Copper-based MOF-74 material as effective acid catalyst in Friedel Crafts acylation of anisole

Metal organic frameworks (MOFs) are emerging potential materials for catalytic applications. Among them, the honeycomb M2(dhtp) family, also known as MOF-74 or CPO-27 materials, are characterized by remarkable textural properties and accessible unsaturated metal sites (M). This work has been focused on the catalytic properties of novel Cu-MOF-74 material for the Friedel-Crafts acylation of anisole, as acid-catalyzed reaction test. The influence of reaction variables such as the type of acylating agent and solvent, and the reaction temperature have been studied. Additionally, the stability of Cu-MOF-74 was evaluated under different reaction conditions. Cu-MOF-74 achieved a remarkable catalytic performance in terms of anisole conversion and p-MAP yield. Additionally, the structural MOF-74 phase was preserved when using diluted concentrations of acetyl chloride as acylating agent. The relative acylating agent concentration was demonstrated to be crucial in the collapse of the crystalline MOF-74 phase. The catalytic activity of Cu-MOF-74, in terms of anisole conversion and selectivity to p-MAP product, was also superior to other Cu-containing MOF materials (HKUST-1) and conventional inorganic acid catalysts, such as aluminum-containing microporous zeolites (H-ZSM-5 and BETA) and mesoporous ordered materials (Al-MCM-41). Cu-MOF-74 also showed high stability and remarkable catalytic performance for seven consecutive reaction cycles when this MOF material was used in the best reaction conditions. (C) 2014 Elsevier B.V. All rights reserved.