Wen Guobin, Ren Bohua, Park Moon G, Yang Jie, Dou Haozhen, Zhang Zhen, Deng Ya-Ping, Bai Zhengyu, Yang Lin, Gostick Jeff, Botton Gianluigi A, Hu Yongfeng, Chen Zhongwei
School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, 453007, China.
Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute for Sustainable Energy, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
Angew Chem Int Ed Engl. 2020 Jul 27;59(31):12860-12867. doi: 10.1002/anie.202004149. Epub 2020 Jun 3.
Simultaneously improving energy efficiency (EE) and material stability in electrochemical CO conversion remains an unsolved challenge. Among a series of ternary Sn-Ti-O electrocatalysts, 3D ordered mesoporous (3DOM) Sn Ti O achieves a trade-off between active-site exposure and structural stability, demonstrating up to 71.5 % half-cell EE over 200 hours, and a 94.5 % Faradaic efficiency for CO at an overpotential as low as 430 mV. DFT and X-ray absorption fine structure analyses reveal an electron density reconfiguration in the Sn-Ti-O system. A downshift of the orbital band center of Sn and a charge depletion of Ti collectively facilitate the dissociative adsorption of the desired intermediate COOH* for CO formation. It is also beneficial in maintaining a local alkaline environment to suppress H and formate formation, and in stabilizing oxygen atoms to prolong durability. These findings provide a new strategy in materials design for efficient CO conversion and beyond.
在电化学CO转化过程中，同时提高能量效率（EE）和材料稳定性仍然是一个尚未解决的挑战。在一系列三元Sn-Ti-O电催化剂中，三维有序介孔（3DOM）Sn Ti O在活性位点暴露和结构稳定性之间实现了平衡，在200小时内半电池EE高达71.5%，在低至430 mV的过电位下，CO的法拉第效率为94.5%。密度泛函理论（DFT）和X射线吸收精细结构分析揭示了Sn-Ti-O系统中的电子密度重新配置。Sn的轨道带中心下移和Ti的电荷耗尽共同促进了所需中间体COOH*的解离吸附，以形成CO。这也有利于维持局部碱性环境以抑制H和甲酸盐的形成，并稳定氧原子以延长耐久性。这些发现为高效CO转化及其他领域的材料设计提供了新策略。
