Flexible and Extensive Platinum Ion Gel Condensers for Programmable Catalysis

Catalytic condensers comprised of ion gels separating a metal electrode from a platinum-on-carbon active layer were fabricated and characterized to achieve more powerful, high surface area dynamic heterogeneous catalyst surfaces. Ion gels comprised of PVDF/ [EMIM]+[TFSI]- were spin coated as a 3.8 μm film on a Au surface, after which carbon sputtering of a 1.8 nm carbon film and electron-beam evaporation of 2 nm Pt clusters created an active surface exposed to reactant gases. Electronic characterization indicated that most charge condensed within the Pt nanoclusters upon application of a potential bias, with the condenser device achieving a capacitance of ~20 μF/cm^2 at applied frequencies up to 120 Hz. Maximum charge of ~10^14 |e-| cm^(-2) was condensed under stable device conditions at 200 °C on catalytic films with ~10^15 sites cm^(-2). Grazing incidence infrared spectroscopy measured carbon monoxide adsorption isobars indicating a change in CO* binding energy of ~16 kJ/mol over an applied potential bias of only 1.25 V. Condensers were also fabricated on flexible, large area Kapton substrates allowing stacked or tubular form factors that facilitate high volumetric active site densities, ultimately enabling a fast and powerful catalytic condenser that can be fabricated for programmable catalysis applications.