们全部增加，或者如果一个减少，则它们全部减小。在Appleby，Mukerjee和Adzic的开创性工作中，已经绘制了几种过渡金属催化剂以及铂和铂合金催化剂的火山图，并被许多其他工作者发现。尽管它们允许在还原电流流过的高超电势区域中对活性催化剂进行分级，但它们并没有指明向更好的催化剂运行的方向，这些更好的催化剂将在接近1.23 V的电势下运行。应寻找具有适当平衡的OOH， O和OH的吸附能。

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