Thermal behavior of solid acids in the Rb3H(SO4)2-RbHSO4 system under ambient atmosphere


  • Chatr Panithipongwut KOWALSKI Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
  • Permpoon CHAIJAROEN Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
  • Farook KAEWNIYOM Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand


Solid acids, Rb3H(SO4)2, RbHSO4, Rb5H(SO4)4, Phase transition


The thermal behavior of solid acids in the Rb3H(SO4)2-RbHSO4 system under ambient atmosphere has been studied in comparison to the previously reported high-temperature behavior of the same system under humidified atmosphere. The findings showed that, under this level of humidity, the transition of RbHSO4, the transition of Rb5H3(SO4)4, and the disproportionation of Rb3H(SO4)2, occurred at the same temperatures as those under humidified atmosphere. However, the results from differential scanning calorimetry did not reveal the reaction temperature between Rb3H(SO4)2 and RbHSO4 due to the slow process. The dehydration temperatures of Rb5H3(SO4)4 were surprisingly similar between the systems under low and high humidity levels, while the dehydration of RbHSO4 under low humidity occurred at a lower temperature than that previously reported. Additionally, the findings suggested that the humidity levels played some roles in the kinetics of the reaction between Rb3H(SO4)2 and RbHSO4 which should be further studied.


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How to Cite

C. P. KOWALSKI, P. CHAIJAROEN, and F. KAEWNIYOM, “Thermal behavior of solid acids in the Rb3H(SO4)2-RbHSO4 system under ambient atmosphere”, J. Met. Mater. Miner., vol. 31, no. 1, Mar. 2021.



Original Research Articles