The Metal–Acid Synergy of a Bifunctional CoMoS/HY Catalyst for Selective Hydrocracking of C–C Bridging Bonds in Naomaohu Coal to Produce Arenes

Selective cleavage of stable C–C bridging bonds in the macromolecular framework of low-rank coal is crucial for its mild conversion to aromatics. Herein, a bifunctional CoMoS/HY catalyst, featuring highly dispersed CoMoS nanosheets anchored on ordered HY channels (3–4 nm), was successfully constructed for the selective hydrocracking of low-rank coal. Strong metal–support interactions stabilize surface Mo species and enrich weak acid sites. The weak Lewis acid sites are primarily responsible for driving the polarization and activation of C–C bridging bonds. Consequently, the incorporation of HY remarkably boosts intrinsic activity, giving outstanding turnover frequencies (TOF) of 85.4 h –1 for Mo and 89.7 h –1 for acid sites (both three times higher than unsupported CoMoS). Under mild conditions (270 °C, 2 MPa H 2, 3 h), the catalyst achieved 98.70% diphenylmethane conversion with >96% selectivity for arenes. When applied to catalytic hydrocracking of residue from the thermal dissolution of Naomaohu coal, it produced a liquid oil yield of 37.2 wt %, which is more than five times higher than that of the noncatalytic hydrocracking, while also demonstrating deoxygenation and coke suppression capabilities. This work highlights a metal–acid-driven synergistic pathway for the efficient conversion of low-rank coal into high-value arenes.