Fast and Persistent Electrocatalytic Water Oxidation by Co–Fe Prussian Blue Coordination Polymers

Abstract

The lack of an efficient, robust, and inexpensive water oxidation catalyst (WOC) is arguably the biggest challenge for the technological development of artificial photosynthesis devices. Here we report the catalytic activity found in a cobalt hexacyanoferrate (CoHCF) Prussian blue-type coordination polymer. This material is competitive with state-of-the-art metal oxides and exhibits an unparalleled long-term stability at neutral pH and ambient conditions, maintaining constant catalytic rates for weeks. In addition to its remarkable catalytic activity, CoHCF adds the typical properties of molecule-based materials: transparency to visible light, porosity, flexibility, processability, and low density. Such features make CoHCF a promising WOC candidate for advancement in solar fuels production.

Water Oxidation at Electrodes Modified with Earth‐Abundant Transition‐Metal Catalysts

“…[301] Ruthenium purple also showed HER activity. [302] Despite being heavily used as oxidation catalysts, the activity of PBAs for the OER was not disclosed until 2013, when we reported the electrocatalytic activity of K2xCo(3-x)[Fe(CN)6]2 (CoFePB) [303] At neutral pH this PBA exhibits kinetics comparable (if not superior) to those of metal oxides, with unparalleled long term stability. Electrodes coated with CoFePB maintain a persistent catalytic activity for weeks at neutral pH and ambient conditions.…”

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

“…[18] Thus, cobalt oxygen-evolution catalysts (Co-OECs) have received immense attentioni nr ecent years. [19][20][21][22][23][24] Among Co-OECs, CoOx has extensively been studied as an efficient catalyst that works over aw ide pH range. [25] Co 3 O 4 has also been described as aC o-OEC.…”

Electrochemical tuning of layered lithium transition metal oxides for improvement of oxygen evolution reaction

“…An effective electrocatalyst is needed to accelerate the reaction, reduce the overpotential to obtain a current density of 10 mA cm À 2 for matching with sunlight flux and thereby enhance the energy conversion efficiency. For this reason, a number of catalysts have been identified with low OER overpotentials [8][9][10][11] . The most active OER catalysts are IrO 2 or RuO 2 (refs 12,13), but the scarcity and high cost of these precious metals limit their large-scale application.…”