Hydrogenolysis of guaiacol and lignin to phenols over Ni/ Nb2O5-HZSM-5 catalyst

Selective hydrogenolysis of CAr-O bonds in lignin to produce aromatic compounds typically necessitates severe conditions. We developed a Ni/Nb2O5-HZSM-5 catalyst that facilitates direct cleavage of guaiacol's aryl ether bonds at reduced temperatures (200 degrees C) and pressure (0.1 MPa H2), achieving a conversion of 89.5 % with the selectivity of phenol at 81.7 %, while retaining its activity after five cycles. The Ni/Nb2O5-HZSM-5 exhibits a higher yield of phenol (49.1 mmolphenol & sdot;gNi1 & sdot;h1), currently achieving the highest phenol yield among Ni-based catalysts. The addition of Nb2O5 enhances the dispersion of Ni and augments the effective surface area. In addition, the strong interaction of Nb with the HZSM-5 changed the electronic state of Nb and enhanced the resistance of the catalyst to high temperature and mechanical stress. Employing this catalyst for lignin depoly-merization in an aqueous medium led to a 17.0 wt% yield of alkyl phenolic compounds. This approach represents an advancement in biomass resource conversion, circumventing the dependency on high-pressure and precious- metal catalysts, and signaling a new trajectory for sustainable biomass utilization in scientific research