Salle 5, Site Marcelin Berthelot
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Abstract

Single atom catalysts (SACs) can offer appealing catalytic activity and selectivity for heterogeneous catalysis in general, [1] and for electrocatalysis for energy conversion devices in particular. [ 2] This presentation will describe some examples of studies on the aspects of synthesis, structural characterization and catalytic properties of Metal-Nitrogen-Carbon SACs for fuel cells, electrochemical H2O2 production andCO2 conversion. In many of these potential applications, Metal-Nitrogen-Carbon catalysts (with non-precious metal center) are however competing with precious metal-based catalysts, and the benefits of their lower cost must be balanced with their often lower activity and/or durability performances. Durability is especially a challenge, with the general tendency of M-N4 single metal atom sites to dynamically transform or to degrade as a result of exposure to highly oxidative or reductive conditions. [ 3-4] The presentation will discuss these broad aspects, fundamentally related to the nature of the M-Nx active sites and their achievable active site density.

References

[1] X. Yang, A. Wang, B. Qiao, J. Li, J. Liu, T. Zhang, " Single-atom catalysts: a new frontier in heterogeneous catalysis ", Acc. Chem. Res, vol. 46, 2013, p. 1740-1748.

[2] Q. Zhang, J. Guan, " Single-atom catalysts for electrocatalytic applications ", Adv Funct. Mater. vol. 30, no. 31, 2020.

[3] K. Kumar, L. Dubau, F. Jaouen, F. Maillard, " Review on the Degradation Mechanisms of Metal-N-C Catalysts for the Oxygen Reduction Reaction in Acid Electrolyte: Current Understanding and Mitigation Approaches ", Chem. Rev. vol. 123, no. 15, 2023, pp. 9265-9326.

[4] D. Karapinar, N. Tran Huan, N. Ranjbar Sahraie, J. Li, D. Wakerley, N. Touati, S. Zanna, D. Taverna, L. H. G. Tizei, A. Zitolo, F. Jaouen, M. Fontecave, " Electroreduction ofCO2 on Single-Site Copper-Nitrogen-Doped Carbon Material: Selective Formation of Ethanol and Reversible Restructuration of the Metal Sites, Angew ", Chemie Int. Ed, vol. 58, no. 42, 2019, pp. 15098-15103.

Single iron atom sites on graphene