Decarboxylation of Lactones over Zn/ZSM‐5: Elucidation of the Structure of the Active Site and Molecular Interactions

Abstract

Herein, we report the catalytic decarboxylation of g-valerolactone (GVL) over Zn/ZSM-5 to butene,followed by aromatization at high yield with co-feeding of water.A n evaluation of the catalytic performance after prolonged periods of time showed that aw ater molecule is essential to maintain the decarboxylation and aromatization activities and avoid rapid catalyst deactivation. Synchrotron X-ray powder diffraction and Rietveld refinement were then used to elucidate the structures of adsorbed GVL and immobilized Zn species in combination with EXAFS and NMR spectroscopy. An ew route for the cooperative hydrolysis of GVL by framework Zn À OH and Brønsted acidic sites to butene and then to aromatic compounds has thus been demonstrated. The structures and fundamental pathwaysfor the nucleophilic attack of terminal ZnÀOH sites are comparable to those of Zn-containing enzymes in biological systems.