Effect of Cobalt(II) on Acid-Modified Attapulgite-Supported Catalysts on the Depolymerization of Alkali Lignin

With an aromatic structure, lignin has great potential for the production of high value-added chemicals. In this study, Co/m-ATP catalyst was prepared by the co-impregnation method to depolymerize lignin with inexpensive attapulgite as a carrier, 1,4-dioxane as a solvent, and ethanol as an in situ hydrogen source. Meanwhile, formaldehyde stabilization facilitates lignin monomer production during biomass depolymerization. The effects of Co particle loading and reaction conditions (e.g., temperature and reaction time) on lignin conversion and product yield were investigated, resulting in a low char yield (6.6 wt %) and high bio-oil yield (63.1 wt %) when alkali lignin was depolymerized over the Co/m-ATP catalyst (cobalt loading of 15 wt %) at 220 °C for 8 h. Therefore, this catalyst with the advantage of low cost and high catalytic activity would be a potential catalyst during the depolymerization of lignin.