Understanding the Impact of Peripheral Substitution on the Activity of Co Phthalocyanine in Sulfur Reduction Catalysis
Understanding the Impact of Peripheral Substitution on the Activity of Co Phthalocyanine in Sulfur Reduction Catalysis
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DOI：
10.1002/adfm.202313107
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发表时间：
2023-12
影响因子：
19
通讯作者：
Xinhong Zhao;Yukun Zhang;Weizhe Liu;Zhiqiang Zheng;Zhanghua Fu;Chuanzhong Chen;Cheng Hu
中科院分区：
文献类型：
--
作者：
Xinhong Zhao;Yukun Zhang;Weizhe Liu;Zhiqiang Zheng;Zhanghua Fu;Chuanzhong Chen;Cheng Hu
催化材料在促进锂硫电池中的硫利用方面是有效的。酞菁钴（CoPc）具有独特的平面单分子结构，具有高活性的Co-N4中心，用于硫还原催化。酞菁化合物的高度灵活性为电子结构调节提供了丰富的机会，以提高催化活性。为了指导未来的设计和筛选，本研究旨在通过检查两个典型的取代基：吸电子硝基和供电子氨基，了解外围取代的影响，这是获得CoPc衍生物的最常见方法。四硝基酞菁钴（CoTnPc）比四氨基酞菁钴（CoTaPc）在促进液-固转变过程中表现出显著更高的活性。取代通过影响静电势和Li─键改变了Li 2S 4的稳定结合几何构型，使得Co─S键与CoTnPc上的桥连S原子在能量上有利。CoTnPc还使得从S 3 pz轨道到单独占据的Co 3 dz 2 ${d}_{{z}^2}$轨道的电子捐赠更大，显著削弱了桥接S─S键，从而增强了Li 2S 4随后的液固转变的反应性。理论计算的框架进行了测试，提供相关材料的筛选描述符。通过在高硫负载和有限的电解质添加下具有CoTnPc的袋式电池证明了CoPc衍生物的潜力。
Catalytic materials are effective in promoting sulfur utilization in lithium‐sulfur batteries. Co phthalocyanine (CoPc) presents a unique planner single‐molecular structure with a highly active Co‐N4 center for sulfur reduction catalysis. The high flexibility of phthalocyanines offers rich opportunities for electronic structure modulation toward enhanced catalytic activities. To guide future design and screening, this study aims to understand the impact of peripheral substitution, the most common method to obtain CoPc derivatives, by examining two typical substituents: the electron‐withdrawing nitro and electron‐donating amino groups. Co tetranitrophthalocyanine (CoTnPc) presents a significantly higher activity in promoting the liquid‐solid transition process than Co tetraaminophthalocyanine (CoTaPc). Substitution alters the stable binding geometry of Li2S4 by influencing the electrostatic potential and Li─bond, making the Co─S bond energetically favorable with the bridging S atoms on CoTnPc. CoTnPc also enables a greater electron donation from the S 3pz orbital to the singly occupied Co 3 dz2${d}_{{z}^2}$ orbital, significantly weakening the bridging S─S bond to enhance the reactivity of Li2S4 for the subsequent liquid‐solid transition. A framework of theoretical calculation is tested, providing descriptors for the screening of related materials. The potential of CoPc derivatives is demonstrated by pouch cells with CoTnPc under high sulfur loading and limited electrolyte addition.