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This study introduces an innovative method for producing environmentally friendly hydrogen using glucose-assisted electrolysis in an alkaline Ni-based membrane-less electrochemical cell. Three sets of experiments were performed: i) cyclic voltammetry with photographic visualization of bubbles at the anode on a standard three-electrode electrochemical cell; ii) chronoamperometry experiments with in-situ O 2 measurements with an optical sensor on a gas-tight electrochemical cell and iii) gas-flow measurements in a membrane-less electrolyser. Results demonstrate that at glucose concentrations exceeding 100 mM, the Oxygen Evolution Reaction (OER) in a 1.0 M NaOH electrolyte can be entirely replaced by glucose oxidation on the Ni-based anode. Furthermore, experiments with the membrane-less electrolyser also serve as a proof-of-concept for the feasibility of removing the membrane in alkaline organic-assisted electrolysis processes. This breakthrough simplifies electrolyser design, reduces costs, and allows to use biomass-derived glucose as a renewable feedstock, advancing in the H 2 production technology. [Display omitted] • Under presence of glucose, no O 2 is produced in the OER region (1.7 V vs. RHE). • Under certain conditions, OER is completely replaced by the glucose oxidation. • Hydrogen is the unique gas produced during glucose-assisted electrolysis. • A membrane-less electrolyser can be used for glucose-assisted electrolysis. • A novel concept for simplifying electrolyser configuration is presented. [ABSTRACT FROM AUTHOR]

This work provides a novel model for solar PV – hydrogen (H 2) systems that uses weather data and electrical variables of the components to perform PV-H 2 design for different hybrid configurations. The objectives are to size and operate the systems optimally to reach a target production (Q H) and minimize cost of H 2. The component sizes and hydrogen production (Q H) are optimized by PV-EL direct coupling where the EL curves are determined by the number and area of EL cells connected to PV modules. The use of maximum power point (MPP) tracking increases the coupling factor (and Q H), but this gain is not significant vs. optimal PV-EL coupling. Battery assisted electrolysis has the advantage of reducing the EL size, showing how convenient is also to operate it at part loads (e.g., at night) so that the PV array and EL are larger to grant H 2 production, but the batteries are much more effective. The optimal configuration, design and operation will finally depend on the evolution of unit cost of the components (PV, MPPT, EL and batteries): direct coupling leads to a cost production of 5.03 Є / k g H 2 with 26 (20 cm2) EL cells per PV module; this is slightly increased by MPPT use (5.20 Є / k g H 2 ) and notably reduced with batteries (4.07 Є / k g H 2 ), but MPPT would be optimal if cost drops to 1/5 of base prices considered in this work and batteries are not favorable if cost per m2 of EL is reduced to less than 1/3 (depending on MPPT cost). • A new model for integrated hydrogen production with solar PV energy is proposed. • It considers different technologies, conditions of use and meteorological variations. • Optimum coupling of the electrolyzer and PV modules can be achieved. • Battery-assisted electrolysis for off-grid hydrogen production can be evaluated. • Economic analysis for customised designs that minimize hydrogen cost is provided. [ABSTRACT FROM AUTHOR]

The H–Fe interaction near a bcc Fe vacancy is analysed using a semi-empirical theoretical method. Calculations were performed using a Fe86 cluster with a vacancy. Hydrogen atoms are positioned in their local energy minima configurations.Changes in the electronic structure of Fe atoms near a vacancy were analysed for the system without H, with one H and with two H atoms. Fe atoms surrounding the vacancy weaken their bond when hydrogen is present. This is due to the formation of H–Fe bonds. Hydrogen influences only its nearest-neighbour Fe atoms. The H–H interaction was also analysed. For H–H distance of 0.82 A˚ an H–H association is formed, while H–Fe interaction and Fe–Fe weakening is markedly reduced, when compared with other H–H interactions. [Copyright &y& Elsevier]

Abstract: Ba0.5Sr0.5Co1−y Fe y O3−δ (y =0.1–0.9) (BSCF) oxides have been evaluated as cathode materials for intermediate solid oxide fuel cells with La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM) as electrolyte. The increase of iron content in BSCF materials results in an increase of the area-specific resistance (ASR), e.g. 0.04, 0.08 and 0.13Ωcm2 for compositions with y =0.2, 0.4 and 0.6 respectively at 1073K. The influence of iron content in BSCF oxides on the unit cell volume via high temperature X-ray diffraction, the overall electrical conductivity and the thermal expansion coefficient (TEC) has also been investigated. The lattice cell parameters for the BSCF series increase as a function of the temperature and exhibit a non-linear behaviour, with a sudden increase at around 673K due to the loss of lattice oxygen, which in turn is caused by the reduction of Co4+ and Fe4+ to lower oxidation states. This was determined by O2 temperature-programmed desorption and thermogravimetric analysis. Such oxygen non-stoichiometry results in a significant thermal expansion and conductivity change for all compositions at the same temperature. [Copyright &y& Elsevier]