文献类型：期刊文献

英文题名：OER activity manipulated by IrO6 coordination geometry: an insight from pyrochlore iridates

作者：Sun, Wei[1];Liu, Ji-Yuan[2,3];Gong, Xue-Qing[2,3];Zaman, Waqas-Qamar[1];Cao, Li-Mei[1];Yang, Ji[1]

机构：[1]East China Univ Sci & Technol, Sch Resources & Environm Engn, State Environm Protect Key Lab Environm Risk Asse, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Ctr Computat Chem, Key Lab Adv Mat, 130 Meilong Rd, Shanghai 200237, Peoples R China;[3]East China Univ Sci & Technol, Res Inst Ind Catalysis, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2016

卷号：6

外文期刊名：SCIENTIFIC REPORTS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000389085300003)】；

基金：This research is based on work supported by the National Natural Science Foundation of China (21177037, 21277045, and 21322307).

语种：英文

摘要：The anodic reaction of oxygen evolution reaction (OER), an important point for electrolysis, however, remains the obstacle due to its complicated reaction at electrochemical interfaces. Iridium oxide (IrO2) is the only currently known 5d transition metal oxide possessing admirable OER activity. Tremendous efforts have been carried out to enhance the activity of iridium oxides. Unfortunately there lies a gap in understanding what factors responsible for the activity in doped IrO2 or the novel crystal structure. Based on two metallic pyrochlores (Bi2Ir2O7 and Pb2Ir2O6.5) and IrO2. It has been found that there exists a strong correlation between the specific OER activity and IrO6 coordination geometry. The more distortion in IrO6 geometry ascends the activity of Ir sites, and generates activity order of Pb-Ir > IrO2 > Bi-Ir. Our characterizations reveal that distorted IrO6 in Pb-Ir induces a disappearance of J = 1/2 subbands in valence band, while Bi-Ir and IrO2 resist this nature probe. The performed DFT calculations indicated the distortion in IrO6 geometry can optimize binding strength between Ir-5d and O-2p due to broader d band width. Based on this insight, enhancement in OER activity is obtained by effects that change IrO6 octahedral geometry through doping or utilizing structural manipulation with nature of distorted octahedral coordination.