Synergy of Ru and NiAl-LDH for efficient selective hydrogenation of phenolic compounds under visible light

The Ru/NiAl-LDH catalyst was designed for the selective hydrogenation of phenolic compounds under visible light irradiation and mild conditions (55 °C, atmospheric H₂), and it achieved 99% conversion of phenol with 99% selectivity to cyclohexanol. XPS and DFT calculations confirmed that Ni 2+ in the NiAl-LDH support donates electrons to the Ru center, creating an electron-rich Ru site that enhances H 2 activation. In situ DRIFT studies verified that visible-light irradiation promotes the heterolytic dissociation and adsorption of H 2 on Ru active sites. Additionally, surface hydroxyl groups on the NiAl-LDH facilitate phenol adsorption and concentration near active sites. The catalyst demonstrated broad applicability to substituted phenolic compounds and excellent recyclability over multiple cycles. The synergistic effect between the electron-rich Ru sites and the hydroxyl groups on the NiAl-LDH surface ensures highly efficient photocatalytic hydrogenation of phenol to cyclohexanol.