Crucial Role of Surface Hydroxyls on the Activity and Stability in Electrochemical CO2 Reduction

作者：Wanyu Deng, Lei Zhang, Lulu Li, Sai Chen, Congling Hu, Zhi‐Jian Zhao, Tuo Wang, Jinlong Gong · 发表于：Journal of the American Chemical Society · 年份：2019 · DOI：10.1021/jacs.8b13786 · 被引用次数：343 · 研究领域：CO2 Reduction Techniques and Catalysts、Ionic liquids properties and applications、Advanced battery technologies research

The role of surface hydroxyls is significant for understanding catalytic performance of metallic oxides for CO 2 electroreduction reaction (CO 2 ER). This Communication describes, employing SnO x as a model system, how to moderate coverage of hydroxyl to derive a stable Sn branches catalyst for CO 2 ER with a 93.1% Faradaic efficiency (FE) of carbonaceous products. With use of in situ attenuated total reflection surface enhanced infrared adsorption spectroscopy (ATR-SEIRAS) and density functional theory (DFT) calculations, we found that a proper amount of surface hydroxyls offered effective sites to boost CO 2 adsorption via hydrogen bond. However, a higher surface coverage of hydroxyls leads to self-reduction of Sn–OH. We also explained the competition between self-reduction and CO 2 reduction over Sn-based catalysts. The findings revealed the quantitative correlation between surface coverage of hydroxyl and CO 2 ER activity and suggested a logical extension to other metal oxide catalysts for CO 2 ER.