文献类型：期刊文献

英文题名：An efficiently tuned d-orbital occupation of IrO2 by doping with Cu for enhancing the oxygen evolution reaction activity

作者：Sun, Wei[1];Song, Ya[2,3];Gong, Xue-Qing[2,3];Cao, Li-mei[1];Yang, Ji[1]

机构：[1]E China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Sch Resources & Environm Engn, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Key Lab Adv Mat, Ctr Computat Chem, Shanghai 200237, Peoples R China;[3]E China Univ Sci & Technol, Res Inst Ind Catalysis, Shanghai 200237, Peoples R China

年份：2015

卷号：6

期号：8

起止页码：4993

外文期刊名：CHEMICAL SCIENCE

收录：;EI(收录号：20153001060680);WOS:【SCI-EXPANDED(收录号:WOS:000357931700075)】；

基金：This research is based on work supported by the National Natural Science Foundation of China (21177037, 21277045, 21322307), the Public welfare project of the Ministry of Environmental Protection (201309021), the "Shu Guang" project of the Shanghai Municipal Education Commission and the Shanghai Education Development Foundation, and the Fundamental Research Funds for the Central Universities. We would like to thank beamline BL14W1 (Shanghai Synchrotron Radiation Facility) for providing the beam time.

语种：英文

外文关键词：Copper - Transition metal oxides - Energy conversion - Oxygen - Copper oxides - Density functional theory - Free energy - Catalysts

摘要：The oxygen evolution reaction (OER) has been regarded as a key half reaction for energy conversion technologies and requires high energy to create O=O bonds. Transition metal oxides (TMOs) seem to be a promising and appealing solution to the challenge because of the diversity of their d-orbital states. We chose IrO2 as a model because it is universally accepted as a current state-of-the-art OER catalyst. In this study, copper-doped IrO2, particularly Cu0.3Ir0.7O delta, is shown to significantly improve the OER activity in acidic, neutral and basic solutions compared to un-doped IrO2. The substituted amount of Cu in IrO2 has a limit described by the Cu0.3Ir0.7O delta composition. We determined that the performance of Cu0.3Ir0.7O delta is due primarily to an increase in the Jahn-Teller effect in the CuO6 octahedra, and partially to oxygen defects in the lattice induced by the IrO6 octahedral geometric structure distortions, which enhance the lift degeneracy of the t(2g) and e(g) orbitals, making the d(z)(2) orbital partially occupied. This phenomenon efficiently reduces the difference between Delta G2 and Delta G3 in the free energy from the density functional theoretical (DFT) calculations and can yield a lower theoretical overpotential comparable to that of IrO2. The proposed method of doping with foreign elements to tune the electron occupation between the t(2g) and e(g) orbital states of Ir creates an opportunity for designing effective OER catalysts using the TMO groups.