"Hot edges" in an inverse opal structure enable efficient CO2 electrochemical reduction and sensitive in situ Raman characterization
"Hot edges" in an inverse opal structure enable efficient CO2 electrochemical reduction and sensitive in situ Raman characterization
复制标题
反蛋白石结构中的“热边缘”可实现高效的 CO2 电化学还原和灵敏的原位拉曼表征
DOI：
10.1039/c9ta02288k
复制
发表时间：
2019
影响因子：
11.9
通讯作者：
Zhang Liwu
中科院分区：
文献类型：
--
作者：
Yang Yang;Ohnoutek Lukas;Ajmal Saira;Zheng Xiuzhen;Feng Yiqing;Li Kejian;Wang Tao;Deng Yue;Liu Yangyang;Xu Dong;Valev Ventsislav K.;Zhang Liwu
通过电还原将CO2转化为燃料和化学品已经引起了极大的兴趣。通过介观结构的设计来调节电极中的电场分布，证明了具有反蛋白石（CI-1-IO）结构的Cu-In合金提供了有效的电化学CO2还原，并且允许通过表面增强拉曼散射灵敏地检测CO2还原中间体。CI-1-IO表面上中间体的拉曼信号的显著增强可以归因于反蛋白石结构的“热边缘”上的电场增强。此外，在CI-1-IO电极上，在-0.6 V vs. RHE下实现了92%的最高CO2还原法拉第效率（FE）（甲酸盐和CO的总和）。漫反射红外光谱（DRIFTS）结果表明，具有反蛋白石结构的Cu-In合金对CO2具有更快的吸附动力学和更高的吸附容量。碗状结构的“热边缘”由于高曲率而集中电场，并且还将K+集中在活性位点上，这可以降低CO2还原反应的能垒。这项研究为设计有效的CO2转化材料和检测CO2还原过程中的中间产物提供了新的见解。
Conversion of CO2 into fuels and chemicals via electroreduction has attracted significant interest. Via mesostructure design to tune the electric field distribution in the electrode, it is demonstrated that the Cu–In alloy with an inverse opal (CI-1-IO) structure provides efficient electrochemical CO2 reduction and allows for sensitive detection of the CO2 reduction intermediates via surface-enhanced Raman scattering. The significant enhancement of Raman signals of the intermediates on the CI-1-IO surface can be attributed to electric field enhancement on the “hot edges” of the inverse opal structure. Additionally, a highest CO2 reduction faradaic efficiency (FE) of 92% (sum of formate and CO) is achieved at −0.6 V vs. RHE on the CI-1-IO electrode. The diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results show that the Cu–In alloy with an inverse opal structure has faster adsorption kinetics and higher adsorption capacity for CO2. The “hot edges” of the bowl-like structure concentrate electric fields, due to the high curvature, and also concentrate K+ on the active sites, which can lower the energy barrier of the CO2 reduction reaction. This research provides new insight into the design of materials for efficient CO2 conversion and the detection of intermediates during the CO2 reduction process.