Hydrogenation Reaction\nMechanisms on Ni-Doped MoS<sub>2</sub> Catalysts: A Density Functional\nTheory Study of Sulfur Edge\nEngineering and Coregulated Electronic Effects

Precise modulation of local interatomic interactions\naffecting\nthe electronic structure is an important method to control the catalytic\nactivity and reaction pathways. In this study, we focused on the hydrogenation\nreaction of naphthalene and employed density functional theory calculations\nto investigate the specific influence of electronic effects triggered\nby the coregulation of Ni and sulfur edge engineering on the hydrogenation\nperformance of Ni-doped MoS<sub>2</sub> at different edge sulfur coverages\n(Ni-MoS<sub>2</sub>-X-θ<sub>s</sub>). Our findings reveal that\nthe interaction between Ni and S in the catalyst matrix material modifies\nthe local electronic structure surrounding the sulfur atoms in the\nactive site. Notably, Ni doping facilitates significant electron transfer,\naltering the charge and the electronic states at the catalyst edge.\nThis, in turn, affects the adsorption capacity and reactivity of the\ncatalyst, thereby reducing the energy barrier of the hydrogenation\nreaction. Furthermore, we paid particular attention to the modulation\nof catalytic activity and reaction pathways under the Eley–Rideal\n(E-R) mechanism. Interestingly, the sulfur coverage exhibited a nonlinear\nrelationship with the adsorption and activation properties of the\nprobe molecule. Typically, changes in the Mo edge sulfur coverage\nprobability of Ni-MoS<sub>2</sub>-X-θ<sub>s</sub> have a greater\nimpact on the activation properties. Through comprehensive studies,\nwe demonstrated that both compositional and structural factors must\nbe considered when tailoring the catalytic performance. Importantly,\nadjusting the ratio of marginal sulfur atoms to metal atoms to 1:1\ncan effectively enhance the catalytic activity. This study provides\nvaluable insights into the electronic effects regulating the hydrogenation\nreaction activity of MoS<sub>2</sub>-based catalysts. It also opens\nthe way for the rational design of novel hydrogenation catalysts,\noffering a new strategy for optimizing the catalytic performance.