A Perspective on the Rational Design of Spinel Catalysts for Polysulfide Conversion

Abstract

Figure 1. Illustration of normal spinel, inverse spinel, and defected inverse spinel structures. Figure 2. Illustration of d-orbitals splitting in (a) octahedral field and (b) tetrahedral field. Figure 3. Schematic illustration of the role of spin state and M-O covalency in regulating the polysulfide conversion activity of spinel oxides. (a) The role of spin state in regulating the bonding and antibonding states of molecular orbitals between metal cations and sulfur species. (b) The optimized structures of the (111) plane of spinel oxides. The right box shows that one oxygen atom is connected to one tetrahedral cation and two octahedral cations. (c) Illustration of different M_Oct–O–M_Td covalencies and their corresponding active sites in spinel oxides. The top box indicates that the M_Td- active sites are more likely to be generated when the covalency of M_Td–O is weaker than that of M_Oct–O. Otherwise, M_Oct– active sites are more likely to be generated, as shown in the bottom box. [Reproduced with permission from ref (14). Copyright 2020, Springer Nature.] (d) Illustration of the role of M–O covalency in regulating the electron distribution after bond breakage. A weak M–O covalency leads to an unequal distribution of electrons after bond breakage and the generation of two partially ionic parts. In contrast, a strong M–O covalency makes bond breakage more difficult. Only intermediate M–O covalency contributes to the equal distribution of electrons after bond breakage and the exposure of active sites. [Reproduced with permission from ref (14). Copyright 2020, Springer Nature.] Figure 4. Schematic illustration of the design strategies of spinel catalysts. (a) Illustration of site occupancy switch in spinel structures by adjusting the annealing temperature. X indicates anions (e.g., O, S). [Reproduced with permission from ref (3). Copyright 2025, American Chemical Society, Washington, DC.] (b) The role of doping in regulating the valence electrons of metal and lattice sulfur sites of spinel sulfides. [Reproduced with permission from ref (23). Copyright 2025, Wiley-VCH.] (c) The evolution of Co³⁺ spin state and the construction of Co–O–Co spin channel. [Reproduced with permission from ref (24). Copyright 2021, Wiley-VCH.] (d) Illustration of the adsorption–conversion process of polysulfides on the surface of CoFeMnO YSNCs. [Reproduced with permission from ref (18). Copyright 2022, Wiley-VCH.] Figure 5. Outlook and perspectives on the rational design of spinel catalysts for polysulfide conversion. The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/accountsmr.5c00092. Additional discussion on spinel structure, cation coordination environment and spin state, and M–O covalency (PDF) A Perspective on the Rational Design of Spinel Catalysts for Polysulfide Conversion 2 views 0 shares 0 downloads Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html. Z.J.X. and W.X. conceived the topic. W.X. wrote the draft. Z.J.X. and Q.W. revised the manuscript. Wen Xie is a Ph.D. candidate at Energy Research Institute @ Nanyang Technological University, Nanyang Technological University, Singapore. She received her B.S. degree from Northwestern Polytechnical University, China. Her research interests focus on the design spinel catalysts for polysulfide conversion in Li–S batteries. Qian Wu is a Research Fellow at School of Material Science and Engineering, Nanyang Technological University, Singapore. She received her Ph.D. from Shandong University, China. Her research focuses on exploring the fundamental mechanisms of electrocatalytic activity and developing innovative electrocatalysts for clean energy conversion. Zhichuan J. Xu is a President’s Chair Professor at the School of Materials Science and Engineering, Nanyang Technological University, and a Fellow of the Academy of Engineering, Singapore. He received his B.S. degree and Ph.D. from Lanzhou University, China. His major research interests lie in the fields of catalysis and related materials. This work was supported by Singapore Ministry of Education Tier 2 Grant (No. MOE-T2EP10223-0006) and Tier 1 Grant (No. RG91/23). This article references 29 other publications. This article has not yet been cited by other publications.