Influence of ternary ionic activators in the improvement of energy efficiency of alkaline electrolyzer

Koncept koji se uobičajeno naziva vodonična energija, svodi se na primenu vodonika kao medijuma za manipulaciju energijom (proizvodnja, skladištenje, transport, primena). Najintenzivnije izučavana elektrodna reakcija, kako sa teorijskog, danas sve više i sa praktičnog aspekta, je reakcija dobijanja vodonika. Najperspektivniji način dobijanja vodonika na ovom stupnju razvoja tehnike predstavlja elektroliza vode, a debalans između termodinamički neophodnog minimuma energetskog ulaganja i stvarne potrošnje pri konačnim intenzitetima (gustinama struje), moguće je smanjiti jedino elektrokatalizom i razvojem elektrokatalizatora...Concept which is commonly known as hydrogen energy, comprises use of hydrogen as the medium for energy management (production, storage, transport, application). Most widely studied electrode reaction from the theoretical and practical aspect is hydrogen evolution reaction (HER). Water electrolysis is among the most perspective methods at this point of technical development. Further improvement of efficacy and cost reduction is possible only through development of electrocatalysts..

Enhanced Catalytic Activity and Energy Savings with Ni-Zn-Mo Ionic Activators for Hydrogen Evolution in Alkaline Electrolysis

Green hydrogen produced by alkaline electrolysis is a promising solution to address the world’s increasing energy demand while mitigating greenhouse gas emissions. However, the efficient and cost-effective production of green hydrogen via alkaline electrolysis requires improvements. This paper presents an in situ activation process that simplifies the alkaline electrolysis technology while enhancing the catalytic activity of electrodes for the hydrogen evolution reaction. The aim of this research is to enhance the energy efficiency of alkaline electrolysis and decrease the energy consumption for hydrogen production. To achieve this goal, ionic activators comprising Ni, Zn, and Mo were incorporated into the standard electrolyte solution. Our results demonstrate that the anticipated improvement in the catalytic activity of the d-metal combination, surpassing even that of precious metals, has been successfully attained. As a result, a 20% reduction in energy consumption (REC) for the hydrogen produced has been observed. The catalytic activity of the added activators for the hydrogen evolution reaction was discussed by analyzing the mechanism of the reaction via Tafel analysis and EIS techniques. These findings offer a promising approach to improve alkaline electrolysis and enhance the production of green hydrogen

Ab Initio Study of Graphene Interaction with O-2, O, and O-

A systematic ab initio (DFT-GGA) study of adsorption of various oxygen species on graphene has been performed in order to find out general trends and provide a good starting point to analyze the oxidation of more complex carbon materials. Particular attention was paid to finding an appropriate supercell model. According to our findings, atomic O is characterized by stable adsorption on graphene and very strong adsorption on defective graphene. On the other hand, O-2 does not adsorb on graphene and is allowed to diffuse freely to the defect, where it is expected to dissociate into two strongly adsorbed O atoms. The obtained results were compared with available theoretical data in the literature and good agreement was achieved

Influence of ternary ionic activators in the improvement of energy efficiency of alkaline electrolyzer

Koncept koji se uobičajeno naziva vodonična energija, svodi se na primenu vodonika kao medijuma za manipulaciju energijom (proizvodnja, skladištenje, transport, primena). Najintenzivnije izučavana elektrodna reakcija, kako sa teorijskog, danas sve više i sa praktičnog aspekta, je reakcija dobijanja vodonika. Najperspektivniji način dobijanja vodonika na ovom stupnju razvoja tehnike predstavlja elektroliza vode, a debalans između termodinamički neophodnog minimuma energetskog ulaganja i stvarne potrošnje pri konačnim intenzitetima (gustinama struje), moguće je smanjiti jedino elektrokatalizom i razvojem elektrokatalizatora...Concept which is commonly known as hydrogen energy, comprises use of hydrogen as the medium for energy management (production, storage, transport, application). Most widely studied electrode reaction from the theoretical and practical aspect is hydrogen evolution reaction (HER). Water electrolysis is among the most perspective methods at this point of technical development. Further improvement of efficacy and cost reduction is possible only through development of electrocatalysts..

Influence of ternary ionic activators in the improvement of energy efficiency of alkaline electrolyzer

Koncept koji se uobičajeno naziva vodonična energija, svodi se na primenu vodonika kao medijuma za manipulaciju energijom (proizvodnja, skladištenje, transport, primena). Najintenzivnije izučavana elektrodna reakcija, kako sa teorijskog, danas sve više i sa praktičnog aspekta, je reakcija dobijanja vodonika. Najperspektivniji način dobijanja vodonika na ovom stupnju razvoja tehnike predstavlja elektroliza vode, a debalans između termodinamički neophodnog minimuma energetskog ulaganja i stvarne potrošnje pri konačnim intenzitetima (gustinama struje), moguće je smanjiti jedino elektrokatalizom i razvojem elektrokatalizatora...Concept which is commonly known as hydrogen energy, comprises use of hydrogen as the medium for energy management (production, storage, transport, application). Most widely studied electrode reaction from the theoretical and practical aspect is hydrogen evolution reaction (HER). Water electrolysis is among the most perspective methods at this point of technical development. Further improvement of efficacy and cost reduction is possible only through development of electrocatalysts..

Characterization of the Ni-Mo catalyst formed in situ during hydrogen generation from alkaline water electrolysis

Objective of this work was to investigate the electrocatalytic efficiency using quasi-potentiostatic, galvanostatic and impedance spectroscopy techniques of the Ni-Mo catalysts obtained by in situ electrodeposition in an alkaline, 6 M KOH, electrolyser. In accordance to our previous studies, synergetic effect is observed, with its maximum at industrial conditions (high temperature and current density). The Tafel slopes are around 120 mV and exchange current densities are close to 10(-2) mA cm(-2) (three orders of magnitude higher compared to the bulk Ni). moreover, formed deposit possess high stability during prolonged electrolysis. Results are presented to show the Tafel slopes, the exchange current densities, the apparent energy of activation, the apparent electrochemical surface and the stability of in situ formed Ni-Mo catalyst. Results suggest to significant catalytic performance not only from the increase of the real surface area of electrodes, but also from the true catalytic effect. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

Energy saving in electrolytic hydrogen production using Co-Cr activation - Part I

The manuscript presents a report on the improved efficiency of alkaline electrolytic production of hydrogen by in situ adding directly into the electrolyte during the electrolytic process, cobalt and chrome based ionic activators. During electrolysis process the ionic activators deposit on the surface of the Ni cathode electrode and form an active, porous structure of high surface area. This simple process of adding in situ activating compounds directly into electrolyser is reducing the energy requirements per mass unit of hydrogen produced for about 15%, compared to non-activated system, for a number of current densities in a wide temperature range. Energy saving is higher at higher temperatures and on higher current densities. Structural and morphological characteristic of deposit formed on the cathode during the electrolytic process after in situ addition of activators, reveal interesting electrode surface pattern with highly developed surface area and uniform distribution of the pores. Obtained deposit also exhibit a long term stability. Copyright (c) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

Enhanced Performance of the Solid Alkaline Fuel Cell Using PVA-KOH Membrane

Poly(vinyl alcohol) (PVA) is a polyhydroxy polymer, which is very common in practical applications because of its easy preparation and biodegradability. In this work, the alkaline solid polymer electrolyte membrane, based on potassium hydroxide doped PVA, was proposed for the fuel cell applications, aiming at a new cost-effective, easy preparing and chemical stable alkaline anion exchange membrane using physical cross-linking procedure. The membrane electrode assemblies (MEAs) using KOH doped PVA as membranes, were prepared with commercial platinum catalyst. We have investigated the performance of the solid alkaline fuel cell (SAFC) and results are presented to show current-voltage characteristics

Energy consumption of the electrolytic hydrogen production using Zn-Co-Mo based activators-Part I

Alkaline water electrolysis is one of the easiest methods for hydrogen production. Simplicity and usefulness are the two main features that characterize this method. The challenges for widespread use of water electrolysis are to reduce energy consumption, cost, durability and safety. In our investigation we obtain the results about energy efficiency system with the addition of ionic activators (i.a.) - Co(en)(3)Cl-3, Na2MoO4 and ZnCl2, in 6 M KOH solution. The requirements per mass unit of hydrogen produced are reduced up to 15% just using simplified process of the in situ activation with d-metals. The most important result of this study is that obtained deposit exhibit long-term stability at elevated temperatures and high current densities, like industrial conditions. (C) 2012 Elsevier B.V. All rights reserved

Electrocatalytic activity of ZnCoMo based ionic activators for alkaline hydrogen evolution-Part II

Nickel electrodes are widely used in industrial water electrolysis cells for electrochemical production of hydrogen. To avoid extensive deactivation problems and enhance the efficiency of the electrolyser cathode, in this work in situ activation is proposed using ionic activator (i.a.) based on combination of three d-metals: Zn, Co and Mo. Polarization curves, obtained at different temperatures (303-343 K), reveal that the addition of ZnCoMo based La. did not change reaction mechanism when compared to the HER mechanism on nickel cathode in standard electrolyte. The electrochemical impedance spectroscopy measurements were employed to further investigate the origin of obtained electrocatalytic effect on the HER. The morphology of obtained coatings was examined by scanning electron microscopy. (C) 2012 Elsevier B.V. All rights reserved