3D-printed metal-organic framework encapsulated Keggin heteropolyacid for catalytic purpose

Abstract

To address the limitations of metal-organic frameworks for large-scale applications and the challenges associated with the heterogenization of heteropolyacids, we developed a catalytic monolith leveraging the encapsulation concept and 3D-printing technology. In this approach, a Keggin-type heteropolyacid was encapsulated within a Fe-based metal-organic framework through an in-situ method and subsequently incorporated into a 3D printing ink for the fabrication of a catalytic monolith. The monolith underwent comprehensive characterization, elucidating its morphological, structural, and mechanical features. Moreover, the catalytic performance of the 3D-printed monolith was thoroughly evaluated in Knoevenagel condensation reaction, highlighting its remarkable catalytic activity and exceptional recyclability. Characterization of the recycled catalyst, along with a hot filtration test, further confirmed the stability of the catalyst, the suppression of heteropolyacid leaching, and the manifestation of true heterogeneous catalysis.