Fabrication of a Single-Atom Mo catalyst for significantly enhanced hydrodesulfurization activity of dibenzothiophene

• Atomically dispersed 5Mo@NC catalysts prepared by the self-polymerization-adsorption-pyrolysis method. • Mo in 5Mo@NC exists in a MoN3S1 tetra-coordinated structure. • The MoN3S1 structure weakened the C-S bond of DBT and promoted the DDS pathway of the HDS reaction. • 5Mo@NC exhibits extremely high TOF values and DDS selectivity in the HDS reaction of DBT. The design and development of ultra-high performance catalysts are crucial for upgrading the existing hydrodesulfurization (HDS) process. In this study, atomically dispersed Mo species catalyst was prepared using a self-polymerization-adsorption-pyrolysis strategy. The obtained catalyst exhibited significantly higher turnover frequency (TOF) values compared to that of the catalyst prepared by conventional method, and demonstrated superior hydrogenolysis selectivity in the HDS of dibenzothiophene (DBT). XANES and EXAFS results revealed that the single-atom Mo adopted a tetra-coordinated structure, Mo-N 3 S 1 . DFT calculations indicated a significant electron transfer between the DBT molecule and the nMo@NC catalyst. This charge transfer was primarily concentrated between the sulfur atoms of DBT and the monoatomic molybdenum, which weakened the C-S bond and facilitated the direct hydrolysis desulfurization (DDS) reaction pathway for the HDS process, thereby reducing hydrogen consumption.