Hydrogenation Reaction Mechanisms on Ni-Doped MoS2 Catalysts: A Density Functional Theory Study of Sulfur Edge Engineering and Coregulated Electronic Effects

Precise modulation of local interatomic interactions affecting the electronic structure is an important method to control the catalytic activity and reaction pathways. In this study, we focused on the hydrogenation reaction of naphthalene and employed density functional theory calculations to investigate the specific influence of electronic effects triggered by the coregulation of Ni and sulfur edge engineering on the hydrogenation performance of Ni-doped MoS₂ at different edge sulfur coverages (Ni-MoS₂-X-θ_s). Our findings reveal that the interaction between Ni and S in the catalyst matrix material modifies the local electronic structure surrounding the sulfur atoms in the active site. Notably, Ni doping facilitates significant electron transfer, altering the charge and the electronic states at the catalyst edge. This, in turn, affects the adsorption capacity and reactivity of the catalyst, thereby reducing the energy barrier of the hydrogenation reaction. Furthermore, we paid particular attention to the modulation of catalytic activity and reaction pathways under the Eley-Rideal (E-R) mechanism. Interestingly, the sulfur coverage exhibited a nonlinear relationship with the adsorption and activation properties of the probe molecule. Typically, changes in the Mo edge sulfur coverage probability of Ni-MoS₂-X-θ_s have a greater impact on the activation properties. Through comprehensive studies, we demonstrated that both compositional and structural factors must be considered when tailoring the catalytic performance. Importantly, adjusting the ratio of marginal sulfur atoms to metal atoms to 1:1 can effectively enhance the catalytic activity. This study provides valuable insights into the electronic effects regulating the hydrogenation reaction activity of MoS₂-based catalysts. It also opens the way for the rational design of novel hydrogenation catalysts, offering a new strategy for optimizing the catalytic performance.