Polyoxometalate as an Effective Catalyst for Catalytic Lignin into Value‐Added Molecules

Abstract Lignin, an inherently heterogeneous arylpropanoid polymer, presents a unique resource for the sustainable manufacture of aromatic chemicals and fuels. Recently, numerous catalytic strategies for lignin valorization have been explored. Polyoxometalates (POMs), with their distinctive structures enabling control of redox processes in lignin conversion, have been of particular interest. However, a comprehensive assessment of this emerging field of study is currently missing. This paper aims to fill this gap with a detailed review of the use of POMs for catalytic lignin conversion into value‐added compounds. This review delves into various catalytic lignin conversion techniques, including thermal catalysis, electrocatalysis, and tandem processes for lignin separation, depolymerization, and upgrading. Moreover, we highlight innovative investigations utilizing polyoxometalate‐ionic liquids (POM‐ILs), POM‐deep eutectic solvents (POM‐DESs), and solidification or immobilization techniques for POMs as lignin valorization catalysts. Lastly, we discuss the future prospects and challenges in the domain of POM catalytic lignin conversion.