461363 Redox-Active Organometallic Polymers for Environmental and Energy Applications

Tuesday, November 15, 2016: 5:15 PM
Golden Gate 2 (Hilton San Francisco Union Square)
Xiao Su1, Johannes Elbert1, Kai-Jher Tan1, Timothy Jamison2 and T. Alan Hatton1, (1)Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, (2)Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA

Redox metallopolymers have been explored extensively for catalysis, energy storage and molecular recognition.1 When properly designed, these charged polymers can become powerful vehicles to tune the redox-properties at an electrode interface, due to their fast Faradaic reaction and electron-transfer properties. Here, we present nanostructured electrodes functionalized with poly(vinyl)ferrocene/carbon nanotubes (PVF-CNT) as a attractive platform for the selective separation of organic micropollutants under competitive binding, with separation factors >150 based on specific functional group recognition for harmful carboxylates, sulfonates and phosphonates, and ion-capacity >200 mg/g.2 The mechanism for this selectivity is explored through both spectroscopic, electrochemical and computational methods. In tandem, cobaltocenium-based polymer counter-electrodes (PMMAECoCp-CNT) were designed as efficient cathodes to increase pseudocapacitive charge and suppress side-reactions, especially the water reduction reaction, thus both enhancing energy storage capabilities (specific capacitance of 498 F/g) as well as increasing ion-selective behavior of the anode (98% current efficiency towards ion-selective process). The non-covalent functionalization of these organometallic polymers onto the electrodes grants cycling stability for over two days and >5000 cycles. Finally, further cathode design through ligand exchange has enabled us to develop cation-selective electrodes for both heavy-metal removal as well as aromatic organic cations – and in tandem, these asymmetric systems become highly energy-efficient systems for wastewater treatment, chemical purification and even bio-separations. This work highlights the potential of asymmetric polymer-functionalized redox-systems for electrochemical separations and energy storage, and the importance of organometallic design for selectively targeting molecular-level pollutants.


1   G. R. Whittell and I. Manners, Advanced Materials, 2007, 19, 3439-3468.

2 Su, X.; Kulik, H; Jamison, T.F.; Hatton, T. A. 2016. Anion-selective redox electrodes: electrochemically-mediated separation with organometallic interfaces. Advanced Functional Materials. Advance Article Online. DOI: 10.1002/adfm.201600079


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