A Pyrene-Triazacyclononane Anchor Affords High Operational Stability for CO2RR 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 CO2 reduction and a high stability of more than 6x10(6) TON when integrated on a gas-diffusion bioelectrode.