Atomically Dispersed Unsaturated Cu‐N3 Sites on High‐Curvature Hierarchically Porous Carbon Nanotube for Synergetic Enhanced Nitrate Electroreduction to Ammonia
Atomically Dispersed Unsaturated Cu‐N3 Sites on High‐Curvature Hierarchically Porous Carbon Nanotube for Synergetic Enhanced Nitrate Electroreduction to Ammonia
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DOI：
10.1002/adfm.202302651
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发表时间：
2023-07
影响因子：
19
通讯作者：
Yan Wang;Wenchang Zhang;Weidong Wen;Xinyao Yu;Yuanxin Du;Kun Ni;Yanwu Zhu;Manzhou Zhu
中科院分区：
文献类型：
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作者：
Yan Wang;Wenchang Zhang;Weidong Wen;Xinyao Yu;Yuanxin Du;Kun Ni;Yanwu Zhu;Manzhou Zhu
由于适当的内在活性和 SAC 的优点，铜基单原子催化剂 (SAC) 被认为是硝酸盐电催化还原为氨 (NO3RR) 的有前途的候选者。然而，大多数报道的Cu SAC都是基于4N饱和配位并支撑在平面碳基底上，其性能并不令人满意。在此，通过逐步聚合-表面修饰-静电吸附-碳化策略，在高曲率分级多孔N掺杂碳纳米管（NCNT）上设计并构建了低配位Cu-N3 SAC。 Cu-N3 SAC/NCNT 表现出出色的 NO3RR 性能，最大法拉第效率为 89.64%，NH3 产率高达 30.09 mg mgcat−1 h−1 (70.8 mol gCu−1 h−1)，优于大多数报道的 SAC 和铜基催化剂。硫氰化钾中毒实验、在线微分电化学质谱、原位傅里叶变换红外光谱和密度泛函理论计算结果综合表明：1）不饱和Cu是活性位点； 2）Cu-N3 SACs/NCNT具有NO*-HNO*-H2NO*-H2NOH*途径； 3）低配位Cu-N3位点和高曲率碳载体协同促进反应动力学并降低限速步骤势垒。这项研究启发了一种创造不饱和协调环境和调节支持结构的协同增强催化策略。
Cu‐based single‐atom catalysts (SACs) are regarded as promising candidates for electrocatalytic reduction of nitrate to ammonia (NO3RR) owing to the appropriate intrinsic activity and the merits of SACs. However, most reported Cu SACs are based on 4N saturated coordination and supported on planer carbon substrate, and their performances are unsatisfactory. Herein, low‐coordinated Cu‐N3 SACs are designed and constructed on high‐curvature hierarchically porous N‐doped carbon nanotube (NCNT) via a stepwise polymerization–surface modification–electrostatic adsorption–carbonization strategy. The Cu‐N3 SACs/NCNT exhibits outstanding NO3RR performance with maximal Faradaic efficiency of 89.64% and NH3 yield rate of up to 30.09 mg mgcat−1 h−1 (70.8 mol gCu−1 h−1), superior to most reported SACs and Cu‐based catalysts. The results integrated from potassium thiocyanide poisoning experiments, online differential electrochemical mass spectrometry, in situ Fourier transform infrared spectroscopy, and density functional theory calculations demonstrate: 1) unsaturated Cu is active site; 2) Cu‐N3 SACs/NCNT possesses NO*‐HNO*‐H2NO*‐H2NOH* pathway; 3) low‐coordinated Cu‐N3 sites and high‐curvature carbon support synergetic promote reaction dynamics and reduce rate‐determining step barrier. This study inspires a synergetic enhancement catalysis strategy of creating unsaturated coordination environment and regulating support structure.