Synthesis of Trioxane Using Heteropolyacids as Catalyst

Abstract

A high formaldehyde feed concentration and a low reaction temperature are among the advantages of using heteropolyacids (phosphotungstic acid and silicotungstic acid) as catalysts in the formation of trioxane; this cyclic trimer of formaldehyde (see scheme) is used in the industrial production of acetal resins. Compared to reactions with a conventional catalyst, like sulfuric acid, trioxane can be produced in higher yield and with higher selectivity.