A Low-Potential π-Extended Viologen Electron Donor Results in Increased H2 Production by CpI [FeFe]-Hydrogenase

Article Article scientifique Article A Low-Potential π-Extended Viologen Electron Donor Results in Increased H2 Production by CpI [FeFe]-Hydrogenase eng 2026-01-20 author Ostermann Nils 430159 Chimie analytique groupe 4 (CHIAL4) author Webb Sophie 0009-0001-9855-6546 972200 Chimie analytique groupe 4 (CHIAL4) author Do Nascimento Henriques Andrea 905130 Chimie analytique groupe 4 (CHIAL4) author Milton Ross Dean 0000-0002-2229-0243 930839 Services communs du dépt. de chimie minérale et analytique (CHIMO) 10.1021/acsorginorgau.5c00106 2694-247X https://pubs.acs.org/doi/10.1021/acsorginorgau.5c00106 [FeFe]-hydrogenases are known for their exceptional dihydrogen production activity, which opens a pathway to green hydrogen formation. To achieve the high turnover numbers found in natural environments, researchers aim to mimic biological electron donors using artificial electron delivery systems. In this sense, the use of an externally applied electrochemical potential is of particular interest, for which redox mediators often have to be included to effectively shuttle electrons between the electrode and the enzyme. The class of viologens, with methylviologen being the most prominent example, has been shown to perform efficient electron transfer. However, the reduced forms of such viologens are restricted in terms of stability and accessibility of the more reduced, low-potential species. Herein, we report the electrochemical and spectroscopic characterization of a viologen-based derivative, which is capable of storing two electrons at a low potential of −0.75 V vs. SHE. In combination with the [FeFe]-hydrogenase CpI, an activity of up to 10,480 μmolH2 mg–1CpI min–1 (molar activity of 11,179 μmolH2 μmol–1CpI s–1) could be achieved, which is 10 times greater than the commonly used dithionite-driven methylviologen assay under the same conditions. Hydrogen evolution reaction [FeFe]-hydrogenase Viologen CpI CrHydA1 Mediated electron transfer Dewey 540 Swiss National Science Foundation NCCR Catalysis (phase II) 225147 CH 40 Département de chimie minérale, analytique et appliquée 145 false https://doi.org/10.5281/zenodo.15688676 ACS Organic & Inorganic Au b8e067ea-91f0-49ce-993f-4a6eb9024d99 Article (Published version) Public acsorginorgau.5c00106.pdf 2470039 application/pdf CC BY-4.0 0566607a623607cc91baa09d258edc012e8b7f6e6f37a7a06b3555858303fe96 Vignette Public m_gg5c00106_0006.png 96830 image/png openAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie minérale, analytique et appliquée

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A Low-Potential π-Extended Viologen Electron Donor Results in Increased H₂ Production by CpI [FeFe]-Hydrogenase	ACS Organic & Inorganic Au			2026	5	2

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Do Nascimento Henriques, Andrea