An electrochemical cell with Gortex-based electrodes capable of extracting pure hydrogen from highly dilute hydrogen-methane mixtures

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 extractin g pure hydrogen from methane mixtures containing as little as 5% hydrogen. The origin of its efficiency appears to derive from the solid-liquid interface between the solid Gortex electrodes and the liquid electrolyte, as well as the high proton conductivity of the electrolyte. This interface and electrolyte exhibit an efficiency for reaction that greatly exceeds that achieved by the comparable solid-solid interface and proton conductor in Proton Exchange Membrane Fuel Cell (PEMFC) technology. We report hydrogen yields and recovery by the cell from a range of methane-hydrogen mixtures. Electrochemical impedance spectroscopy has been used to characterise the cell and to illuminate the system limitations

Alkaline Fuel Cells with Novel Gortex-Based Electrodes are Powered Remarkably Efficiently by Methane Containing 5% Hydrogen

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 the major component of natural gas. The fuel cell has been studied over a range of hydrogen to methane ratios using Tafel plots and electrochemical impedance spectroscopy. These show that, in terms of fundamental operation, there is, astonishingly, almost no difference between using pure hydrogen and 5% hydrogen in methane, as the fuel. The Gortex electrodes and alkaline electrolyte are clearly able to utilize the dilute hydrogen as a fuel with remarkable efficiency. The methane acts as an inert carrier gas and is not consumed

Field dependent anisotropy change in a supramolecular Mn(II)-[3x3] grid

The magnetic anisotropy of a novel Mn(II)-[3x3] grid complex was investigated by means of high-field torque magnetometry. Torque vs. field curves at low temperatures demonstrate a ground state with S > 0 and exhibit a torque step due to a field induced level-crossing at B* \approx 7.5 T, accompanied by an abrupt change of magnetic anisotropy from easy-axis to hard-axis type. These observations are discussed in terms of a spin Hamiltonian formalism.Comment: 4 pages, 4 figures, to be published in Phys. Rev. Let

Towards hydrogen energy: progress on catalysts for water splitting

This article reviews some of the recent work by fellows and associates of the Australian Research Council Centre of Excellence for Electromaterials Science (ACES) at Monash University and the University of Wollongong, as well as their collaborators, in the field of water oxidation and reduction catalysts. This work is focussed on the production of hydrogen for a hydrogen-based energy technology. Topics include: (1) the role and apparent relevance of the cubane-like structure of the Photosystem II Water Oxidation Complex (PSII-WOC) in non-biological homogeneous and heterogeneous water oxidation catalysts, (2) light-activated conducting polymer catalysts for both water oxidation and reduction, and (3) porphyrin-based light harvesters and catalysts

Yeast biodiversity in vineyard environments is increased by human intervention

One hundred and five grape samples were collected during two consecutive years from 33 locations on seven oceanic islands of the Azores Archipelago. Grape samples were obtained from vineyards that were either abandoned or under regular cultivation involving common viticultural interventions, to evaluate the impact of regular human intervention on grape yeast biota diversity in vineyards. A total of 3150 yeast isolates were obtained and 23 yeast species were identified. The predominant species were Hanseniaspora uvarum, Pichia terricola, Starmerella bacillaris and Issatchenkia hanoiensis. The species Barnettozyma californica, Candida azymoides and Pichia cecembensis were reported in grapes or wine-associated environments for the first time. A higher biodiversity was found in active vineyards where regular human intervention takes place (Shannon index: 1.89 and 1.53 in the first and second years, respectively) when compared to the abandoned ones (Shannon index: 0.76 and 0.31). This finding goes against the assumptions that human intervention can destroy biodiversity and lead to homogeneity in the environment. Biodiversity indices were considerably lower in the year with the heaviest rainfall. This study is the first to report on the grape yeast communities from several abandoned vineyards that have undergone no human intervention.Joao Drumonde Neves is the recipient of a fellowship of the Azorean Government (M321/006/F/2008) and PROEMPREGO. This work was supported by the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI), and by national funds through FCT by the projects FCOMP-01-0124-008775, PTDC/AGR-ALI/103392/2008 and PTDC/AGR-ALI/121062/2010.info:eu-repo/semantics/publishedVersio

Association between Grape Yeast Communities and the Vineyard Ecosystems

The grape yeast biota from several wine-producing areas, with distinct soil types and grapevine training systems, was assessed on five islands of Azores Archipelago, and differences in yeast communities composition associated with the geographic origin of the grapes were explored. Fifty-seven grape samples belonging to the Vitis vinifera grapevine cultivars Verdelho dos Acores (Verdelho), Arinto da Terceira (Arinto) and Terrantez do Pico (Terrantez) were collected in two consecutive years and 40 spontaneous fermentations were achieved. A total of 1710 yeast isolates were obtained from freshly crushed grapes and 1200 from final stage of fermentations. Twenty-eight species were identified, Hanseniaspura uvarum, Pichia terricola and Metschnikowia pulcherrima being the three most representative species isolated. Candida carpophila was encountered for the first time as an inhabitant of grape or wine-associated environments. In both sampling years, a higher proportion of H. uvarum in fresh grapes from Verdelho cultivar was observed, in comparison with Arinto cultivar. Qualitatively significant differences were found among yeast communities from several locations on five islands of the Archipelago, particularly in locations with distinctive agro-ecological compositions. Our results are in agreement with the statement that grape-associated microbial biogeography is non-randomly associated with interactions of climate, soil, cultivar, and vine training systems in vineyard ecosystems. Our observations strongly support a possible linkage between grape yeast and wine typicality, reinforcing the statement that different viti-cultural terroirs harbor distinctive yeast biota, in particular in vineyards with very distinctive environmental conditions.Joao Drumonde Neves is the recipient of a fellowship of the Azorean Government (M321/006/F/2008) and PROEMPREGO. This work was supported by the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI), and by national funds through FCT by the projects FCOMP-01-0124-008775, PTDC/AGR-ALI/103392/2008 and PTDC/AGR-ALI/121062/2010.info:eu-repo/semantics/publishedVersio

Creating a regular array of metal-complexing molecules on an insulator surface at room temperature

Controlling self-assembled nanostructures on bulk insulators at room temperature is crucial towards the fabrication of future molecular devices, e.g., in the field of nanoelectronics, catalysis and sensor applications. However, at temperatures realistic for operation anchoring individual molecules on electrically insulating support surfaces remains a big challenge. Here, we present the formation of an ordered array of single anchored molecules, dimolybdenum tetraacetate, on the (10.4) plane of calcite (CaCO3). Based on our combined study of atomic force microscopy measurements and density functional theory calculations, we show that the molecules neither diffuse nor rotate at room temperature. The strong anchoring is explained by electrostatic interaction of an ideally size-matched molecule. Especially at high coverage, a hard-sphere repulsion of the molecules and the confinement at the calcite surface drives the molecules to form locally ordered arrays, which is conceptually different from attractive linkers as used in metal-organic frameworks. Our work demonstrates that tailoring the molecule-surface interaction opens up the possibility for anchoring individual metal complexing molecules into ordered arrays