Efficient generation of H2 by splitting water with an isothermal redox cycle

Christopher L. Muhich, Brian W. Evanko, Kayla C. Weston, Paul Lichty, Xinhua Liang, Janna Martinek, Charles B. Musgrave, Alan W. Weimer

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190 Scopus citations


Solar thermal water-splitting (STWS) cycles have long been recognized as a desirable means of generating hydrogen gas (H2) from water and sunlight. Two-step, metal oxide-based STWS cycles generate H2 by sequential high-temperature reduction and water reoxidation of a metal oxide. The temperature swings between reduction and oxidation steps long thought necessary for STWS have stifled STWS's overall efficiency because of thermal and time losses that occur during the frequent heating and cooling of the metal oxide. We show that these temperature swings are unnecessary and that isothermal water splitting (ITWS) at 1350°C using the "hercynite cycle" exhibits H2 production capacity >3 and >12 times that of hercynite and ceria, respectively, per mass of active material when reduced at 1350°C and reoxidized at 1000°C.

Original languageEnglish (US)
Pages (from-to)540-542
Number of pages3
Issue number6145
StatePublished - Jan 1 2013
Externally publishedYes


ASJC Scopus subject areas

  • General

Cite this

Muhich, C. L., Evanko, B. W., Weston, K. C., Lichty, P., Liang, X., Martinek, J., Musgrave, C. B., & Weimer, A. W. (2013). Efficient generation of H2 by splitting water with an isothermal redox cycle. Science, 341(6145), 540-542. https://doi.org/10.1126/science.1239454