Electrodeposited nickel–zinc alloy nanostructured electrodes for alkaline electrolyzer

2022

Abstract Over the last decade, as a consequence of the global decarbonization process, the interest towards green hydrogen production has drastically increased. In particular a substantial research effort has focused on the efficient and affordable production of carbon-free hydrogen production processes. In this context, the development of more efficient electrolyzers with low-cost electrode/electrocatalyst materials can play a key role. This work, investigates the fabrication of electrodes of nickel-zinc alloys with nanowires morphology cathode for alkaline electrolyzers. Electrodes are obtained by the simple method of template electrosynthesis that is also inexpensive and easily scalable.…

Pd-Co-Based Electrodes for Hydrogen Production by Water Splitting in Acidic Media

2023

To realize the benefits of a hydrogen economy, hydrogen must be produced cleanly, efficiently and affordably from renewable resources and, preferentially, close to the end-users. The goal is a sustainable cycle of hydrogen production and use: in the first stage of the cycle, hydrogen is produced from renewable resources and then used to feed a fuel cell. This cycle produces no pollution and no greenhouse gases. In this context, the development of electrolyzers producing high-purity hydrogen with a high efficiency and low cost is of great importance. Electrode materials play a fundamental role in influencing electrolyzer performances; consequently, in recent years considerable efforts have b…

Evolutionary Design Optimization of an Alkaline Water Electrolysis Cell for Hydrogen Production

2020

Hydrogen is an excellent energy source for long-term storage and free of greenhouse gases. However, its high production cost remains an obstacle to its advancement. The two main parameters contributing to the high cost include the cost of electricity and the cost of initial financial investment. It is possible to reduce the latter by the optimization of system design and operation conditions, allowing the reduction of the cell voltage. Because the CAPEX (initial cost divided by total hydrogen production of the electrolyzer) decreases according to current density but the OPEX (operating cost depending on the cell voltage) increases depending on the current density, there exists an optimal cu…

Ni alloy nanowires as high efficiency electrode materials for alkaline electrolysers

2021

Abstract The fabrication and characterization of nickel-alloy electrodes for alkaline electrolysers is reported. Three different alloys (Ni–Co, Ni–Zn and Ni–W) at different composition were studied in order to determine the optimum condition. Nanostructured electrodes were obtained by template electrodeposition into a nanoporous membrane, starting from aqueous solution containing the two elements of the alloy at different concentrations. Composition of alloys can be tuned by electrolyte composition and also depends on the difference of the redox potential of elements and on the presence of complexing agents in deposition bath. Electrochemical and electrocatalytic tests, aimed at establishin…

Nanostructured Ni Based Anode and Cathode for Alkaline Water Electrolyzers

2019

Owing to the progressive abandoning of the fossil fuels and the increase of atmospheric CO2 concentration, the use of renewable energies is strongly encouraged. The hydrogen economy provides a very interesting scenario. In fact, hydrogen is a valuable energy carrier and can act as a storage medium as well to balance the discontinuity of the renewable sources. In order to exploit the potential of hydrogen it must be made available in adequate quantities and at an affordable price. Both goals can be potentially achieved through the electrochemical water splitting, which is an environmentally friendly process as well as the electrons and water are the only reagents. However, these devices stil…

Ni-Fe alloy nanostructured electrodes for water splitting in alkaline electrolyser

2021

Abstract In this work, nickel-iron alloy nanostructured electrodes obtained by template electrosynthesis method are investigated for both hydrogen and oxygen evolution reactions. Electrodes consist of nanowire arrays with high surface area that are able to ensures a high electrolytic activity. To obtain different alloy compositions, the concentration of the elements in the deposition baths is appropriately tuned. Results show that the composition of nanowires does not change linearly with the composition of deposition bath but are richer in Fe. Nanostructured electrodes are tested as both cathodes and anodes in 30 wt% KOH aqueous solution, at room temperature to determine the best alloy com…

Eulerian two-fluid model of alkaline water electrolysis for hydrogen production

2020

Hydrogen storage is a promising technology for storage of renewable energy resources. Despite its high energy density potential, the development of hydrogen storage has been impeded, mainly due to its significant cost. Although its cost is governed mainly by electrical energy expense, especially for hydrogen produced with alkaline water electrolysis, it is also driven by the value of the cell tension. The most common means of electrolyzer improvement is the use of an electrocatalyst, which reduces the energy required for electrochemical reaction to take place. Another efficient means of electrolyzer improvement is to use the Computational Fluid Dynamics (CFD)-assisted design that allows the…

Pumps as turbines regulation study through a decision-support algorithm

2022

The water distribution network (WDN) is subject to water leakages due to pipes breaking, which induces a wastage of water and overconsumption of power for pumps. Leakages are directly related to pressure in the pipes. To reduce leakages, pressure reducing valves (PRV) are installed in water distribution networks to reduce pressure in the pipes. However, pressure reduction induces a loss of energy which is wasted within the PRV. To recover a part of this energy, pressure reducing valves can be replaced by using pumps as turbines (PATs). Since head and flow rates are variable in the WDN, it is necessary to regulate the PAT, which does not function properly under variable upstream conditions. …

Suitability of the VOF Approach to Model an Electrogenerated Bubble with Marangoni Micro-Convection Flow

2022

When a hydrogen or oxygen bubble is created on the surface of an electrode, a micro-convective vortex flow due to the Marangoni effect is generated at the bottom of the bubble in contact with the electrode. In order to study such a phenomenon numerically, it is necessary to be able to simulate the surface tension variations along with a liquid-gas interface, to integrate the mass transfer across the interface from the dissolved species present in the electrolyte to the gas phase, and to take into account the moving contact line. Eulerian methods seem to have the potential to solve this modeling. However, the use of the continuous surface force (CSF) model in the volume of fluid (VOF) framew…

Ni-Based Alloy Nanostructured Electrodes for Alkaline Electrolyzers

In water alkaline electrolyzer field, the development of Nickel-based nanostructured electrode is one of the possible ways to improve the water electrolysis efficiency