Atomically dispersed Fe3+ sites catalyze efficient CO2 electroreduction to CO
Atomically dispersed Fe3+ sites catalyze efficient CO2 electroreduction to CO
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DOI：
10.1126/science.aaw7515
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发表时间：
2019-06-14
期刊：
影响因子：
56.9
通讯作者：
Hu, Xile
中科院分区：
文献类型：
--
作者：
Gu, Jun;Hsu, Chia-Shuo;Hu, Xile
目前，用于将CO2转化为CO的最活跃的电催化剂是基于金的纳米材料，而非贵金属催化剂显示出低至中等的活性。在这里，我们报告的催化剂分散的单原子铁网站，产生CO的过电位低至80毫伏。在340毫伏的过电位下，局部电流密度达到每平方厘米94毫安。操作X射线吸收光谱显示活性位点是离散的Fe 3+离子，与N掺杂的碳载体的吡咯氮（N）原子配位，其在电催化期间保持其+3氧化态，可能通过与导电碳载体的电子耦合。电化学数据表明，Fe 3+网站获得其上级活动从更快的CO2吸附和较弱的CO吸附比传统的Fe 2+网站。
Currently, the most active electrocatalysts for the conversion of CO2 to CO are gold-based nanomaterials, whereas non-precious metal catalysts have shown low to modest activity. Here, we report a catalyst of dispersed single-atom iron sites that produces CO at an overpotential as low as 80 millivolts. Partial current density reaches 94 milliamperes per square centimeter at an overpotential of 340 millivolts. Operando x-ray absorption spectroscopy revealed the active sites to be discrete Fe3+ ions, coordinated to pyrrolic nitrogen (N) atoms of the N-doped carbon support, that maintain their +3 oxidation state during electrocatalysis, probably through electronic coupling to the conductive carbon support. Electrochemical data suggest that the Fe3+ sites derive their superior activity from faster CO2 adsorption and weaker CO absorption than that of conventional Fe2+ sites.