Natural Assembly of Electroactive Metallopolymers on the Electrode Surface: Enhanced Electrocatalytic Production of Hydrogen by [2Fe–2S] Metallopolymers in Neutral Water
Natural Assembly of Electroactive Metallopolymers on the Electrode Surface: Enhanced Electrocatalytic Production of Hydrogen by [2Fe–2S] Metallopolymers in Neutral Water
复制标题
电极表面电活性金属聚合物的自然组装：[2Fe-2S]金属聚合物在中性水中增强电催化产氢
DOI：
10.1021/jacs.3c03379
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发表时间：
2023
影响因子：
15
通讯作者：
Lichtenberger, Dennis L.
中科院分区：
文献类型：
--
作者：
Clary, Kayla E.;Gibson, Arthur C.;Glass, Richard S.;Pyun, Jeffrey;Lichtenberger, Dennis L.
附着在电极表面的分子催化剂可以提供均相和非均相催化的优点。不幸的是，一些限制在表面上的分子催化剂失去了大部分或全部的溶液性能。相比之下，我们发现，当将小分子[2Fe-2S]催化剂掺入PDMAEMA-g-[2Fe-2S]（PDMAEMA =聚（2-二甲氨基）甲基丙烯酸乙酯）形式的金属聚合物中并吸附到表面时，观察到的产氢速率增加到每个活性位点> 105s-1，具有较低的过电势、增加的寿命和对氧气的耐受性。在此，比较了这些具有不同长度聚合物链的金属聚合物的电催化性能，以揭示导致这种高性能的因素。预计较小的金属聚合物将具有更快的速率，因为电子和质子转移到更容易接近的活性位点的速度更快，但实验表明每个活性位点的催化速率与聚合物尺寸无关。分子动力学模型表明，高性能是这些金属聚合物通过自然组装吸附在表面上的结果，使[2Fe-2S]催化位点与电极表面紧密接触，同时保持这些位点暴露于溶液中的质子。无论聚合物尺寸如何，该组装都有利于快速电子转移、快速质子转移和高催化速率。这些结果为通过掺入聚合物中来增强其他电催化剂的性能提供了指导，从而提供了催化剂与电极和溶液的最佳相互作用。
A molecular catalyst attached to an electrode surface can offer the advantages of both homogeneous and heterogeneous catalysis. Unfortunately, some molecular catalysts constrained to a surface lose much or all of their solution performance. In contrast, we found that when a small molecule [2Fe–2S] catalyst is incorporated into metallopolymers of the form PDMAEMA-g-[2Fe–2S] (PDMAEMA = poly(2-dimethylamino)ethyl methacrylate) and adsorbed to the surface, the observed rate of hydrogen production increases tokobs> 105s–1per active site with lower overpotential, increased lifetime, and tolerance to oxygen. Herein, the electrocatalytic performances of these metallopolymers with different length polymer chains are compared to reveal the factors that lead to this high performance. It was anticipated that smaller metallopolymers would have faster rates due to faster electron and proton transfers to more accessible active sites, but the experiments show that the rates of catalysis per active site are independent of the polymer size. Molecular dynamics modeling reveals that the high performance is a consequence of adsorption of these metallopolymers on the surface with natural assembly that brings the [2Fe–2S] catalytic sites into close contact with the electrode surface while maintaining exposure of the sites to protons in solution. The assembly is conducive to fast electron transfer, fast proton transfer, and a high rate of catalysis regardless of the polymer size. These results offer a guide to enhancing the performance of other electrocatalysts with incorporation into a polymer that provides an optimal interaction of the catalyst with the electrode and solution.