摘要
Precisely designing atomic metal-nitrogen-carbon(M-N-C)catalysts with asymmetric diatomic configurations and studying their structure–activity relationships for oxygen reduction reaction(ORR)are important for zinc-air batteries(ZABs).Herein,a dualatomic-site catalyst(DASC)with CoN_(3)S-MnN_(2)S_(2) configuration was prepared for the cathodes of ZABs.Compared with Co-N-C(Mn-free)and CoMn-N-C(S-free doping),CoMn-N/S-C exhibits excellent half-wave potential(0.883 V)and turnover frequency(1.54 e·s^(−1)·site^(−1)),surpassing most of the reported state-of-the-art Pt-free ORR catalysts.The CoMn-N/S-C-based ZABs achieve extremely high specific capacity(959 mAh·g^(−1))and good stability(350 h@5 mA·cm^(−2)).Density functional theory(DFT)calculation shows that the introduction of Mn and S can break the electron configuration symmetry of the original Co 3d orbital,lower the dband center of the Co site,and optimize the desorption behavior of*OH intermediate,thereby increasing the ORR activity.
基金
supported by the National Key Research and Development Program of China(No.2020YFB1506300)
the National Natural Science Foundation of China(Nos.21922502,22075018,and 22375017)
Young Elite Scientists Sponsorship Program by BAST(No.BYESS2023163)
CNPC Innovation Found(No.2022DQ02-0606)
Institute of High Energy Physics,Chinese Academy of Sciences for synchrotron radiation(BSRF)testing,Beijing Institute of Technology Research Fund Program,and Analysis and Testing Center of Beijing Institute of Technology.
