Reactivity Descriptors for the Activity of Molecular MN4 Catalysts for the Oxygen Reduction Reaction.
Reactivity Descriptors for the Activity of Molecular MN4 Catalysts for the Oxygen Reduction Reaction.
复制标题
DOI：
10.1002/anie.201604311
复制
发表时间：
2016-11
影响因子：
--
通讯作者：
J. Zagal;M. Koper
中科院分区：
文献类型：
--
作者：
J. Zagal;M. Koper
在金属电极的公知反应性描述符之间建立了它们在氧还原反应（ORR）中的活性和分子催化剂的反应性的相似性，特别是限制于电极表面的大环MN 4金属络合物。我们发现，有一个相关性之间的MIII /MII的氧化还原电位MN 4螯合物和M-O2结合能。具体而言，O2（和其他O物质）的结合能遵循MnN 4和FeN 4螯合物的MIII-OH/MII氧化还原转变。MN 4催化剂的ORR火山图与金属催化剂相似：弱结合侧的催化剂（主要是CoN 4螯合物）主要产生H2 O2作为产物，ORR起始电位与NHE标度上的pH值无关（因此pH依赖于RHE标度）;强结合侧的催化剂产生H2 O作为产物，预期pH依赖于NHE标度。建议的描述符也适用于热处理的热解MN 4催化剂。
Similarities are established between well-known reactivity descriptors of metal electrodes for their activity in the oxygen reduction reaction (ORR) and the reactivity of molecular catalysts, in particular macrocyclic MN4 metal complexes confined to electrode surfaces. We show that there is a correlation between the MIII /MII redox potential of MN4 chelates and the M-O2 binding energies. Specifically, the binding energy of O2 (and other O species) follows the MIII -OH/MII redox transition for MnN4 and FeN4 chelates. The ORR volcano plot for MN4 catalysts is similar to that for metal catalysts: catalysts on the weak binding side (mostly CoN4 chelates) yield mainly H2 O2 as the product, with an ORR onset potential independent of the pH value on the NHE scale (and therefore pH-dependent on the RHE scale); catalysts on the stronger binding side yield H2 O as the product with the expected pH-dependence on the NHE scale. The suggested descriptors also apply to heat-treated pyrolyzed MN4 catalysts.