Bilayer Vesicles as a Noncovalent Immobilization Platform of Electrocatalysts for Energy Conversion in Neutral Aqueous Media

Abstract

AbstractWe show that synthetic [FeFe]‐hydrogenase mimics embedded within liposomes can be immobilized on high‐surface‐area carbon blacks for the construction of a three‐dimensional (3D) electrode for H2 production in neutral aqueous media. In this design, the bilayer vesicles (liposomes) serve as a water‐insoluble electrocatalyst carrier, facilitating access of the embedded catalysts to aqueous solution. Fast electron‐transfer rates and low overpotentials are achieved compared to water‐soluble catalysts. The electron‐transfer rate constant between the embedded [(μ‐bdt)Fe2(CO)6] (bdt=1,2‐benzenedithiolate; 1) and the electrode is estimated to be 1.33±0.15 s−1. Immobilized [(μ,κ2‐bdt‐Me)(μ‐PPh2)Fe2(CO)5] (Me=methyl; 3) is able to catalyze H2 production in Na2SO4(aq) solution (pH=7) at −1.06 V (vs. SHE) with an overpotential of approximately 400 mV. The reported general method for the construction of 3D electrodes paves the way to potential applications of molecular catalysts in energy devices.