Can CO2 and steam react in the absence of electrolysis at high temperatures?

Song Zhou, Xue Yan, Cheng Liu, Binbin Qian, Jefferson Zhe Liu, Lian Zhang

Research output: Contribution to journalArticleResearchpeer-review


The fundamental question of whether CO2 can react with steam at high temperatures in the absence of electrolysis or high pressures is answered. These two gases are commonly co-present as industrial wastes. Herein, a simple experiment by flowing CO2 and steam through a CaCl2 matrix at 500–1000 °C and atmospheric pressure was designed. Comprehensive characterizations and density functional theory calculations were conducted. Meanwhile, this study aims to recover HCl from CaCl2 via a low-emission oxy-pyrohydrolysis process. As confirmed, CO2 and steam interact strongly on the CaCl2 surface, leading to an explicit formation of CaCO3/CaO and a nearly complete release of HCl. This is mainly contributed to a halved energy required for the splitting of H2O, resulting from the formation of a bicarbonate-like structure to replace Cl out of CaCl2, an otherwise industrial waste, whilst an important dopant for carbon capture, utilization and storage, and medium for electrochemical synthesis.

Original languageEnglish
Pages (from-to)6660-6667
Number of pages9
Issue number24
Publication statusPublished - 17 Dec 2020


  • CaCl
  • Halides
  • High-temperature chemistry
  • High-temperature reaction of steam and CO
  • Oxy-pyrohydrolysis

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