Anode Preparation Strategies for the Electrocatalytic Oxidation of Water Based on Strong Interactions between Multiwalled Carbon Nanotubes and Cationic Acetylammonium Pyrene Moieties in Aqueous Solutions. Issue 10 (6th October 2016)

• Record Type: Journal Article
• Authors: Koelewijn, Jacobus M.; Lutz, Martin; Detz, Remko J.; Reek, Joost N. H.
• Is Part Of: ChemPlusChem. Volume 81:Issue 10(2016)
• Page Start: 1098
• Page End: 1106
• Publication Date: 2016-10-06
• Subjects: carbon nanotubes -- catalysis -- catalyst immobilization -- electrodes -- water splitting; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cplu.201600235
• Languages: English
• ISSNs: 2192-6506

Abstract

Abstract: A strategy is reported for the immobilization of iridium‐based water oxidation catalyst3 onto fluorine‐doped tin oxide (FTO) anodes evaluated for the electrocatalytic oxidation of H2 O. The strategy is based on noncovalent π–π interactions between multiwalled carbon nanotubes (MWCNTs) and the cationic acetylammonium pyrene moiety (Pyr + ) covalently attached to a NHC IrCp*Cl2 catalytically active center (NHC=N‐heterocyclic carbene, Cp*=C5 Me5 ). The dispersive properties of the Pyr + moiety in compound 3 leads to the formation of stable MWCNT dispersions in aqueous solutions. In addition, the MWCNT/3 assembly shows activity in the Ce 4+ ‐driven oxidation of H2 O. FTO/MWCNT/3 anodes show increased current densities when used as a working electrode for the electrocatalytic oxidation of H2 O. At higher anodic polarizations initially high current densities were achieved; however, these currents prove to be non‐sustained due to delamination and degradation of the catalytically active surface. The immobilization strategy is limited to applications below 1.4 V vs normal hydrogen electrode (NHE) as oxidation of the pyrene backbone is evident at higher potentials. Abstract : Anchored : An Ir‐based water oxidation catalyst was immobilized onto fluorine‐doped tin oxide anodes and evaluated for the electrocatalytic oxidation of H2 O. The immobilization strategy is based on noncovalent π–π interactions between multiwalled carbon nanotubes and the cationic acetylammonium pyrene moiety covalently attached to the active catalyst (see figure).