Accurate restricted transition-state shape selective hydrogenation of furfural over zeolite confined Cu catalyst

Transition-state shape selectivity plays a crucial role in catalytic systems where reactants and products exhibit comparable molecular dimensions, as it restricts the accessible configuration space of reaction intermediates. Herein, we designed a Cu@MFI catalyst by encapsulating Cu active sites within the well-defined micropores of MFI zeolite through a pore confinement strategy. This architecture preserves the zeolite framework integrity while maintaining unhindered internal mass transport, thereby enabling precise spatial control over transition-state configurations. Employing furfural hydrogenation as a probe reaction, the metal-zeolite synergy in Cu@MFI endowed the catalyst with exceptional activity (100% furfural conversion) and quantitative selectivity (100% furfuryl alcohol) at 70 °C, sustained across a broad temperature window. Mechanistic studies reveal that the transition-state shape selectivity effectively prevented H 2 O interaction with the furan ring, offering valuable insights for other reaction systems seeking to exploit shape selectivity for specific transformations. Cu@MFI catalyst spatially confines Cu in zeolite micropores, enforcing transition-state selectivity. This achieves 100% furfural-to-furanol conversion at 70 °C with suppressed H 2 O interference, while preserving framework integrity and mass transport.