High-efficiency and durable V–Ti–Nb ternary catalyst prepared by a wet-solid mechanochemical method for sustainably producing acrylic acid via acetic acid–formaldehyde condensation

Based on the precise phase control V species adjustment of vanadium phosphorus oxides (VPOs), a series of metal oxides (Nb(2)O(5), MoO(3), WO(3), and Bi(2)O(3)) were selected as modification agents to further enhance the catalytic activity and retain the excellent durability of VPO–TiO(2)-based catalysts for the new procedure of producing acrylic acid via acetic acid–formaldehyde condensation. At an elevated liquid hourly space velocity (LHSV), the (AA + MA) selectivity reached 92.3% with a (MA + AA) formation rate of 63.8 μmol(−1) g(cat)(−1) min(−1) over the Nb-decorated catalyst (catalyst VTi–Nb), and it maintained good durability for up to 100 h. The detailed characterization results of XRD, Raman, XPS, NH(3)-TPD, CO(2)-TPD, and H(2)-TPR, demonstrated that the addition of Nb(2)O(5) could observably enhance the catalytic efficiency of the VPO–TiO(2) catalyst. It not only improved the catalyst durability by enhancing prereduction of the V(5+) species, but also enhanced the active site density to improve the catalytic activity.