抄録
Basic copper or magnesium carbonate was mixed with phosphoric acid in the mole ratio of P/M=2 (M; Cu or Mg). Each mixture was transformed to cyclo-tetraphosphate by heating. A part of the basic copper or magnesium carbonate was replaced with a rare earth oxide (La2O3, CeO2, Pr6O11, Nd2O3, Sm2O3, Yb2O3, and Y2O3) in this system. These mixtures containing one of the rare earth oxides were heated and then the products were analyzed by XRD, FT-IR, and TG-DTA. It was observed in copper system that the product changed from cyclo-tetraphosphate to pyrophosphate by the addition of rare earth oxide used in this study. In magnesium system, magnesium cyclo-tetraphosphate was formed in spite of the addition of rare earth oxide. Surface properties, specific surface area, acid strength and amount of acid sites, catalytic activity for dehydration of 2-propanol and cracking / dehydrogenation of cumene, were measured to clarify the role of rare earth element in magnesium cyclo-tetraphosphate.
