Theoretical Design of Molecular Electrocatalysts with Flexible Pendant Amines for Hydrogen Production and Oxidation
Theoretical Design of Molecular Electrocatalysts with Flexible Pendant Amines for Hydrogen Production and Oxidation
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DOI：
10.1021/jz3020277
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发表时间：
2013-02-07
影响因子：
5.7
通讯作者：
Hammes-Schiffer, Sharon
中科院分区：
文献类型：
--
作者：
Fernandez, Laura E.;Horvath, Samantha;Hammes-Schiffer, Sharon
氢氧化电催化剂的设计和生产对可再生替代能源的开发具有重要意义。总体目标是最大化周转频率并最小化过电位。我们使用计算方法来研究各种镍基分子电催化剂的垂胺。我们的研究重点是质子耦合电子转移（PCET）过程，包括络合物和电极之间的电子转移以及垂胺的镍中心和氮之间的分子内质子转移。更小的平衡Ni-N距离和更灵活的悬垂胺配体有利于协调PCET机制，这往往需要更低的过电位，从而减少了氮接近镍中心进行质子转移的能量惩罚。我们的计算为设计包含这些性质的催化剂提供了预测。这些设计原则将有助于开发下一代氢催化剂。
The design of hydrogen oxidation and production electrocatalysts is important for the development of alternative renewable energy sources. The overall objective is to maximize the turnover frequency and minimize the overpotential. We use computational methods to examine a variety of nickel-based molecular electrocatalysts with pendant amines. Our studies focus on the proton-coupled electron transfer (PCET) process involving electron transfer between the complex and the electrode and intramolecular proton transfer between the nickel center and the nitrogen of the pendant amine. The concerted PCET mechanism, which tends to require a lower overpotential, is favored by a smaller equilibrium Ni-N distance and a more flexible pendant amine ligand, thereby decreasing the energetic penalty for the nitrogen to approach the nickel center for proton transfer. Our calculations provide predictions about designing catalysts that incorporate these properties. These design principles will be useful for developing the next generation of hydrogen catalysts.