Tiede, D.M.; Utschig, L.M.

J. Am. Chem. Soc. 2013, 135, 13246-13249, 10.1021/ja405277g

The direct conversion of sunlight into fuel is a promising means for the production of storable renewable energy. Herein, we use Nature’s specialized photosynthetic machinery found in the Photosystem I (PSI) protein to drive solar fuel production from a nickel diphosphine molecular catalyst. Upon exposure to visible light, a self-assembled PSI-[Ni(P2PhN2Ph)2](BF4)2 hybrid generates H2 at a rate 2 orders of magnitude greater than rates reported for photosensitizer/[Ni(P2PhN2Ph)2](BF4)2 systems. The protein environment enables photocatalysis at pH 6.3 in completely aqueous conditions. In addition, we have developed a strategy for incorporating the Ni molecular catalyst with the native acceptor protein of PSI, flavodoxin. Photocatalysis experiments with this modified flavodoxin demonstrate a new mechanism for biohybrid creation that involves protein-directed delivery of a molecular catalyst to the reducing side of Photosystem I for light-driven catalysis. This work further establishes strategies for constructing functional, inexpensive, earth-abundant solar fuel-producing PSI hybrids that use light to rapidly produce hydrogen directly from water.

Gray, H.B.; Imperiali, B.

J. Am. Chem. Soc. 1993, 115, 8455-8456, 10.1021/ja00071a068

n/a

Bren, K.L.

Inorg. Chem. 2016, 55, 467-477, 10.1021/acs.inorgchem.5b02054

There has been great interest in the development of stable, inexpensive, efficient catalysts capable of reducing aqueous protons to hydrogen (H2), an alternative to fossil fuels. While synthetic H2 evolution catalysts have been in development for decades, recently there has been great progress in engineering biomolecular catalysts and assemblies of synthetic catalysts and biomolecules. In this Forum Article, progress in engineering proteins to catalyze H2 evolution from water is discussed. The artificial enzymes described include assemblies of synthetic catalysts and photosynthetic proteins, proteins with cofactors replaced with synthetic catalysts, and derivatives of electron-transfer proteins. In addition, a new catalyst consisting of a thermophilic cobalt-substituted cytochrome c is reported. As an electrocatalyst, the cobalt cytochrome shows nearly quantitative Faradaic efficiency and excellent longevity with a turnover number of >270000.