Tailoring Electron‐Riched Boron Sites in BCN for Nitrogen Fixation via Alternate Mechanism
Tailoring Electron‐Riched Boron Sites in BCN for Nitrogen Fixation via Alternate Mechanism
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DOI：
10.1002/admi.202101842
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发表时间：
2022-01
影响因子：
5.4
通讯作者：
Yutong Yang;Yin Wang;Xia Wang;Shao-Qing Chen;Limei Duan;Wei Zhang;Wanfei Li;Jinghai Liu
中科院分区：
文献类型：
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作者：
Yutong Yang;Yin Wang;Xia Wang;Shao-Qing Chen;Limei Duan;Wei Zhang;Wanfei Li;Jinghai Liu
电化学氮还原反应（eNRR）有望在温和条件下实现可持续的氨（NH3）生产。然而，它仍然受到氮活化以及与析氢反应的强烈竞争的挑战。研究表明，微调硼碳氮化物（BCN）固体催化剂上硼（B）位点的局部电子密度对 eNRR 活性和选择性具有显着影响。 BCN 催化剂上富电子 B 位点的浓度是由固态反应介导的，其电子结构通过电子能量损失谱 (EELS) 和电子顺磁共振 (EPR) 得到证实。通过密度泛函理论 (DFT) 计算，富电子 B 位点处的氮 (N2) 活化和还原是通过替代途径进行的，其决定步骤能量仅为 0.92 eV。优化后的BCN5催化剂具有最高比例的富电子B位，实现了29.3 µg h−1 mg−1cat的出色NH3产率和39%的最高法拉第效率。
The electrochemical nitrogen reduction reaction (eNRR) is promising for achieving sustainable ammonia (NH3) production under mild conditions. However, it is still challenged by nitrogen activation and strong competition with the hydrogen evolution reaction. Here, it is revealed that fine‐tuning the local electron density of boron (B) sites at the boron carbon nitride (BCN) solid catalysts has significant effects on the eNRR activity and selectivity. The concentration of electron‐rich B sites at BCN catalysts are mediated by solid‐state reaction, where their electronic structures are confirmed by electron energy‐loss spectroscopy (EELS) and electron paramagnetic resonance (EPR). Over the density functional theory (DFT) calculations, the nitrogen (N2) activation and reduction at an electron‐riched B site is through an alternate pathway with the determining‐step energy of only 0.92 eV. The optimized BCN5 catalyst with the highest ratio of electron‐riched B sites achieves an outstanding NH3 production rate of 29.3 µg h−1 mg−1cat and the highest Faradaic efficiency of 39%.