Insoluble Keggin‐Type P‐Mo‐V Polyoxometalates with <i>n</i> Bu ₄ N ⁺ Counterion: Recyclable Catalysts for 5‐Hydroxymethylfurfural Oxidation

Abstract Mixed n Bu 4 N + ‐substituted phosphomolybdovanadates of ( n Bu 4 N) 2.5+ x H 0.5 PMo 12‐ x V x O 40 ( x = 1–4) gross composition have been prepared by a promising ecological method and investigated as catalysts for the transformation of 5‐hydroxymethylfurfural. It has been shown that activation of vanadium(V) atoms in V 2 O 5 using the H 2 O 2 ‐affected approach followed by their insertion into a Mo‐containing framework provides a waste‐free synthesis of mixed heteropoly anions. The resulting solids have been characterized by XRD, IR, ICP‐AES, N 2 adsorption–desorption, and TGA methods to estimate their structural and textural characteristics. The catalysts exhibit significant activity and good reusability (at least five times) in the oxidation of a biomass‐derived precursor to produce 2,5‐diformylfuran in yield above 90%.