Gege Yang1, Jiawei Zhu2,3, Pengfei Yuan4, Yongfeng Hu5, Gan Qu1, Bang-An Lu1, Xiaoyi Xue1, Hengbo Yin1, Wenzheng Cheng1, Junqi Cheng1, Wenjing Xu1, Jin Li1, Jinsong Hu6, Shichun Mu7,8, Jia-Nan Zhang9. 1. College of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, PR China. 2. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, PR China. 3. Foshan Xianhu Laboratory, Foshan, 528200, PR China. 4. International Joint Research Laboratory for Quantum Functional Materials of Henan Province, and School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, 450001, PR China. 5. Canadian Light Source, 44 Innovation Blvd, Saskatoon, SK, S7N 2V3, Canada. 6. Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Nanostructure and Nanotechnology Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China. 7. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, PR China. msc@whut.edu.cn. 8. Foshan Xianhu Laboratory, Foshan, 528200, PR China. msc@whut.edu.cn. 9. College of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, PR China. zjn@zzu.edu.cn.
Abstract
As low-cost electrocatalysts for oxygen reduction reaction applied to fuel cells and metal-air batteries, atomic-dispersed transition metal-nitrogen-carbon materials are emerging, but the genuine mechanism thereof is still arguable. Herein, by rational design and synthesis of dual-metal atomically dispersed Fe,Mn/N-C catalyst as model object, we unravel that the O2 reduction preferentially takes place on FeIII in the FeN4 /C system with intermediate spin state which possesses one eg electron (t2g4eg1) readily penetrating the antibonding π-orbital of oxygen. Both magnetic measurements and theoretical calculation reveal that the adjacent atomically dispersed Mn-N moieties can effectively activate the FeIII sites by both spin-state transition and electronic modulation, rendering the excellent ORR performances of Fe,Mn/N-C in both alkaline and acidic media (halfwave positionals are 0.928 V in 0.1 M KOH, and 0.804 V in 0.1 M HClO4), and good durability, which outperforms and has almost the same activity of commercial Pt/C, respectively. In addition, it presents a superior power density of 160.8 mW cm-2 and long-term durability in reversible zinc-air batteries. The work brings new insight into the oxygen reduction reaction process on the metal-nitrogen-carbon active sites, undoubtedly leading the exploration towards high effective low-cost non-precious catalysts.
As low-cost electrocatalysts for n class="Chemical">oxygen reduction reaction applied to fuel cells and metal-air batteries, atomic-dispersed transition metal-nitrogen-carbon materials are emerging, but the genuine mechanism thereof is still arguable. Herein, by rational design and synthesis of dual-metal atomically dispersed Fe,Mn/N-C catalyst as model object, we unravel that the O2 reduction preferentially takes place on FeIII in the FeN4 /C system with intermediate spin state which possesses one eg electron (t2g4eg1) readily penetrating the antibonding π-orbital of oxygen. Both magnetic measurements and theoretical calculation reveal that the adjacent atomically dispersed Mn-N moieties can effectively activate the FeIII sites by both spin-state transition and electronic modulation, rendering the excellent ORR performances of Fe,Mn/N-C in both alkaline and acidic media (halfwave positionals are 0.928 V in 0.1 M KOH, and 0.804 V in 0.1 M HClO4), and good durability, which outperforms and has almost the same activity of commercial Pt/C, respectively. In addition, it presents a superior power density of 160.8 mW cm-2 and long-term durability in reversible zinc-air batteries. The work brings new insight into the oxygen reduction reaction process on the metal-nitrogen-carbon active sites, undoubtedly leading the exploration towards high effective low-cost non-precious catalysts.
Authors: Talha Al-Zoubi; Yu Zhou; Xi Yin; Blanka E Janicek; Cheng-Jun Sun; Charles E Schulz; Xiaohui Zhang; Andrew A Gewirth; Pinshane Y Huang; Piotr Zelenay; Hong Yang Journal: J Am Chem Soc Date: 2020-03-02 Impact factor: 15.419
Authors: Jesús Barrio; Angus Pedersen; Jingyu Feng; Saurav Ch Sarma; Mengnan Wang; Alain Y Li; Hossein Yadegari; Hui Luo; Mary P Ryan; Maria-Magdalena Titirici; Ifan E L Stephens Journal: J Mater Chem A Mater Date: 2022-02-11