Dynamics at Polarized Carbon Dioxide-Iron Oxyhydroxide Interfaces Unveil the Origin of Multicarbon Product Formation
Dynamics at Polarized Carbon Dioxide-Iron Oxyhydroxide Interfaces Unveil the Origin of Multicarbon Product Formation
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DOI：
10.1021/acscatal.1c04296
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发表时间：
2022-01-07
期刊：
影响因子：
12.9
通讯作者：
Centi, Gabriele
中科院分区：
文献类型：
--
作者：
Arrigo, Rosa;Blume, Raoul;Centi, Gabriele
表面敏感的常压X射线光电子能谱和近边X射线吸收精细结构光谱与电催化活性研究、多尺度电子显微镜和理论模拟相结合，为在掺氮碳负载氢氧化铁催化剂上二氧化碳气相选择性还原合成异丙醇提供了深入的见解。溶解的原子碳通过化学吸附在类铁水石相表面的一氧化碳的还原而形成二氧化碳还原的相应电位。理论模拟表明，氢氧化铁结构允许附近的一氧化碳化学吸附在适当的几何排列中进行耦合。根据我们的观察，我们提出了一种三碳原子产物的形成机制，即在阴极极化的情况下，在氢阳离子存在的情况下，原子碳经历氢化的中间形成。这种机制只有在石墨载体的边缘平面上配位的薄的类铁水合纳米结构的情况下才有效，那里的氮边缘位置稳定了这些物种，并降低了反应的过电位。较大的类铁氢氧化铁纳米颗粒对电子传输无效。
Surface-sensitive ambient pressure X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy combined with an electrocatalytic reactivity study, multilength-scale electron microscopy, and theoretical modeling provide insights into the gas-phase selective reduction of carbon dioxide to isopropanol on a nitrogen-doped carbon-supported iron oxyhydroxide electrocatalyst. Dissolved atomic carbon forms at relevant potentials for carbon dioxide reduction from the reduction of carbon monoxide chemisorbed on the surface of the ferrihydrite-like phase. Theoretical modeling reveals that the ferrihydrite structure allows vicinal chemisorbed carbon monoxide in the appropriate geometrical arrangement for coupling. Based on our observations, we suggest a mechanism of three-carbon-atom product formation, which involves the intermediate formation of atomic carbon that undergoes hydrogenation in the presence of hydrogen cations upon cathodic polarization. This mechanism is effective only in the case of thin ferrihydrite-like nanostructures coordinated at the edge planes of the graphitic support, where nitrogen edge sites stabilize these species and lower the overpotential for the reaction. Larger ferrihydrite-like nanoparticles are ineffective for electron transport.