Metal Doping Activation of Anion-Mediated Electron Transfer in Catalytic Reactions

Abstract

Heteroatom-doping has emerged as a transformative approach to producing high-performance catalysts, yet the current trial-and-error approach to optimize these materials remains ineffective. To enable the rational design of more efficient catalysts, models grounded in a deeper understanding of catalytic mechanisms are essential. Existing models, such as <i>d</i>-band center theory, fall short in explaining the role of dopants, particularly when these dopants do not directly interact with reactants. In this study, we synthesize various heteroatom-doped catalysts to explore the correlation between the electronic effects of the dopants and catalyst activity. Using Co-MoS₂ as a model catalyst and the Li-S redox reaction within the cathode of Li-S batteries as a test system, we show the interaction between cobalt sites and adjacent lattice sulfur atoms disrupts the intrinsic structural and electronic symmetry of MoS₂. This disruption enhances the transfer of spin-polarized electrons from metal centers to lattice sulfur and promotes the adsorption of reactant intermediates. Furthermore, by analyzing 20 different dopant elements, we establish a linear relationship between the electron density in the lattice sulfur and catalyst activity toward the reduction of sulfur species, a relationship that extends to other catalytic systems, such as the hydrogen evolution reaction.