河南大学陈珂团队报道了促进硫还原电催化的共催化单原子支持相互作用。相关研究成果发表在2025年2月6日出版的《德国应用化学》。

使用具有丰富电催化中心的单原子催化剂（SACs）已被确定为抑制锂硫电池中穿梭效应的最理想策略。然而，SAC与其支撑物通过相互作用的共同贡献对加速硫还原反应（SRR）的支持迄今为止很少受到关注，因为其潜在机制仍然难以捉摸。

该文中，在密度泛函理论计算的指导下，选择石墨氮化碳基底（Co-GCN）上的钴-SACs来阐明其在增强SRR中的共催化作用。GCN固有的高电荷极性，结合其独特的三-s-三嗪结构，通过Li-N键为多硫化锂（LiPSs）提供了多个结合位点，并为锚定Co-SACs提供了N/C配位框架。这种结构配置进一步增强了通过Co-S键与LiPSs的相互作用。

因此，Co-SACs和GCN都通过结合LiPSs中间体积极参与硫还原电催化，降低了SRR的转化能垒。受益于这种独特的协同作用，该电池表现出优异的倍率性能（在5.0℃下为718.9 mAh g^-1），在8.7 mg cm^-2的高面积硫负载下，在5.0μL mg^-1的低电解质/硫比下，产生高达13.8 mAh cm^-2（1584.3 mAh g^-2）的高面积容量。

附：英文原文

Title: Insights into Co-Catalytic Single-Atom-Support Interactions for Boosting Sulfur Reduction Electrocatalysis

Author: Tianqi You, Huiyue Sun, Wuxing Hua, Shuang Geng, Zhonghao Hu, Yongqi Shang, Qunzhi Huang, Shuxi Dai, Ke Chen

Issue&Volume: 2025-02-06

Abstract: The use of single-atom catalysts (SACs) with abundant electrocatalytic centers has been identified as the most desirable strategy to inhibit the shuttle effect in lithium-sulfur batteries. However, the co-contribution from SAC and its support via their interactions for accelerating the sulfur reduction reactions (SRR) has so far received little attention, since the underlying mechanism remains elusive. Herein, guided by density functional theory calculations, Cobalt-SACs supported on a graphitic carbon nitride substrate (Co-GCN), are selected to elucidate the co-catalytic role in enhancing the SRR. The inherent high charge polarity of GCN, combined with its unique tri-s-triazine structure, offers multiple binding sites for lithium polysulfides (LiPSs) through Li-N bonds, as well as N/C-coordinated frameworks for anchoring Co-SACs. This structural configuration further amplifies the interaction with LiPSs via Co-S bonds. Consequently, both Co-SACs and GCN actively participate in sulfur reduction electrocatalysis by binding LiPS intermediates, lowering the conversion energy barrier of SRR. Benefitting from such unique synergy, the battery demonstrates outstanding rate performance (718.9 mAh g-1 at 5.0 C) and yields a high areal capacity of up to 13.8 mAh cm-2 (1584.3 mAh g-1) under a high areal sulfur loading of 8.7 mg cm-2 but a low electrolyte/sulfur ratio of 5.0 μL mg-1.

DOI: 10.1002/anie.202425144

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202425144