Tuning the p-Orbital Electron Structure of s-Block Metal Ca Enables a High-Performance Electrocatalyst for Oxygen Reduction
Tuning the p-Orbital Electron Structure of s-Block Metal Ca Enables a High-Performance Electrocatalyst for Oxygen Reduction
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调节 s 区金属 Ca 的 p 轨道电子结构可实现高性能氧还原电催化剂
DOI：
10.1002/adma.202107103
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发表时间：
2021-10-11
影响因子：
29.4
通讯作者：
Chen, Qianwang
中科院分区：
文献类型：
--
作者：
Lin, Zhiyu;Huang, Hao;Chen, Qianwang
以前的努力大多致力于发展过渡金属作为电催化剂的d带中心模型的指导下。到目前为止，周期表中s区的金属在氧还原反应（ORR）的应用中很少受到关注。本文报道了一种钙（Ca）单原子与N和O配位的碳催化剂，其在酸性条件（E-1/2 = 0.77 V，0.1 m HClO 4）和碱性条件（E-1/2 = 0.90 V，0.1 m KOH）下均显示出优异的ORR活性。在锌空气电池中，Ca-N，O/C催化剂的最大功率密度为218 mW cm（-2），比目前已报道的一系列催化剂性能好上级。X射线吸收近边结构（XANES）表征证实了在碳基质中形成N-和O-原子配位的Ca。密度泛函理论（DFT）计算结果表明，主族Ca的高催化活性归因于其p轨道电子结构受N和O配位的调节，使Ca原子的投影态密度（PDOS）的最高峰（E-P）移近费米能级，从而促进了ORR中间体的吸附和电子转移.
Most previous efforts are devoted to developing transition metals as electrocatalysts guided by the d-band center model. The metals of the s-block of the periodic table have so far received little attention in the application of oxygen reduction reactions (ORR). Herein, a carbon catalyst with calcium (Ca) single atom coordinated with N and O is reported, which displays exceptional ORR activities in both acidic condition (E-1/2 = 0.77 V, 0.1 m HClO4) and alkaline condition (E-1/2 = 0.90 V, 0.1 m KOH). The Ca-N, O/C exhibits remarkable performance in zinc-air battery with a maximum power density of 218 mW cm(-2), superior to a series of catalysts reported so far. X-ray absorption near-edge structure (XANES) characterization confirms the formation of N- and O-atom-coordinated Ca in the carbon matrix. Density functional theory (DFT) calculations reveal that the high catalytic activity of main-group Ca is ascribed to the fact that its p-orbital electron structure is regulated by N and O coordination so that the highest peak (E-P) of the projected density of states (PDOS) for the Ca atom is moved close to the Fermi level, thereby facilitating the adsorption of ORR intermediates and electron transfer.