Mo-V-P-Ce/KCsWPAV composite catalysts for enhanced one-step oxidation of isobutene to methacrylic acid

•A novel two-component composite catalyst was prepared for the one-step oxidation of isobutene to methacrylic acid.•Ce addition increases the oxidizing capacity of reactive Mo species and promotes oxygen activation to form lattice oxygen, thus regulates the catalytic redox ability and oxygen mobility.•The incorporation of KCsWPAV heteropolyacids improves the acidity of Mo-V-P-Ce mixed oxides.•Under the combined effect of lattice oxygen and moderately acid, the selectivity of MAA is improved to 70 %. The direct synthesis of methyl methacrylate from isobutene is of great importance in the chemical industry. The direct oxidation of isobutylene to methacrylic acid is one of the key steps, but the selectivity of methacrylic acid is low in the products of one-step oxidation of isobutylene. The efficient one-step oxidation of isobutylene to methacrylic acid was achieved by preparing a Mo-V-P-Ce/KCsWPAV two-component composite catalyst combining asymmetric lattice oxygen with appropriate acidic heteropolyacid catalysts. The catalyst was characterized using XRD, FT-IR, BET, SEM, and others to analyze its structural properties, dimensional characteristics, and more. Results indicated that the composite catalyst accelerated the crystallization rate, with Ce enhancing the oxidation of the active molybdenum species and promoting oxygen activation to form lattice oxygen, thereby improving the oxidation of isobutylene. The heteropoly acids increased the percentage of medium strong acidic sites, enhancing the selectivity of methacrylic acid. Under optimized conditions, with an atmosphere to isobutylene molar feed ratio of ≥25:1 and a temperature of 400 °C, the Mo-V-P-Ce/KCsWPAV catalyst achieved a remarkable 91 % conversion of isobutylene with a 70 % selectivity towards methacrylic acid. The catalyst shows promise for practical applications in the one-step oxidation of isobutylene to produce methacrylic acid, providing a suitable solution to the problem of isobutylene overcapacity. [Display omitted]