Efficient Hydrogen Storage and Production Using a Catalyst with an Imidazoline-Based, Proton-Responsive Ligand

Lin Wang, Naoya Onishi, Kazuhisa Murata, Takuji Hirose, James T. Muckerman, Etsuko Fujita, Yuichiro Himeda

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25 Citations (Scopus)


A series of new imidazoline-based iridium complexes has been developed for hydrogenation of CO2 and dehydrogenation of formic acid. One of the proton-responsive complexes bearing two −OH groups at ortho and para positions on a coordinating pyridine ring (3 b) can catalyze efficiently the chemical fixation of CO2 and release H2 under mild conditions in aqueous media without using organic additives/solvents. Notably, hydrogenation of CO2 can be efficiently carried out under CO2 and H2 at atmospheric pressure in basic water by 3 b, achieving a turnover frequency of 106 h−1 and a turnover number of 7280 at 25 °C, which are higher than ever reported. Moreover, highly efficient CO-free hydrogen production from formic acid in aqueous solution employing the same catalyst under mild conditions has been achieved, thus providing a promising potential H2-storage system in water.

Original languageEnglish
Pages (from-to)1071-1075
Number of pages5
Issue number6
Publication statusPublished - Jan 1 2017



  • CO hydrogenation
  • H storage
  • homogeneous catalysis
  • imidazoline
  • iridium complex

ASJC Scopus subject areas

  • Environmental Chemistry
  • Chemical Engineering(all)
  • Materials Science(all)
  • Energy(all)

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