Enhancement of surface acidity and catalytic activity by glass formation of calcium metaphosphate

Effective acid sites for the dehydration of 2-propanol and isomerization of 1-butene were found to be generated by glass formation of calcium metaphosphate. The number of these sites with strong acidity remarkably decreased by the crystallization of the glass, where the condensation of hydroxyl groups were significant. Thus, the sites must be the monohydrogen phosphate protons.