Towards scalable reductive etherification of 5-hydroxymethyl-furfural through iridium-zeolite-based bifunctional catalysis

Developing practical and scalable catalytic approaches for directly converting concentrated 5-hydroxymethylfurfural (HMF) into value-added bio-based chemicals represents a major challenge in efforts to make the lignocellulosic biorefinery a sustainable and ecologically viable reality. We present here Ir/Na-ZSM-5 as a robust catalyst for efficiently producing 2,5-bis(methoxymethyl)furan (BMMF), a crucial compound for advanced biorefineries, through the reductive etherification of HMF. Benefitting from its unique structural features as well as the cooperative interaction between selective hydrogenation enabled by ultrasmall Ir nanoparticles and appropriate surface acidity resulting from alkali exchange, Ir/Na-ZSM-5 achieves impressive BMMF yields (91%) and maintains over 98% carbon balance from concentrated HMF (up to 22.6 wt%) under mild conditions (50 °C, 1 MPa H 2 ). Moreover, the catalyst displays outstanding stability with an unmatched turnover number during extended flow-reaction processes, underscoring its applicability for large-scale production. Ir/Na-ZSM-5, featuring ultra-small Ir NPs and suitable surface acidity resulted from alkali exchange, could deliver impressive BMMF yields from concentrated HMF (up to 22.6 wt%) via reductive etherification under mild conditions (50 °C, 1 MPa H 2 ).