Electrochemical Water Oxidation by a Catalyst‐Modified Metal–Organic Framework Thin Film. Issue 3 (15th December 2016)

• Record Type: Journal Article
• Authors: Lin, Shaoyang; Pineda‐Galvan, Yuliana; Maza, William A.; Epley, Charity C.; Zhu, Jie; Kessinger, Matthew C.; Pushkar, Yulia; Morris, Amanda J.
• Is Part Of: ChemSusChem. Volume 10:Issue 3(2017)
• Page Start: 514
• Page End: 522
• Publication Date: 2016-12-15
• Subjects: electrochemistry -- metal–organic frameworks -- ruthenium -- thin films -- water splitting; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201601181
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: Water oxidation, a key component in artificial photosynthesis, requires high overpotentials and exhibits slow reaction kinetics that necessitates the use of stable and efficient heterogeneous water‐oxidation catalysts (WOCs). Here, we report the synthesis of UiO‐67 metal–organic framework (MOF) thin films doped with [Ru(tpy)(dcbpy)OH2 ] 2+ (tpy=2, 2′:6′, 2′′‐terpyridine, dcbpy=5, 5′‐dicarboxy‐2, 2′‐bipyridine) on conducting surfaces and their propensity for electrochemical water oxidation. The electrocatalyst oxidized water with a turnover frequency (TOF) of (0.2±0.1) s −1 at 1.71 V versus the normal hydrogen electrode (NHE) in buffered solution (pH∼7) and exhibited structural and electrochemical stability. The electroactive sites were distributed throughout the MOF thin film on the basis of scan‐ratedependent voltammetry studies. This work demonstrates a promising way to immobilize large concentrations of electroactive WOCs into a highly robust MOF scaffold and paves the way for future photoelectrochemical water‐splitting systems. Abstract : MOF water oxidation : A polydisperse distribution of mononuclear ruthenium water‐oxidation catalysts throughout a zirconium‐based metal–organic framework can provide 120 times more electroactive catalytic sites than a monolayer of the same catalyst on a planar substrate. Herein, we report such a MOF approach and demonstrate that the high activity of the molecular compound is retained in the MOF.