Single-Layer Oxygen Deficiency δ-MnO2 for Electrochemical CO2 Reduction

Abstract

电催化还原二氧化碳成多碳燃料一直是研究的热点. 而找到活性高,选择性优,稳定性好的催化剂一直是研究者们奋斗的目标. 二氧化锰因其独特的物理和化学性质被广泛的应用于电催化领域,而缺陷的调控可以改变催化剂的电子性质,在此次工作中作者系统地研究了在有氧缺陷和没有氧缺陷的二维二氧化锰上的电催化二氧化碳还原反应. 通过利用自旋极化密度泛函理论,作者分别计算了他们的电子性质和分子在吸附过程中的能量值. 结果显示,缺陷的引入改变了二氧化锰的特性,使其从半导体性质变为半金属性质,从而提高催化剂的导电性. 同时,分析能量图也很容易发现对应产品的选择性也发生了变化. 二氧化锰有利于甲酸的产生,而氧缺陷的二氧化锰更有利于一氧化碳的生成. 本研究将为二氧化碳还原的其他非贵金属氧化物催化剂的结构设计和优化提供一定的指导.   Manganese dioxide (MnO2) has been widely used in catalysis. In addition, since the defect engineering can change the electronic properties of the catalyst, here we have systematically studied electrocatalytic carbon dioxide reduction reaction (CO2RR) on δ-MnO2 with and without oxygen deficiency, denoted as Ov-MnO2 and MnO2, respectively. We calculate the electronic properties and the intermediate of free energy for MnO2 and Ov-MnO2 with the help of spin-polarized density functional theory. By analyzing this result, we can find that the introduction of defects change the δ-MnO2 from semiconducting properties to semi-metallic properties, leading to the improved conductivity. At the same time, the selectivity of the product has also been changed. MnO2 and Ov-MnO2 are more conducive to the productions of formic acid (HCOOH) and carbon monoxide (CO), respectively. Strikingly, this study will provide guidance in the structural design and optimization of other non-noble metal oxides catalysts for CO2RR.  This work was supported by the National Natural Science Foundation of China (Grant No. 51302079 and U1510103), and the Natural Science Foundation of Hunan Province (Grant No. 2017JJ1008).作者联系地址:(1. 湖南大学物理与微电子科学学院,湖南 长沙 410082; 2. 山西大学分子科学研究所, 山西省能源转化和存储材料重点实验室, 山西 太原 030006; 3. 西安科技大学先进电化学能源学院, 陕西 西安 710048; 4. 长沙秀曦科技公司材料数据中心, 湖南 长沙 410082)Author's Address: 1. School of Physics and Electronics, Hunan University, Changsha 410082, China; 2. Institute of  Molecular Science, Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Shanxi University, Taiyuan 030006, China; 3. Institute of Advanced Electrochemical Energy, Xi’an University of Technology, Xi’an 710048, Shaanxi, China; 4. Material Data Centre, Changsha Xiuxi Technology Co. Ltd., Changsha 410082, China通讯作者E-mail:[email protected]

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