CsCu0.1H2.9PMo11VO40 catalyst synthesized via a high shear mixer facilitated precipitation method for selective oxidation of methacrolein to methacrylic acid

Abstract

CsCu_0.1H_2.9PMo₁₁VO₄₀ (CsCuHPAV) with Keggin structure was successfully produced via a high-shear mixer (HSM)-facilitated precipitation method and used as a catalyst for the selective catalytic oxidation of methacrolein (MAL) to methacrylic acid (MAA) in this work. The structure and morphological characteristics of the as-obtained catalyst were analyzed by XRD, TG/DSC, FT-IR, Raman and UV-vis spectroscopy, SEM, BET, NH₃-TPD, XPS and so on. The results show that the HSM effectively intensified the micromixing during the process of CsCuHPAV precipitation, which provided high and uniform supersaturation for crystal nucleation and growth, and finally produced small CsCuHPAV particles with a narrow size distribution. A small catalyst with a high surface area resulted in the exposure of more acidic and active sites, which is helpful for the migration of V from the Keggin unit and the improvement of the catalytic performance. Consequently, the CsCuHPAV catalyst synthesized via the HSM achieved superior MAL conversion of 86.2%, MAA selectivity of 84.8%, and catalytic stability. This work provides a new and convenient preparation strategy for HPAV catalysts.