Despite their potential for facilitating high activity, thin-film conducting polymer supports have, historically, expedited only relatively weak performances in catalytic water oxidation (with current densities in the μA/ cm2 range). In this work, we have investigated the conditions under which thin-film conducting polymers may synergistically amplify catalysis. A composite conducting polymer film has been developed that, when overcoated on a bare Pt electrode, amplifies its catalytic performance by an order of magnitude (into the mA/cm2 range). When poised at 0.80 V (vs Ag/AgCl) at pH 12, a control, bare Pt electrode yielded a current density of 0.15 mA/cm2 for catalytic water oxidation. When then overcoated with a composite poly(3,4-ethylenedioxythiophene) (PEDOT) film containing nanoparticulate Ni (nano-Ni) catalyst and reduced graphene oxide (rGO) conductor in the specific molar ratio of 4.5 (C; PEDOT): 1 (Ni): 9.5 (C; other), the electrode generated water oxidation current densities of 1.10-1.15 mA/cm2 under the same conditions (over >50 h of operation; including a photocurrent of 0.55 mA/cm2 under light illumination of 0.25 sun). Control films containing other combinations of the above components, yielded notably lower currents. These conditions represent the most favorable for water oxidation at which PEDOT does not degrade. Studies suggested that the above composite contained an optimum ratio of catalyst density to conductivity and thickness in which the PEDOT electrically connected the largest number of catalytic sites (thereby maximizing the catalytically active area) by the shortest, least-resistive pathway (thereby minimizing the Tafel slope). That is, the amplification appeared to be created by a synergistic matching of the connectivity, conductivity, and catalytic capacity of the film. This approach provides a potential means for more effectively deploying thin-film conducting polymers as catalyst supports.

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hydrogen. [1] This is likely to be less than 10% by volume as this is the maximum that natural gas pipelines can accommodate without downstream engineering modifications. [1] Natural gas is primarily composed of methane (CH 4 ), but also contains quantities of ethane, propane, and heavier hydrocarbons. [1] If the hydrogen-enriched natural gas streams of P2G could be used to generate electricity, then this would provide additional economic benefits. A hydrogenoxygen fuel cell capable of doing so would, however, need to be successfully and sustainably fueled by the low levels of hydrogen present. That is, the fuel cell would have to be capable of utilizing the <10% hydrogen blend as a fuel. The most widely used class of hydrogen-oxygen fuel cell at present is the proton exchange membrane (PEM) fuel cell. Studies have demonstrated that methane acts an inert gas when fed through the anode of a PEM. [2a,b] PEM fuel cells have, moreover, been shown to be capable of generating electrical power when fueled with a blend of 5% hydrogen in nitrogen (N 2 ), [2c] which also acts as an inert gas in such cells. However, at such high dilutions, PEM fuel cells are known to experience significant resistances arising from proton diffusion limitations due to the solid-state PEM electrolyte and its interface with the solid catalysts. [2d] Thus, for example, the charge transfer resistance in a PEM fuel cell increased from 330 mΩ cm 2 when fueled with pure hydrogen, to 780 mΩ cm 2 when the hydrogen was diluted to 5% by volume with nitrogen-a 240% increase (all feedstock gases humidified to 91%). [2c] It is perhaps for this reason that PEM fuel cells capable of operating with 5-10% hydrogen in methane do not appear to have ever been proposed or studied.Another reason may involve the need to humidify feedstock gases in PEM fuel cells in order to maintain the conductivity of the proton exchange membrane. Natural gas transported by pipeline is routinely extremely dry. [1] If a PEM fuel cell were used to extract electricity from hydrogen-enriched natural gas, then the gas would first have to be humidified before entering the cell. It may then also have to be dehumidified after leaving the cell and before re-entering the natural gas pipeline.An alternative class of hydrogen-oxygen fuel cell is the alkaline fuel cell (AFC). AFCs were one of the first fuel cell technologies applied to practical power generation, with applications in Numerous electric and gas utilities are actively pursuing "power-to-gas" technology, which involves using unwanted, excess renewable energy to manufacture hydrogen gas (H 2 ) that is then injected into the existing natural gas pipeline network in 5-10% by volume. This work reports an alkaline fuel cell that has the potential to harness such gas mixtures for downstream generation of electric power. The fuel cell, which employs novel Gortex-based electrodes layered with Pd/Pt catalysts, generates electricity remarkably efficiently when fuelled with methane (CH 4 ) containing 5% hydrogen. Methane constitutes ...

In this work we report a novel liquid–acid electrochemical cell containing Gortex-based gas diffusion electrodes, layered with suitable catalysts and current collectors, that is capable of sustainably extracting pure hydrogen from methane mixtures containing as little as 5% hydrogen.