Selective Four‐Electron Reduction of Oxygen by a Nonheme Heterobimetallic CuFe Complex
Hongtao Zhang, Fei Xie, Yu‐Hua Guo, Yao Xiao, Ming‐Tian Zhang
Abstract
Abstract We report herein the first nonheme CuFe oxygen reduction catalyst ([Cu II (bpbp)( μ ‐OAc) 2 Fe III ] 2+ , CuFe−OAc ), which serves as a functional model of cytochrome c oxidase and can catalyze oxygen reduction to water with a turnover frequency of 2.4×10 3 s −1 and selectivity of 96.0 % in the presence of Et 3 NH + . This performance significantly outcompetes its homobimetallic analogues (2.7 s −1 of CuCu−OAc with %H 2 O 2 selectivity of 98.9 %, and inactive of FeFe−OAc ) under the same conditions. Structure‐activity relationship studies, in combination with density functional theory calculation, show that the CuFe center efficiently mediates O−O bond cleavage via a Cu II ( μ ‐ η 1 : η 2 ‐O 2 )Fe III peroxo intermediate in which the peroxo ligand possesses distinctive coordinating and electronic character. Our work sheds light on the nature of Cu/Fe heterobimetallic cooperation in oxygen reduction catalysis and demonstrates the potential of this synergistic effect in the design of nonheme oxygen reduction catalysts.