Tandemly coupled CO2 hydrogenation and carbonylation on SiO2-encapsulated Cu-ZnO nanoparticles with Ferrierite zeolite toward selective synthesis of oxygenates

Abstract

Tandemly coupled gas-phase CO2 hydrogenation reaction to dimethyl ether (DME) with its successive carbonylation (CO insertion) for one-step methyl acetate (MA) synthesis was investigated on newly designed SiO2-encapsulated Cu-ZnO nanoparticles (CZ@Si) hybridized with nano-sized Ferrierite (NFER) zeolite. The core-shell-structured CZ@Si with thermally stabilized Cu-ZnO nanoparticles having stronger Cu-O-Si interfaces was crucial to form an optimal CO/DME ratio, which was found to be a key step to switch the reaction pathway from methanol-mediate hydrocarbon formation route to carbonylation route to selectively synthesize oxygenates by CO2 hydrogenation-initiated tandemly coupled reaction. The formed methanol intermediate was further reacted to form DME by methanol dehydration, and the rates of surface methoxy formation and CO insertion to form acetyl intermediate were enhanced with the increased Brønsted acid sites in 8-membered ring channels on the NFER with higher MA selectivity of ∼50% through novel tandem reaction for efficient CO2 utilization. © 2024 Elsevier B.V.