A modified heteropoly acid catalyst with cetyltrimethylammonium bromide for methacrolein to methacrylic acid

[Display omitted] •The CTA-CsPAV catalyst for oxidation of methacrolein to methacrylic acid was prepared by the emulsion method.•The effects of CTAB on CTA-CsPAV catalyst were studied.•The selectivity to MAA over CTA-CsPAV (95%) was higher than that of CsPAV (69%) at the same MAL conversion level (65%). A novel type of heteropolyacids, CTAB-CsH3PMo11VO40 (CTA-CsPAV), was developed by a method of emulsion synthesis using cetyltrimethyl ammonium bromide (CTAB) as the structure promoter, which was applied as a catalyst in the oxidation of methacrolein (MAL) to methacrylic acid (MAA) with fixed-bed reactor. The structure and property of CTA-CsPAV were characterized by FT-IR, XRD, nitrogen adsorption-desorption, NH3-TPD, SEM, XPS, and so on. The structure-performance relationship of CTA-CsPAV was systematically studied, wherein the influence of surface area, acidity, redox property of CTA-CsPAV were focused and discussed. Importantly, the long-term performance of CTA-CsPAV was also investigated.