Mesoporous K-doped MoVTeNbOx Catalyze the Direct Oxidation of Propane to Acrylic Acid.

K-doped MoVTeNbOx were prepared rapidly and simply by spray drying method and applied to catalyze the selective oxidation of propane to acrylic acid. Results show that doping of K could affect the relative content of M1 and M2 phases in MoVTeNbOx. The as-prepared K-doped MoVTeNbOx exhibited a unique spherical structure agglomerated by needle particles. These needles shaped particles interlaced and stacked with each other to form a mesoporous structure with an average pore size range of 27.26 to 50.78 nm. Moreover, compared with undoped catalysts, doping of K increased the surface V5+ active sites content of the MoVTeNbOx from 60 to 75%. For the conversion of propane to acrylic acid, an appropriate amount of M2 increased the conversion of propane. The selectivity of K-doped MoVTeNbOx catalyst for acrylic acid was significantly improved, possibly due to the distinct reduction in the number of medium acid sites caused by the introduction of K. Furthermore, the special mesoporous structure formed boosted the adsorption and activation of the catalyst for propane and the diffusion of product, which is important to improve the catalytic performance of MoVTeNbOx. Under the optimal reaction condition, the maximum selectivity and yield of K-doped catalyst (K/Mo = 0.005) for acrylic acid reached 72.06% and 49.57%, respectively.Mesoporous K-doped MoVTeNbOx catalyze the direct oxidation of propane to acrylic acidGraphical Abstract: K-doped MoVTeNbOx were prepared rapidly and simply by spray drying method and applied to catalyze the selective oxidation of propane to acrylic acid. Results show that doping of K could affect the relative content of M1 and M2 phases in MoVTeNbOx. The as-prepared K-doped MoVTeNbOx exhibited a unique spherical structure agglomerated by needle particles. These needles shaped particles interlaced and stacked with each other to form a mesoporous structure with an average pore size range of 27.26 to 50.78 nm. Moreover, compared with undoped catalysts, doping of K increased the surface V5+ active sites content of the MoVTeNbOx from 60 to 75%. For the conversion of propane to acrylic acid, an appropriate amount of M2 increased the conversion of propane. The selectivity of K-doped MoVTeNbOx catalyst for acrylic acid was significantly improved, possibly due to the distinct reduction in the number of medium acid sites caused by the introduction of K. Furthermore, the special mesoporous structure formed boosted the adsorption and activation of the catalyst for propane and the diffusion of product, which is important to improve the catalytic performance of MoVTeNbOx. Under the optimal reaction condition, the maximum selectivity and yield of K-doped catalyst (K/Mo = 0.005) for acrylic acid reached 72.06% and 49.57%, respectively.Mesoporous K-doped MoVTeNbOx catalyze the direct oxidation of propane to acrylic acid [ABSTRACT FROM AUTHOR]