Reversible hydrogen storage using CO 2 and a proton-switchable iridium catalyst in aqueous media under mild temperatures and pressures

Jonathan F. Hull, Yuichiro Himeda, Wan Hui Wang, Brian Hashiguchi, Roy Periana, David J. Szalda, James T. Muckerman, Etsuko Fujita

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Green plants convert CO 2 to sugar for energy storage via photosynthesis. We report a novel catalyst that uses CO 2 and hydrogen to store energy in formic acid. Using a homogeneous iridium catalyst with a proton-responsive ligand, we show the first reversible and recyclable hydrogen storage system that operates under mild conditions using CO 2, formate and formic acid. This system is energy-efficient and green because it operates near ambient conditions, uses water as a solvent, produces high-pressure CO-free hydrogen, and uses pH to control hydrogen production or consumption. The extraordinary and switchable catalytic activity is attributed to the multifunctional ligand, which acts as a proton-relay and strong π-donor, and is rationalized by theoretical and experimental studies.

Original languageEnglish
Pages (from-to)383-388
Number of pages6
JournalNature chemistry
Issue number5
Publication statusPublished - May 1 2012


ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)

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