Design and Synthesis of Brønsted‐Lewis Acidic Imidazole‐Based Poly(ionic Liquid)s for Efficient Conversion of Corn Stover to 5‐Hydroxymethylfurfural

The direct and efficient catalytic conversion of lignocellulosic biomass into high‐value platform chemicals is a pivotal challenge for sustainable biorefining. A Brønsted‐Lewis double‐acidic imidazole‐based poly(ionic liquid)s catalyst P([VIM‐PS][AlCl ₄ ]‐[DVIM][Br ₂ ]) was designed and synthesized by copolymerization reaction using a quaternary ammonium salt of vinylimidazole ([VIM‐PS][AlCl ₄ ]) functionalized with a sulfonic acid group and quaternized with AlCl ₃ as a monomer and bis‐imidazolium ([DVIM][Br ₂ ]) as a crosslinking agent. This solid catalyst demonstrated exceptional performance in the one‐pot conversion of raw corn stover into 5‐hydroxymethylfurfural (HMF), achieving a high biomass conversion of 86.1% and a remarkable HMF yield of 43.5%, accompanied by a furfural yield of 28.8% from the hemicellulose fraction. Notably, the process exhibited excellent scalability, with the conversion and HMF yield remaining at 85.1% and 42.6%, respectively, upon a 30‐fold scale‐up. The catalyst also displayed broad applicability to various biomass feedstocks. Moreover, it could be reused for at least six cycles without significant loss of activity, underscoring its robustness. A comprehensive green chemistry metrics analysis highlighted the sustainability of the process, emphasizing the crucial roles of catalyst recyclability and solvent recovery in minimizing waste. This work presents a green, efficient, and scalable catalytic strategy for the integrated valorization of lignocellulosic biomass into valuable furanic compounds.