ContinuousTransfer Hydrogenolysis of Diphenyl EtherUsing 2‑Propanol and Ni Catalyst-Fixed Bed Reactor

Continuous liquid-phase transfer hydrogenolysis of diphenyl ether (DPE), a lignin model compound, was carried out utilizing 2-propanol (IPA) as a hydrogen-donating solvent and a Ni catalyst-fixed bed reactor. Approximately 90% conversion of DPE and the corresponding formation of monomeric products (benzene, phenol, cyclohexane, and cyclohexanol) were observed without short-term catalyst deactivation under the following conditions: 160 °C, 0.10 M DPE in IPA, 4.4 min average catalyst contact time, and 6.0 MPa system pressure. Further analysis showed that the continuous reaction system was capable of suppressing undesired subreactions such as H₂ gas formation and phenol hydrogenation, while catalyst regeneration was also possible under certain conditions.