Electrocatalytic Reduction of CO₂ into Formate with Glassy Carbon Modified by [Fe₄N(CO)₁₁(PPh₂Ph-linker)]⁻

Abstract

Immobilization of molecular electrocatalysts with retention of catalytic activity is necessary if they will be incorporated into functional photoelectrochemical devices. Most often, immobilization diminishes catalytic performance. Glassy-carbon electrodes covalently modified with [Fe 4 N(CO) 12 ] − are active for electrocatalytic formate production from CO 2 at −1.2 V vs SCE in aqueous solutions buffered at pH 5−9. The modified electrodes are stable for at least 4 days, as demonstrated using cyclic voltammetry experiments. Electrode modification was performed via cycloaddition of alkyne-functionalized [Fe 4 N(CO) 12 ] − with azide-modified glassy-carbon electrodes.

Design of robust 2,2′-bipyridine ligand linkers for the stable immobilization of molecular catalysts on silicon(111) surfaces

“…In homogeneous catalysis, the hydride is generated by stepwise electron transfer and coupled proton transfer steps, whereas for the linker-tuned system catalysis occurs via a concerted electron/proton transfer step. 24 An interesting extension of this work would be to examine how the bound (Cp*H)Rh moiety affects the band structure of the electrode, as has been recently investigated by Rose and coworkers. 80 In summary, the detachment of bipyridine-based moieties from Si(111) was assessed with the goal of identifying covalentlybound systems with improved robustness under operating conditions.…”

“…The catalyst was stable for at least 1000 electrochemical cycles and showed a turnover frequency (TOF) of 0.8 s À1 for reduction of CO 2 to CO. 23 In related work, Fe 4 N clusters have been attached to glassy carbon electrodes using similar click reactions, yielding stability for 4100 h and improved turnover numbers relative to the homogeneous system. 24 Other carbon-bound catalyst systems include Co and Ni 25,26 catalysts grafted onto glassy carbon surfaces, as well as Rh and Co 27,28 catalysts bound to graphite. Ni(P 2 N 2 ) 2 hydrogen-evolution catalysts have also been bound to glassy carbon electrodes, although due to Ni-P bond cleavage the catalysts decompose in acidic acetonitrile.…”

Enabling storage and utilization of low-carbon electricity: power to formic acid

“…47c). 304 Indeed, during the CPE experiment with the modified electrode, no degradation was observed for at least 4 days. An FE of 75 ± 20% and a TON of 52500 were achieved at −1.25 V vs. SCE in a pH 9 buffer.…”

“…Schematics of various catalysts immobilized modified electrode surfaces reported for electrochemical reduction of CO2 to FA: (a) GE-(MWCNT/CoTAPc)n; 302 (b) pyrene functionalized Mn-modified CNT; 303 (c) alkyne-terminated [Fe4N(CO)12]on azide functionalized GC; 304 (d) PEI-NCNT/GC. 307 (e) Proposed formate formation mechanism at 4-PEM-Modified Au electrode.…”

Übergangsmetallkomplexe als Katalysatoren für die elektrische Umwandlung von CO2 – eine metallorganische Perspektive

“…Durch Alkinylfunktionalisierung und anschließende Cycloaddition an den azidterminierten glasartigen Kohlenstoff konnten die Autoren den Katalysator in Form von Triazolfunktionen kovalent an die Elektrode binden. Auch wenn die Faraday‐Effizienz von >95 % auf 75±20 % abnimmt, kompensiert eine Erhöhung der Katalysatorstabilität von mehr als drei Tagen den Selektivitätsverlust [182e] …”