Synergistic Catalysis of Composite Titanosilicate Zeolites for One-Step Ammoxidation of Acetone to 2-Nitropropane
摘要
The conventional nitration process, which relies on concentrated nitric acid as a reagent, presents significant challenges including high safety risks and substantial environmental burdens. To address these issues, this study developed a novel dual-base modified composite catalyst (TS-1@Ti-MWW-OH), which enables the efficient synthesis of 2-nitropropane via the ammoxidation/oxidation of acetone under mild conditions using ammonia and hydrogen peroxide. The core innovation of this work lies in the precise design of dual active sites with complementary functions, establishing a “synergistic relay” catalytic mechanism: the Ti4+ sites in Ti-MWW preferentially catalyze the conversion of acetone to acetone oxime, followed by the Ti4+ sites in TS-1 catalyzing the subsequent transformation of acetone oxime to 2-nitropropane. Through modification with 4-methoxypyridine/ethanolamine dual bases, the specific surface area and pore volume of the catalyst were significantly enhanced, thereby substantially improving reaction mass transfer efficiency and accessibility to active sites. Process simulation based on Aspen Plus V14 confirmed the potential for industrial scale-up of this route, achieving an annual production of 13000 tons of 2-nitropropane with a purity of no less than 99.99%, along with 760 tons of acetone oxime with a purity exceeding 99.8%. Furthermore, tray hydraulics analysis was employed to determine the main dimensions of key column equipment and their stable operating ranges within allowable flooding limits. This study, from the perspectives of both catalyst structural design and process engineering optimization, provides a promising new strategy for the green and sustainable production of nitroalkanes.
Graphical Abstract