Production of potassium phosphotungstate

TLDR: In this article, solid potassium carbonate is added to an aqueous solution of phosphotungstic acid and both are brought into contact by stirring, and the resultant formed precipitates are then concentrated under reduced pressure to afford the objective of HXK3-XPW12O40 (X is about 0.5-2.8).

Abstract: PURPOSE:To advantageously produce potassium phosphotungstate capable of exhibiting high activity as an alkylating catalyst for aromatic compounds by bringing an aqueous solution of phosphotungstic acid into contact with solid potassium carbonate. CONSTITUTION:Solid potassium carbonate is added to an aqueous solution of phosphotungstic acid and both are brought into contact by stirring. In the process, the aforementioned aqueous solution preferably contains about 10-150g/100cc H3PW12O40. The aforementioned contact is preferably carried out at about 5-50 deg.C. The resultant formed precipitates are then concentrated under reduced pressure to afford the objective potassium phosphotungstate composed of HXK3-XPW12O40 (X is about 0.5-2.8). The obtained potassium phosphotungstate is subsequently used as a catalyst in alkylating aromatic compounds such as naphthalenes with an alkylating agent such as ethylene. The aforementioned potassium phosphotungstate is used in an amount of preferably about 0.0001-1 pt.wt. based on 1 pt.wt. aromatic compounds.