Vapour-phase condensation of methyl propionate with trioxane over alumina-supported potassium catalyst

Alumina-supported potassium (K/Al2O3) catalysts using pseudo-boehmite as the precursor were prepared by the impregnation/calcination method, characterised by XRD, SEM, ICP, N2 adsorption/desorption, CO2-TPD methods and TG analysis, and applied to the vapour-phase condensation of methyl propionate with trioxane to produce methyl methacrylate. The results showed the catalysts’ properties to be mainly affected by the calcined temperature (TC) and the crystal structure. The sample calcined at 1100°C exhibited the highest catalytic activity when mixed phases were formed and provided the appropriate specific surface area (SBET) and surface basic properties. The effects of TC, K-loading and reaction conditions on the catalytic performance were also investigated in a fixed-bed reactor. The yield of methyl methacrylate attained 29.2 % under the optimised conditions, and the deactivated catalyst could be completely regenerated by calcination.