Behavior of the Ru-bda Water Oxidation Catalyst Covalently Anchored on Glassy Carbon Electrodes

Abstract

, (N-N 2 is 4-(pyridin-4-yl) benzenediazonium) in acetone allows grafting it onto graphite electrodes (GC). Multiple cycling voltammetric experiments on the same electrode generates a new hybrid material GC-4 with the Ru-aqua complex anchored on the graphite surface. GC-4. While the complex anchored on the graphite surface is an active water oxidation catalyst, as characterized at pH = 7.0 via electrochemical techniques and XAS, it has worse performance than in the homogeneous phase and decomposes to form RuO 2 at the electrode surface. However, we find that the resulting metal oxide attached to the GC electrode, GC-RuO 2 , is a very fast and rugged heterogeneous water oxidation catalyst with TOF i s of 300 s -1 and TONs >45000. The observed performance is comparable to the best electrocatalysts reported, so far, at neutral pH. Keywordswater oxidation catalysis, electrocatalysis, water splitting, Ru complexes, modified graphite electrodes, heterogeneous water oxidation catalysis, RuO 2 . TOCThe performance of new hybrid materials based on molecular Ru-bda type of complexes anchored on graphitic surfaces as water oxidation catalysts, is described. The nature of the active species is uncovered based on electrochemical techniques and XAS spectroscopy.

Intramolecular Proton Transfer Boosts Water Oxidation Catalyzed by a Ru Complex

“…1,2,3,4,5,6 Efficient functionality for fast and oxidatively rugged 7,8 performance at neutral pH can provide durability for sufficiently long times as necessary for practical applications. 9,10 Here, we introduce and characterize a new family of Ru complexes, including compound [Ru IV (OH)(tda-κ-N 3 O)(py) 2 ] + with tda 2-=[2,2':6',2''-terpyridine]-6,6''-dicarboxylate, found to be an impressive water oxidation catalyst both under neutral and alkaline conditions.…”

Electrochemical Water Oxidation Catalyzed by an In Situ Generated α‐Co(OH)2 Film on Zeolite‐Y Surface

“…[1][2][3][4][5][6][7] Among these, ah eterogeneous electrocatalyst is of particulari nterest because it offers extra stability, and the relevant electrocatalytic method can directly be implemented into devices. [8][9][10][11][12] The known heterogeneous WOCs are metal oxides, including spinel oxides, monomeric, dimeric,a nd tetrameric molecular complexes, polyoxometalates (POMs) and POM-supported metal complexes,v arious nano-materials, electrodeposited metals from aqueous solutionso fm etal salts, amorphous metal-oxide thin-films, and metal-organic framework (MOF)-containing compounds. [2,[13][14][15][16][17] Although this large body of molecular transition-metal catalysts and active metal-oxide materials has been developed for water oxidation, substantial challenges remain for the ultimate goal of an efficient, inexpensive, and robust electrocatalyst.…”

Neutral Water Splitting Catalysis with a High FF Triple Junction Polymer Cell

“…These values were used to fabricate triple-junction devices with measured conversion efficiencies up to 8.7% under AM . By using the molecular catalyst precursor methodology 25 we have a full control of the starting monolayer of ruthenium deposited on the electrode, that upon oxidative scans, converts into small RuO 2 particles with a very high surface area available for the water oxidation reaction. Environmental scanning electron microscopy analysis did not show the RuO 2 nanoparticles due to their small size, below the detection limit of the instrument.…”

“…The preparation of the electrode is based on using a ruthenium molecular precursor 24 , 25 that interconverts into the final RuO 2 active species upon electrochemical treatment, details on the synthesis and characterization of this anode can be found in Ref. [25].…”