Search results for " electrolysis"
showing 10 items of 27 documents
High-Temperature Electrolysis of Kraft Lignin for Selective Vanillin Formation
2020
Lignin represents the largest renewable resource of aromatic moieties on earth and harbors a huge potential as a sustainable feedstock for the synthesis of biobased aromatic fine chemicals. Due to the complex, heterogeneous, and robust chemical structure of the biopolymer, the valorization is associated with significant challenges. Unfortunately, technical lignins, which are a large side stream of the pulp and paper industries, are mainly thermally exploited. In this study, technical Kraft lignin was selectively electrochemically depolymerized to the aroma chemical vanillin. Using electricity, toxic and/or expensive oxidizers could be replaced. The electrodegradation of Kraft lignin was per…
Nanostructured electrodes for hydrogen production in alkaline electrolyzer
2018
Abstract Ever-widespread employment of renewable energy sources, such as wind and sun, request the simultaneous use of effective energy storage systems owing to the intermittent and unpredictable energy generation by these sources. The most reliable storage systems currently under investigation are batteries and electrochemical cells for hydrogen production from water splitting. Both systems store chemical energy which can be converted on demand. The low power density is the weakness of the batteries while the high production cost limits currently the wide use of hydrogen from electrochemical water splitting. In this work, attention was focused on the use of nanostructured Ni as a cathode f…
Coated interconnects development for high temperature water vapour electrolysis: Study in anode atmospher
2013
International audience; High temperature water vapour electrolysis (HTE) is an efficient technology for hydrogen production. In this context, a commercial stainless steel, K41X (AISI 441), was chosen as interconnect. In a previous paper, the high temperature corrosion and the electrical conductivity were evaluated in both anode (O-2-H2O) and cathode (H-2-H2O) atmosphere at 800 degrees C. In O-2-H2O atmosphere, the formation of a thin chromia protective layer was observed. Nevertheless, the ASR parameter measured was higher than the maximum accepted value. These results, in addition with chromium evaporation measurements, proved that the K41X alloy is not suitable for HTE interconnect applic…
PEM electrolyzer characterization with carbon-based hardware and material sets
2021
Abstract The research and development of proton exchange membrane water electrolysis (PEMWE) is an upcoming and growing area due to a rising interest in hydrogen as an energy carrier. Operating conditions are harsher than in a fuel cell system, particularly because the potentials required for the oxygen evolution reaction are significantly higher. In commercial water electrolysis systems, this is compensated by typically using titanium material sets that are often protected against oxidation through coating processes. Such material choices make small scale research hardware and porous transport layers expensive and difficult to source. In this work, we show that the stability of traditional…
Performance Enhancement of Alkaline Water Electrolyzer Using Nanostructured Electrodes Synthetized by Template Electrosynthesis
2018
The increase of power generation by renewable sources is causing problems in the management of the electricity grid. In order to favor the transition from the current energy production towards renewable energy sources, it is necessary to plan strategy to develop suitable energy storage systems. Certainly, the electrochemical hydrogen production can be considered as one of the most promising storage technologies. In this work, an innovative alkaline electrolyzer is presented from its design based on the use of nanostructured electrodes up to its implementation suggested by the results of tests simulating real operation. The nanostructured electrodes were fabricated by template electrosynthes…
Evaluation of a new Cr-free alloy as interconnect material for hydrogen production by high temperature water vapour electrolysis: Study in cathode at…
2012
International audience; For economic and ecological reasons, hydrogen is considered as a major energetic vector for the future. Hydrogen production via high temperature water vapour electrolysis (HTE) is a promising technology. A major technical difficulty related to high temperature water vapour electrolysis is the development of interconnects working efficiently for a long period. Working temperature of 800 degrees C enables the use of metallic materials as interconnects. High temperature corrosion behaviour and electrical conductivity of a new Cr-free Fe-Ni-Co alloy were tested in cathode atmosphere (H-2/H2O) at 800 degrees C. The alloy exhibits a poor oxidation resistance but an excelle…
Optimisation of metallic interconnects for hydrogen production by high temperature water vapour electrolysis
2012
For economical and environmental reasons, hydrogen is considered as a major energetic vector for the future. Hydrogen production via high temperature water vapour electrolysis (HTE) is a promising technology. A major technical difficulty related to high temperature water vapour electrolysis is the development of interconnects working efficiently for a long period. Working temperature of 800°C enables the use of metallic materials as interconnects. Chromia forming alloys are among the best candidates. The interconnect material chosen in the present study is a ferritic stainless steel with 18% chromium content. High temperature corrosion resistance and electrical conductivity of the alloy was…
Nanostructured Ni–Co alloy electrodes for both hydrogen and oxygen evolution reaction in alkaline electrolyzer
2021
Abstract Ni–Co alloy nanostructured electrodes with high surface area were investigated both as a cathode and anode for an alkaline electrolyzer. Electrodes were obtained by template electrosynthesis at room temperature. The electrolyte composition was tuned in order to obtain different NiCo alloys. The chemical and morphological features of nanostructured electrodes were evaluated by EDS, XRD and SEM analyses. Results show that electrodes with different composition of Ni and Co, made of nanowires well anchored to the substrate, were obtained. For both hydrogen and oxygen evolution reactions, electrochemical and electrocatalytic tests, performed in 30% w/w KOH aqueous solution, were carried…
Hydrogen Production from Methanol-Water Solution and Pure Water Electrolysis Using Nanocomposite Perfluorinated Sulfocationic Membranes Modified by P…
2022
In this work, we report the preparation of Nafion membranes containing two different nanocomposite MF-4SC membranes, modified with polyaniline (PANI) by the casting method through two different polyaniline infiltration procedures. These membranes were evaluated as a polymer electrolyte membrane for water electrolysis. Operating conditions were optimized in terms of current density, stability, and methanol concentration. A study was made on the effects on the cell performance of various parameters, such as methanol concentration, water, and cell voltage. The energy required for pure water electrolysis was analyzed at different temperatures for the different membranes. Our experiments showed …
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.…