CO2‐Enhanced Production and Synthesis of 2,5‐ Furandicarboxylic Acid under CO2 Flow through Henkel Reaction

Abstract The present study investigated the preparation of 2,5‐furandicarboxylic acid (FDCA) via the Henkel reaction between furoic acid alkali metal salts and zinc chloride under a continuous CO 2 flow at atmospheric pressure. The results obtained were compared with those of previous studies that used high‐pressure conditions or toxic cadmium catalysts. The pathways and rate‐determining steps of the reaction are revealed for the first time. Furthermore, the enhanced formation of FDCA through the promotion of carboxyl exchange and rearrangement during the reaction under a CO 2 flow was examined. The CO 2 ‐rich environment afforded a high FDCA yield of 86.30 %, which is the highest yield obtained to date using the Henkel reaction. The findings of this study offer economically improved conditions for large‐scale FDCA production.