Hydrogen produced from hydrohalic acid solutions by a two-electron mixed-valence photocatalyst.
Energy conversion cycles are aimed at driving unfavorable, small-molecule activation reactions with a photon harnessed by a transition metal complex. A challenge that has occupied researchers for several decades is to create molecular photocatalysts to promote the production of hydrogen from homogeneous solution. We now report the use of a two-electron mixed-valence dirhodium compound to photocatalyze the reduction of hydrohalic acid to hydrogen. In this cycle, photons break two RhII-X bonds of a LRh0-RhIIX2 core in the presence of a halogen trap to regenerate the active LRh0-Rh0 catalyst, which reacts with hydrohalic acid to produce hydrogen.
Heyduk
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Department of Chemistry, 6-335, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA.
Nocera
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