Supplementary data for the article: Savić, B. G.; Stanković, D. M.; Živković, S. M.; Ognjanović, M. R.; Tasić, G. S.; Mihajlović, I. J.; Brdarić, T. P. Electrochemical Oxidation of a Complex Mixture of Phenolic Compounds in the Base Media Using PbO2-GNRs Anodes. Applied Surface Science 2020, 529, 147120. https://doi.org/10.1016/j.apsusc.2020.147120

Supplementary material for: [https://doi.org/10.1016/j.apsusc.2020.147120]Related to published version: [https://cherry.chem.bg.ac.rs/handle/123456789/4177

Na zelenom putu inovacija – vodonik iz laserski potpomognute alkalne elektrolize

The dominant problem that needs to be solved today is the issue of energy sources and how to use them, which must be ecological and sustainable - in a word, green. As the best candidate for a global solution to this problem, hydrogen produced electrolytically stood out as a green fuel with no carbon footprint. However, for a hydrogen-based economy to have a realistic and sustainable perspective in the future, it largely depends on its efficient and economically viable production that would meet the market's needs. Special attention in this paper is devoted to the influence of laser radiation on the possibility of improving the process of alkaline electrolysis for obtaining hydrogen, as well as on increasing the amount of separated hydrogen when the electrolytic cell is directly irradiated with a laser beam during the electrolysis process itself. After the experiments, it was determined that the application of direct irradiation of the electrolyte with a green laser at 532 nm wavelength significantly increases the amount of hydrogen produced and reduces the voltage of the electrolytic process, which is directly related to the increase in the energy efficiency of the overall hydrogen production process.Dominantan problem koji danas treba rešiti je pitanje energenata i načina njihove upotrebe koji moraju biti ekološki i održivi – jednom rečju zeleni. Kao najbolji kandidat za globalno rešenje ovog problema istakao se vodonik proizveden elektolitičkim putem, kao zeleno gorivo bez ugljeničnih otisaka. Da bi ekonomija zasnovana na vodoniku imala realnu i održivu perspektivu u budućnosti, u velikoj meri zavisi od njegove efikasne i ekonomski podobne proizvodnje koja bi zadovoljila potrebe tržišta. Posebna pažnja u ovom radu posvećena je uticaju laserskog zračenja na mogućnost poboljšanja procesa alkalne elektrolize za dobijanje vodonika, kao i na povećanje količine izdvojenog vodonika pri direktnom ozračivanju elektrolitičke ćelije laserskim snopom tokom samog procesa elektrolize. Nakon izvršenih eksperimenata utvrđeno je da se primenom direktnog ozračivanja elektrolita zelenim laserom talasne dužine 532 nm u značajnoj meri povećava količina proizvedenog vodonika i smanjuje napon elektrolitičkog procesa, što je u direktnoj vezi sa povećanjem energetske efikasnosti ukupnog procesa dobijanja vodonika

Kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel

The kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel (PAM) has been investigated. Thermogravimetric and conversion dehydration curves were recorded at various heating rates 5-30 K min(-1). The conversion dehydration curves at all investigated temperatures can be mathematically described using the logistic regression function in entire. It was found that activation energy complexly changes with the increasing dehydration degree. Physical meaning of the parameters of logistic function (band w) is given. It was established that, during the dehydration, changes in the fluctuating hydrogel structure occur, and that limiting step on the kinetics of hydrogel dehydration have rate of structural rearrangement of hydrogel (actual relaxation mechanism). A procedure for determining the dependence of effective activation energy on temperature and dehydration degree, based on logistic function, is exposed. Possible explanation for the existence of negative values of activation energy in the certain range of temperature, is given. (C) 2010 Elsevier B.V. All rights reserved

Electrocatalytic activation of Ni electrode for hydrogen production by electrodeposition of Co and V species

Hydrogen is considered to be the most promising candidate as a future energy carrier. One of the most used technologies for the electrolytic hydrogen production is alkaline water electrolysis. Electrode materials used in alkaline water electrolysis are mainly made from Ni or Ni-based alloys due to their desirable mechanical and chemical stability in hot and alkaline solution. Considerable research effort has been conducted on enhancement of electrocatalytic activity of Ni electrodes. Electrocatalytic activity of Ni electrode for the hydrogen evolution reaction (HER) in alkaline solution was compared to the electrode made from electrodeposition of Co and Co-V species on Ni support electrode using ac and dc electrochemical techniques. Analysis of Tafel polarization curves for the HER in alkaline solution reveals an increased electrocatalytic activity of the electrodeposited electrodes if compared to the Ni, This was additionally proved by measuring energy input (overpotential) for the given hydrogen production (fixed current density) and vice versa. Electrochemical impedance spectroscopy was applied in order to investigate the obtained effect of electrodeposited electrodes. It was found that the apparent electrochemical surface of investigated electrodes was significantly increased by the process of electrodeposition. (c) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved

Non-noble metal catalyst for a future Pt free PEMFC

We have investigated the possibility of developing high-performance, cost-effective and durable non-noble Co metal electrocatalyst for PEMFC. In this work we applied electrodeposition process for PEMFC electrode preparation that is very efficient and far simpler than any other investigated method. The fuel cell with electrodeposited Co as anode catalyst has shown satisfying performance level. In determining FCs operating conditions, subsequent electrochemical impedance and output power measurements were done, which enable the insight into the Co catalyst based anode behavior. Structure analysis of the electrodeposited anode layer was done by means of SEM and EDS technique. Although the Pt catalyst has higher efficiency, its cost performance ratio is significantly lower than for the Co catalyst, thus this investigation gives interesting possibilities in area of stationary fuel cell application. (C) 2009 Elsevier B.V. All rights reserved

Electrochemical H/D isotope effects in PEM fuel cell

An electrochemical H/D separation system consisting of electrolyzer and PEM fuel cell has been proposed. Isotope separation could be important as a part of the energy saving process in an energy-hydrogen-energy cycle. Any transfer of energy into hydrogen or vice versa induces change of the H/D isotope ratio, which can be considered, as a method to produce heavy water as by-product. In this way, the separation efficiency can contribute to the overall efficiency of the cycle. (c) 2008 Elsevier B.V. All rights reserved

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

Non-noble metal catalyst for a future Pt free PEMFC

We have investigated the possibility of developing high-performance, cost-effective and durable non-noble Co metal electrocatalyst for PEMFC. In this work we applied electrodeposition process for PEMFC electrode preparation that is very efficient and far simpler than any other investigated method. The fuel cell with electrodeposited Co as anode catalyst has shown satisfying performance level. In determining FCs operating conditions, subsequent electrochemical impedance and output power measurements were done, which enable the insight into the Co catalyst based anode behavior. Structure analysis of the electrodeposited anode layer was done by means of SEM and EDS technique. Although the Pt catalyst has higher efficiency, its cost performance ratio is significantly lower than for the Co catalyst, thus this investigation gives interesting possibilities in area of stationary fuel cell application. (C) 2009 Elsevier B.V. All rights reserved

Energy consumption and stability of the Ni-Mo electrodes for the alkaline hydrogen production at industrial conditions

Hydrogen production via electrolysis of water from alkaline aqueous electrolytes is a well-established conventional technology. However, the cost of hydrogen produced in such a way is high. To improve this process we have investigated in situ activation with Ni-Mo electrocatalytic material for electrodes. This two d-metal combination possesses one of the highest known activities for the HER. Ni-Mo based catalyst was not applied at industrial applications yet, because under industrial conditions (high temperature and concentrated alkaline solution), permanent destruction of the Ni-Mo alloy coating occurs. The most important result of this study is that the Ni-Mo deposit obtained by in situ activation, under industrial conditions, exhibit long term stability and the electrodes retain their high catalytic performance. The process of adding Ni-Mo activating compounds in situ exhibits savings of the energy consumption that can go beyond 20% in some cases. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

A study on the Co-W activated Ni electrodes for the hydrogen production from alkaline water electrolysis - Energy saving

Hydrogen is considered to be the most promising candidate as a future energy carrier. One of the most used technologies for the electrolytic hydrogen production is alkaline water electrolysis. However, due to high energy requirements of about 4.5-5 kWh/Nm(3) H(2) in most industrial electrolysers, the cost of hydrogen produced in such a way is high. There are various attempts to overcome this problem, like zero-gap cell geometry, development of new diaphragm materials, development of new electrocatalytic materials for electrodes, etc. In continuous search to improve this process using advanced electrocatalytic materials for the hydrogen evolution reaction (HER), based on transition metal series, catalyst based of cobalt and wolfram was investigated as cathode material. On the basis of the results of our experiments, there is a strong indication that the Co-W catalyst reduces energy needs per mass unit of hydrogen produced for more than 20% in some cases. Objective of this work was to investigate the electrocatalytic efficiency using quasi-potentiostatic, galvanostatic and impedance spectroscopy techniques. 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 Co-W 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 of the Co-W catalyst. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved