Details

Autor(en) / Beteiligte

• Li, Xuning
• Cao, Chang-Su
• Hung, Sung-Fu
• Lu, Ying-Rui
• Cai, Weizheng
• Rykov, Alexandre I.
• Miao, Shu
• Xi, Shibo
• Yang, Hongbin
• Hu, Zehua
• Wang, Junhu
• Zhao, Jiyong
• Alp, Esen Ercan
• Xu, Wei
• Chan, Ting-Shan
• Chen, Haoming
• Xiong, Qihua
• Xiao, Hai
• Huang, Yanqiang
• Li, Jun
• Zhang, Tao
• Liu, Bin

Titel

Identification of the Electronic and Structural Dynamics of Catalytic Centers in Single-Fe-Atom Material

Ist Teil von

• Chem, 2020-12, Vol.6 (12), p.3440-3454

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The lack of model single-atom catalysts (SACs) and atomic-resolution operando spectroscopic techniques greatly limits our comprehension of the nature of catalysis. Herein, based on the designed model single-Fe-atom catalysts with well-controlled microenvironments, we have explored the exact structure of catalytic centers and provided insights into a spin-crossover-involved mechanism for oxygen reduction reaction (ORR) using operando Raman, X-ray absorption spectroscopies, and the developed operando57Fe Mössbauer spectroscopy. In combination with theoretical studies, the N-FeN4C10 moiety is evidenced as a more active site for ORR. Moreover, the potential-relevant dynamic cycles of both geometric structure and electronic configuration of reactive single-Fe-atom moieties are evidenced via capturing the peroxido (∗O2−) and hydroxyl (∗OH−) intermediates under in situ ORR conditions. We anticipate that the integration of operando techniques and SACs in this work shall shed some light on the electronic-level insight into the catalytic centers and underlying reaction mechanism. [Display omitted] •Single-Fe-atom material with controlled microenvironment as efficient ORR catalyst•Operando57Fe Mössbauer spectroscopy developed for the characterization of SACs in ORR•Evidence for electronic and structural dynamics of single-Fe-atom moieties in ORR Single-atom catalysts (SACs) build a conceptual bridge between homo- and heterogeneous catalysis. However, the lack of model SACs and atomic-resolution operando spectroscopic techniques greatly limits our comprehension of the nature of catalysis. Herein, based on the newly designed model single-Fe-atom catalysts, we explored the exact structure of catalytic centers and provided a spin-crossover-involved mechanism for oxygen reduction reaction (ORR) using operando Raman, X-ray absorption spectroscopies, and the newly developed operando57Fe Mössbauer spectroscopy. The potential-relevant electronic and structural dynamic cycles of active single-Fe-atom moieties were evidenced via capturing the ∗O2− and ∗OH− intermediates and further supported by theoretical calculations. These results provide a proof of concept for the integration of operando techniques and SACs, which may direct the way toward the electronic-level insight into the catalytic centers and reaction mechanism. Operando Mössbauer spectroscopy was developed for in situ monitoring the evolution of catalytic centers in single-Fe-atom catalyst under practical oxygen reduction reaction conditions. Combining with operando Raman and X-ray absorption spectroscopies, the potential-relevant electronic and structural dynamic cycles of active single-Fe-atom moieties were evidenced via capturing the ∗O2− and ∗OH− intermediates and further supported by theoretical calculations.