CO mediated structural engineering coupled with Cu/Co bimetallic doping for enhanced hydrodesulfurization performance

This study demonstrates an effective strategy for modulating the basal plane activity of Cu_0.1Co_1.9MoS₂-C catalysts through CO molecule-mediated structural engineering coupled with Cu/Co bimetallic synergistic doping. Experimental results reveal that this approach not only significantly enhances sulfur vacancy (S_V) concentration and 1 T phase proportion (70 %) in MoS₂ basal planes, but also improves thiophene hydrodesulfurization (HDS) activity to 96 %, with a 2.6-fold increase in reaction rate constant compared to conventional CoMoS₂ catalysts (0.21 → 0.08 h^-1). Theoretical calculations, including ab initio molecular dynamics (AIMD) and density functional theory (DFT), elucidate that the bimetallic doping of Cu and Co facilitates sulfur removal under CO mediation (∆G = 0.017 and 0.015 eV), while substantially reducing the energy barriers for H₂ dissociation (∆E = 1.47 → 1.14 eV) and S_V formation (∆E = 2.32 → 0.98 eV). Microkinetic analysis further unravels that the hydrogenation pathway (HYD) predominates due to its lower activation energy in the rate-determining step (1.11 eV) and higher steady-state reaction rate (2.01 ×10¹ s^-1) relative to that of direct desulfurization (DDS) route. This work provides new theoretical insights and technical approaches for designing high-performance MoS₂-based HDS catalysts.