Dynamic Evolution of Solid-Liquid Electrochemical Interfaces over Single-Atom Active Sites
Dynamic Evolution of Solid-Liquid Electrochemical Interfaces over Single-Atom Active Sites
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单原子活性位点固液电化学界面的动态演化
DOI：
10.1021/jacs.0c04231
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发表时间：
2020-07-15
影响因子：
15
通讯作者：
Liu, Qinghua
中科院分区：
文献类型：
--
作者：
Su, Hui;Zhou, Wanlin;Liu, Qinghua
固液界面的结构动力学决定了所有电化学过程的化学性质。在这里，通过结合多个操作同步辐射光谱，我们确定在原子水平上的一般演变的单原子镍在SLEIs到一个近自由原子状态的电化学氧还原反应（ORR）。我们发现，在SLEI的单原子Ni往往是动态释放的氮-碳基板，然后形成一个接近自由，孤立的锯齿形活性位（Ni 1（2-delta）+N2）在反应过程中。这种孤立的锯齿形Ni 1（2-delta）+N2活性位点促进O-2吸附和解离成双电层内的关键 *O中间体，实现了迄今为止报道的在碱性溶液中具有最佳ORR性能的高效单原子催化剂。这些发现可能为解剖SLEIs的其他重要结构动力学过程（如析氢、析氧和CO2还原反应）铺平了一般道路。
The structural dynamics of the solid-liquid interfaces (SLEIs) determines the chemistry in all electrochemical processes. Here, by combining multiple operando synchrotron spectroscopies, we identify at the atomic level a general evolution of single-atom Ni at SLEIs into a near-free atom state in the electrochemical oxygen reduction reaction (ORR). We uncover that the single-atom Ni at SLEIs tends to be dynamically released from the nitrogen-carbon substrate and then forms a near-free, isolated-zigzag active site (Ni1(2-delta)+N2) during the reaction. This isolated-zigzag Ni1(2-delta)+N2 active site facilitates the adsorption and dissociation of O-2 into a crucial *O intermediate within the electrical double layers, realizing a highly efficient single-atom catalyst with the best ORR performance in alkaline solutions reported thus far. These findings may pave a general way for dissecting other important structural dynamic processes at SLEIs, such as hydrogen evolution, oxygen evolution, and CO2 reduction reactions.