Toward economy hydrogenation: Highly efficient hydrodeoxygenation of guaiacol to cyclohexanol over a CoNi-NC catalyst

Abstract

Lignin and other underutilized biomass resources have significant potential for producing specific chemicals through hydrogenation. However, current challenges in this field include not only the high cost of catalyst preparation but also the demanding reaction conditions required. In this study, a CoNi-NC alloy catalyst with high specific surface area and mesoporous structure was prepared by calcining Ni-doped ZIF-67 material. The Co3Ni1-NC catalyst achieved complete conversion of guaiacol with a cyclohexanol yield reaching 92.7 %, under conditions of 1.2 MPa H2 pressure and 180 °C reaction temperature. The study found that Co-Ni alloys possess superior hydrogen adsorption activation capability, which is a critical factor affecting the hydrogenation capacity of the catalyst. The prepared Co3Ni1-NC not only significantly reduces the H2 pressure and temperature for the guaiacol hydrodeoxygenation (HDO) reaction but also achieves high-efficiency conversion of guaiacol in water as the primary solvent. This undoubtedly saves costs and reduces environmental impact. The CoNi-NC catalyst also possesses magnetic properties, making it easy to fully recover. Related characterization and cycling experiments have demonstrated that the catalyst has excellent recyclability. These properties of the CoNi-NC catalyst will significantly enhance its economic viability. Furthermore, this catalyst exhibited excellent hydrogenation performance for lignin model compounds, providing a valuable reference for the application of alloy MOFs materials in the hydrogenation of lignin compounds.