Operando XAS study of Transition Metal - Bismuth Dual Atom Catalysts

Understanding the mechanism of electron transfer from coupled dual-atom catalyst (DACs) active sites to reactants is critical for designing more efficient catalysts, particularly for applications like lithium-sulfur batteries (LSBs). To investigate how coupling affects electron transfer and to determine the electronic structure of the active center and its interaction with polysulfides within the LSB cathode, we synthesized a series of 3d transition metal (TM) single atoms (Mn, Fe, Co, Ni, Cu, Zn) coupled with single-atom Bi on a carbon nitride (CN) framework and tested them as sulfur hosts in LSB cathodes. To elucidate the electronic transfer between these TM single atoms and Bi, and to understand the catalytic role of TM-Bi coupling in polysulfide conversion, we propose a systematic operando X-ray absorption spectroscopy (XAS) study alongside operando X-ray diffraction (XRD) measurements. XAS will reveal the local environment of the DACs and shed light on the electron transfer process, while XRD will track the crystalline structure changes of sulfur species, providing insights into the polysulfide conversion process across different catalysts. The combined use of these techniques offers complementary information, integrating both the local environment and crystalline perspectives under realistic working conditions. This approach could yield valuable insights into the rational design of polysulfide catalysts to enhance the durability of LSBs.