Selective Oxidation of Methacrolein to Methacrylic Acid over Sb-Doped (NH 4 )H 3 PMo 11 VO 40

作者：Tianyu Guo, Lei Wang, Haitao Qian, Yuan Tian, Gang Wang, Jie Li, Chunshan Li · 发表于：Industrial & Engineering Chemistry Research · 年份：2025 · DOI：10.1021/acs.iecr.5c02100 · 被引用次数：3 · 研究领域：Polyoxometalates: Synthesis and Applications、Catalysis and Oxidation Reactions、Chemical Synthesis and Reactions

Selective oxidation of methacrolein (MAL) to methacrylic acid (MAA) is a pivotal step in the industrial production of methyl methacrylate (MMA). In this study, a series of Keggin-type ammonium phosphomolybdovanadate heteropoly acid (NH 4 HPAV) catalysts with modification of Sb component were systematically investigated for their catalytic performance in MAL partial oxidation to MAA. Comprehensive physicochemical characterizations including XRD, FT-IR, Raman spectroscopy, NH 3 -TPD, chemical titration, H 2 -TPR, and XPS were employed to elucidate the structural and functional impact of Sb incorporation. The results indicated that the introduced Sb partially substituted protons in the secondary structure, leading to a decrease of surface Bro̷nsted acid sites and significant modulation of the redox behavior of molybdenum species. In addition, the incorporation of Sb component would also improve the MAL adsorption and MAA desorption abilities on the catalyst surface. A strong linear relationship was observed between the MAL conversion and reduction capacity of the molybdenum species, highlighting the critical role of redox properties enhanced by Sb. The optimized Sb-modified catalyst exhibited a 23.6% increase in MAL conversion, compared to the unmodified catalyst while maintaining comparable MAA selectivity.