The Influence of pH and Electrolyte Concentration on Fractional Protonation and CO 2 Reduction Activity in Polymer-Encapsulated Cobalt Phthalocyanine
The Influence of pH and Electrolyte Concentration on Fractional Protonation and CO 2 Reduction Activity in Polymer-Encapsulated Cobalt Phthalocyanine
复制标题
pH和电解质浓度对聚合物包封钴酞菁中部分质子化和CO 2 还原活性的影响
DOI：
10.1021/acs.jpcc.3c01490
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
McCrory, Charles C.
中科院分区：
文献类型：
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作者：
Soucy, Taylor L.;Dean, William S.;Rivera Cruz, Kevin E.;Eisenberg, Jonah B.;Shi, Lirong;McCrory, Charles C.
聚合物包覆酞菁钴（CoPc）是研究电催化体系中聚合物-催化剂相互作用如何影响CO2还原反应性能的模型体系。特别是，了解本体电解质和质子浓度如何影响聚合物质子化，以及聚合物质子化的程度如何影响催化活性和选择性，对于了解聚合物-催化剂复合材料至关重要。我们报告了一项研究的依赖性的散装pH值和电解质浓度的分数质子化的聚（4-乙烯基吡啶）和相关的聚合物与电化学和光谱的证据。此外，我们表明，分数质子化的聚合物是直接相关的催化剂的活性和反应选择性的CO2还原反应的竞争性析氢反应。特别值得注意的是，膜的部分质子化与电解质浓度有关，这表明反离子的传输在调节聚合物膜内的质子传输中起着重要作用。这些见解表明，电解质浓度和pH值的聚合物-催化剂复合系统的电催化性能中起着重要的作用，这些影响应考虑在实验制备和分析。
Polymer-encapsulated cobalt phthalocyanine (CoPc) is a model system for studying how polymer–catalyst interactions in electrocatalytic systems influence performance for the CO2reduction reaction. In particular, understanding how bulk electrolyte and proton concentration influence polymer protonation and in turn how the extent of polymer protonation influences catalytic activity and selectivity is crucial to understanding polymer–catalyst composite materials. We report a study of the dependence of bulk pH and electrolyte concentration on the fractional protonation of poly(4-vinylpyridine) and related polymers with both electrochemical and spectroscopic evidence. In addition, we show that the fractional protonation of the polymer is directly related to both the activity of the catalyst and the reaction selectivity for the CO2reduction reaction over the competitive hydrogen evolution reaction. Of particular note is that the fractional protonation of the film is related to electrolyte concentration, which suggests that the transport of counterions plays an important role in regulating proton transport within the polymer film. These insights suggest that electrolyte concentration and pH play an important role in the electrocatalytic performance for polymer–catalyst composite systems, and these influences should be considered in both experimental preparation and analysis.