In situ synthesis of MoS2 catalysts from directly loaded molybdenum salt for more efficient co‑hydrogenation of coal and petroleum residue

MoS 2 demonstrates strong catalytic potential for the co‑hydrogenation of coal and petroleum residue (CHCPR) because of its excellent hydrogenation activity; however, its high cost limits practical application. To address this, a technical route was developed herein for catalysing the CHCPR using single-layer-dominant active MoS 2 generated in situ from ammonium molybdate directly loaded onto coal (MoDLRC). The mechanism and influencing factors governing in situ MoS 2 formation from MoDLRC were investigated. Furthermore, the catalytic performance of MoDLRC in the CHCPR was evaluated and compared with that of Fe-based catalysts. The results revealed that in tetralin solvent, higher temperatures (>400 °C) and higher initial hydrogen pressure favoured the reaction of ammonium molybdate with H 2 and S, promoted the rapid reduction of Mo 6+ to Mo 4+ and accelerated in situ MoS 2 formation while reducing intermediate accumulation. Under the CHCPR conditions involving a temperature of 400 °C, an initial hydrogen pressure of 7 MPa, a reaction time of 1 h and a sulphur/molybdenum molar ratio of 2, impregnation of an ammonium molybdate solution onto coal powder generated active MoS 2 in situ with a single-layer-dominant structure and particle size of 4–11 nm. Because this structure exposed additional active sites, it exhibited strong catalytic performance. The oil yield reached 81.35%, representing increases of 19.57% and 30.27% relative to FeOOH and Fe 2 O 3 , respectively, whereas the residue rate decreased to 2.84%. CH 4 and CO 2 generation was also suppressed, thereby improving hydrogen utilisation efficiency. Overall, the MoDLRC route for the CHCPR is simple, efficient and cost-effective and provides theoretical support and practical guidance for CHCPR optimisation.