A Pyrene‐Triazacyclononane Anchor Affords High Operational Stability for CO₂RR by a CNT‐Supported Histidine‐Tagged CODH

Abstract

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 carbonnanotube electrodes. The strong binding of the enzyme at the Ni-AcPyTACN complex affords a high current density of 4.9 mA cm À 2 towards electroenzymatic CO 2 reduction and a high stability of more than 6 × 10 6 TON when integrated on a gas-diffusion bioelectrode.

Bioelectrocatalytic CO2 Reduction by Redox Polymer-Wired Carbon Monoxide Dehydrogenase Gas Diffusion Electrodes

“…Recent reports have shown the fabrication of highly active bioelectrodes for CO 2 reduction using a recombinant CODH from Rhodospirillum rubrum in direct electron transfer (DET) with carbon nanotube-modified electrode surfaces. 16,18 Although the current densities of these electrodes reached up to −4.9 mA cm −2 , 18 approaching the performance of metaland molecular-based catalysts, 16 the use of specific linkers for adequate enzyme immobilization was crucial for optimum performance. Under DET configuration, the enzymes must be in direct contact with the electrode and in an appropriate orientation to allow electrical wiring to the conductive surface.…”