Spontaneous generation of an atomically dispersed Mo and MoS2 coupling catalyst via reaction induction transformation for enhancing local hydrogen concentration in hydrogenation†

The development of a synergistic coupling catalyst at the atomic scale for slurry-phase hydrogenation of vacuum residue (VR) is extremely challenging. Herein, we designed and constructed a robust coupling catalyst comprising Mo single atoms and MoS₂ (Mo SAs–MoS₂) using a reaction induction transformation strategy. The spontaneous generation of Mo SAs–MoS₂ synergistically promoted H₂ activation and enhanced local active hydrogen concentration in the hydrogenation of VR. Benefiting from the strong hydrogen concentration distribution in MoS₂ and Mo SAs, the catalyst revealed remarkable hydrogenation performance toward VR with a TOF_T of up to 0.39 s⁻¹, liquid product yield of 92 wt%, and coke content of 0.6 wt%. Theoretical calculations revealed that the synergistic action of Mo SAs–MoS₂ facilitated electron transfer between Mo species and reactants, reducing the desorption energy barriers for H₂ and anthracene and thereby promoting the hydrogenation of VR. This work provides a novel idea for the design of efficient coupling catalysts for strengthening local active hydrogen concentration in the hydrogenation of VR, and this concept can be applied to other hydrogenation systems.