A new catalyst mixture for synthesis of 1,3,5-trioxane

BACKGROUND A new catalyst mixture, namely trifluoromethanesulfonic acid + N-methylimidazolium trifluoromethanesulfonate (CF3SO3H + [mim][CF3SO3]), is developed to overcome long-standing problems of commercial catalysts and catalytic distillation for 1,3,5-trioxane synthesis. CF3SO3H serves as a catalyst to accelerate the main reaction and [mim][CF3SO3] serves as an extractive distillation agent to promote phase separation. Unlike the conventional design methods whose purpose is to increase catalytic activity and selectivity, this catalyst mixture is designed to significantly enhance phase separation. RESULTS Compared to commercial catalysts, the new catalyst mixture significantly increases product concentration in distillate, and significantly decreases byproduct concentration in reaction liquid phase and volatilization loss of reactant in reaction liquid phase. This catalyst mixture also considerably decreases corrosion rate and salting out effect of catalyst. CONCLUSIONS Our design approach is of general significance for catalytic distillation. As a real example, it is used to markedly improve the performances of commercial catalysts for 1,3,5-trioxane synthesis. (c) 2021 Society of Chemical Industry (SCI).