A Pyrene-Triazacyclononane Anchor Affords High Operational Stability for CO 2 RR by a CNT-Supported Histidine-Tagged CODH.

An original 1-acetato-4-(1-pyrenyl)-1,4,7-triazacyclononane (AcPyTACN) was synthesized for the immobilization of a His-tagged recombinant CODH from Rhodospirillum rubrum (RrCODH) on carbon-nanotube electrodes. The strong binding of the enzyme at the Ni-AcPyTACN complex affords a high current density of 4.9 mA cm -2 towards electroenzymatic CO 2 reduction and a high stability of more than 6×10 6  TON when integrated on a gas-diffusion bioelectrode.