Tunable rhenium–ceria–zirconia catalysts for efficient deoxydehydration of C6 polyols: lattice engineering enables high muconate yield

Abstract

Sustainable routes to adipic acid from biomass-derived C₆ polyols typically rely on a two-step deoxydehydration (DODH)–hydrogenation sequence, of which the DODH step remains the primary barrier to industrial adoption. Here, we report a tunable rhenium catalyst supported on ceria–zirconia mixed oxides (Re/Ce_xZr_1−xO₂) engineered through precise control of metal-support interactions. Thermal diffusion of Zr⁴⁺ into CeO₂ nanorods induces lattice contraction and elevates the Ce³⁺ fraction, substantially enhancing the reducibility of surface rhenium species and accelerating the rate-determining step in Re-catalyzed DODH. Remarkably, up to 70 at% Zr can be incorporated without structural degradation, providing an unprecedented combination of oxygen mobility and rhenium redox synergy. The optimized Re/Ce_0.3Zr_0.7O₂ catalyst delivers trans, trans-muconate in 93% yield from galactarate using n-butanol, which functions simultaneously as solvent and green reductant.