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Updated: Apr 6, 2026
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Unprecedentedly high formic acid dehydrogenation activity on an iridium complex with an N,N'-diimine ligand in water
Zhijun Wang1,2, Sheng-Mei Lu1, Jun Li1
1State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023 (China).
Abstract:
Hydrogen production from the dehydrogenation of formic acid (FA) is promising. Most of the current catalysts for FA dehydrogenation are effective only in the presence of bases or additives. We report here newly developed iridium complexes containing conjugated N,N'-diimine ligands for FA dehydrogenation in water without the addition of bases or additives. A turnover frequency (TOF) of 487 500 h(-1) with [Cp*Ir(L1)Cl]Cl (L1=2,2'-bi-2-imidazoline) at 90 °C and a turnover number (TON) of 2 400 000 with in situ prepared catalyst from [IrCp*Cl2 ]2 and 2,2'-bi-1,4,5,6-tetrahydropyrimidine (L2) at 80 °C were obtained, the highest values reported for FA dehydrogenation to date. A mechanistic study reveals that the formation of [Ir-H] intermediate species is the rate-determining step in the catalytic cycle.
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