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Proton switch for modulating oxygen reduction by a copper electrocatalyst embedded in a hybrid bilayer membrane



Molecular switches gate many fundamental processes in natural and artificial systems. Here, we report the development of an electrochemical platform in which a proton carrier switches the activity of a catalyst. By incorporating an alkyl phosphate in the lipid layer of a hybrid bilayer membrane, we regulate proton transport to a Cu-based molecular oxygen reduction reaction catalyst. To construct this hybrid bilayer membrane system, we prepare an example of a synthetic Cu oxygen reduction reaction catalyst that forms a self-assembled monolayer on Au surfaces. We then embed this Cu catalyst inside a hybrid bilayer membrane by depositing a monolayer of lipid on the self-assembled monolayer. We envisage that this electrochemical system can give a unique mechanistic insight not only into the oxygen reduction reaction, but into proton-coupled electron transfer in general.

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Figure 1: Synthesis of BTT.
Figure 2: Schematic of the hybrid bilayer membrane.
Figure 3: pH 7 voltammetry.
Figure 4: pH 5 voltammetry.
Figure 5: Proton switch evaluation.


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C.J.B. acknowledges a National Science Foundation Graduate Research Fellowship (NSF DGE-1144245) and a Springborn Fellowship. E.C.M.T. acknowledges a Croucher Foundation Scholarship. We thank Michael Cason for his assistance in preparing Au on glass substrates. We thank the US Department of Energy (DE-FG02-95ER46260) for support of this research. This work was carried out in part in the Frederick Seitz Materials Research Laboratory Central Facilities, which are partially supported by the US Department of Energy (DE-FG02-07ER46453 and DE-FG02-07ER46471).

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C.J.B., E.C.M.T., S.C.Z., A.H. and A.A.G. designed the experiments. C.J.B., E.C.M.T. and T.B.S. performed the experiments. Y.L. synthesized BTT. C.J.B., E.C.M.T., Y.L., S.C.Z., A.H. and A.A.G. wrote the paper. C.J.B., E.C.M.T., A.H. and A.A.G. analysed the data. All authors discussed the results and commented on the manuscript.

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Correspondence to Andrew A. Gewirth.

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The authors declare no competing financial interests.

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Barile, C., Tse, E., Li, Y. et al. Proton switch for modulating oxygen reduction by a copper electrocatalyst embedded in a hybrid bilayer membrane. Nature Mater 13, 619–623 (2014).

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