Co(II) exchange into zeolites A and X from formamide solution depends upon water content

Ion exchange of Co(II) for Na+ was attempted at 23 degrees C for zeolites A and X using solvents which ranged in composition from pure water to incompletely dried formamide. The results show that the extent of ion exchange is approximately proportional to the water content for [H2O] < 1.5 M, apparently extrapolating to zero at zero water content. Small amounts of water in formamide disproportionately increase the extent of ion exchange, and small amounts of formamide in water disproportionately hinder ion exchange. No pure organic solvent has yet been found which is suitable for ion exchange into zeolites. (C) Elsevier Science Inc. 1996