Green Hydrogen Renewable Energy Based Society for Sustainable Economic Development-Challenges and Perspectives

Green Hydrogen Renewable Energy Based Society for Sustainable Economic Development-Challenges and Perspectives Nevenka R. Elezovic University of Belgrade – Institute for Multidisciplinary Research, Center of Excellence for Green Technologies, Kneza Viseslava 1, 11000 Belgrade, Serbia Email: [email protected], corresponding author The contemporary industry is mainly based on fossil fuels to be exhausted in near future. It causes environment pollution and greenhouse effect. During the last century the CO2 concentration increased 20%, raising average temperature on Earth. It means undesirable climate changes, biodiversity disorder and natural disasters. The development of alternative power sources is needed. United Nations had recognized problem and global actions have already taken. European Union established main targets until 2030- Climate and Energy Package. The Paris Agreement (2015) adopted by 196 Parties from all over the world facilitated low-carbon solutions. Zero-carbon solutions are increasing in economy, especially the power and transport sectors. ˝The global climate fight will be won or lost in this crucial decade – on our watch. So let’s fight together– and let's win˝ (A. Guterres, UN General Secretary-November 2022). Thus, development of hydrogen production and fuel cells as zero-emission technologies is needed, to achieve sustainability and circular economy. Hydrogen is high efficiency and environmental friendly fuel. It is produced by water electrolysis, industrial procedure processed in alkaline solution, at 80oC. The main disadvantage is still high energy consumption (~ 5kWh m-3 H2). The hydrogen fuel is used in fuel cells, while oxidative agent is oxygen from air. Many researchers' efforts were done to make progress in this area during past decades. State-of-the-art catalysts are noble metals (carbon supported Platinum) – still expensive for large-scale commercial use. In this research novel solutions for fuel cells catalysts based on low loading precious metals were investigated. Higher efficiency and durability were achieved if compared to commercial Pt/C. Comparative study on Platinum and Palladium based catalysts was presented. Challenges and perspectives were discussed in terms of technological, social and financial issues. Trading and prices of noble metals were discussed, as well. Keywords: Renewable energy; Sustainable economic development; Hydrogen production; Fuel cells;, Zero-emission

Green Hydrogen Energy Based Economy to Decrease Climate Changes for Environmental Friendly-Sustainable Development

Green Hydrogen Energy Based Economy to Decrease Climate Changes for Environmental Friendly-Sustainable Development Nevenka R. Elrzovic University of Belgrade, Institute for Multidisciplinary Research, Center of Excellence for Green Technologies, Kneza Viseslava 1, 11000 Belgrade, Serbia, [email protected] Abstract: Intensive fossil fuel application leads to the growing environment pollution, causing the "greenhouse effect". During the 20th century the CO2 concentration increased about 20%, being the main reason for average temperature increase on Earth. This fact has already caused undesirable climate changes. United Nations has recognized environment pollution effects and global actions have already been taken. From Stockholm conference held in 1972 to COP 2022, United Nations announced several declarations to stabilize gas emission and decrease greenhouse effect. European Union has established main targets until 2030, in the frame of Climate and Energy Package, to increase alternative power sources usage and save environment. Thus, the further development of green hydrogen production and fuel cells catalysts as environmental friendly-green technologies are extremely desirable, to achieve sustainable economic development. Hydrogen – high efficiency and environmental friendly fuel, produced by water electrolysis is used in low temperature fuel cells, while oxidative agent is oxygen from air. In this work novel nanostructured materials with noble metal nanoparticles deposited onto ceramics based supports have been investigated as the catalysts for fuel cells, promising alternative power sources. Several ceramic supports were developed - Ti, Sn and W based oxides, doped by Ru or Nb to improve conductivity. Physical-chemical and electrochemical characterization of these novel materials confirmed higher efficiency and long term stability to decrease the costs and increase life time of fuel cells acceptable for commercial application. Biography: Dr Nevenka R. Elezovic completed her PhD in 2005, from University of Belgrade. She is currently Research Professor at the Institute for Multidisciplinary Research, University of Belgrade. Her research interests: Nanostructured materials and alloys for low temperature fuel cells and water electrolysis applications – environmental friendly green energy production. Since 2013 she has been serving as national representative of Serbia and member of the European board in European Academy of Surface Technology: http://www.east-site.net. She has published more than 50 papers in high impact peer reviewed international journals and more than 70 conference papers. Web page: http://www.imsi.bg.ac.rs/en/researchers/nevenka-r-elezovic Details of the Presenting Author: Nevenka R. Elezovic: [email protected] [email protected] Serbia: Presentation Category: Oral-Keynote lecture Recent Photograph: (High Resolution

Electrodeposited Co-Ru alloys at Ti2AlC suport as the catalysts for hydrogen production by water electrolysis towards sustainable economic development

Electrodeposited Co-Ru alloys at Ti2AlC suport as the catalysts for hydrogen production by water electrolysis towards sustainable economic development Nevenka Elezovic1*, D. Kutyla2, M. Krstajić Pajić3, U. Lačnjevac1, P. Zabinski2 1*University of Belgrade, Institute for Multidisciplinary Research, Kneza Viseslava 1, 11000 Belgrade, Serbia, *invited-presenting author – [email protected] 2 Faculty of Non-Ferrous Metals, AGH University of Science and Technology, Mickiewicza Ave. 30, 30-059 Krakow, Poland; 3 University of Belgrade, Faculty of Technology and Metallurgy, 11000 Belgrade, Serbia; Abstract Cobalt-ruthenium alloys were electrochemically deposited at Ti2AlC suport from hloride based acid electrolyte. Thin layers of Co-Ru were obtained by potentiostatic electrodeposition in the potential range of -0.6 V to -1.0 V vs SCE. The chemical composition and physical-chemical characterization have been performed by X-ray Fluorescence spectroscopy (XRF), X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM-EDS). It was found that increasing of Co content in the alloy led to gradual shift of the crystalline structure from HCP to FCC Co-Ru solid solution. The electrochemical characterization of the catalysts was done by linear sweep voltammetry, cyclic voltammetry and electrochemical impedance spectroscopy in alkaline electrolyte. The optimal conditions for deposition of nanocrystalline Co-Ru alloys with superior activity for hydrogen evolution were discussed in terms of activity and stability, as well as commercial acceptable costs for the catalysts production. Acknowledgements: This work was supported by the Ministry of Science and Technological Development Republic of Serbia (Contract No. 451-03-68/2023-14/200053 and Contract No. 451-03-68/2023-14/200135). The authors would like to thank Prof. M. Barsoum, Drexel University–Philadelphia USA for Ti2AlC preparation. Keywords: Electrodeposition; Co– Ru alloys; MAX phases; Hydrogen Renewable Energy; Water splitting; Biography Dr Nevenka R. Elezovic completed her PhD in 2005, from University of Belgrade. She is currently Research Professor at the Institute for Multidisciplinary Research, University of Belgrade. Her research interests include: Nanostructured materials and alloys for low temperature fuel cells and water electrolysis application - green energy production. Since 2013 she has been serving as national representative of Serbia and member of the European board in European Academy of Surface Technology: http://www.east-site.net. She has published more than 40 papers in high impact peer reviewed journals of eminent Publishers such as Elsevier, Royal Society of Chemistry, Springer, The Electrochemical Society and more than 70 conference papers. She has been serving as a reviewer for: Energy and Environmental Science, Applied Materials and Interfaces, Journal of Materials Chemistry A, Electrochimica Acta, Applied Catalysis B: Environmental, Journal of the Electrochemical Society, International Journal of Hydrogen Energy, as well as adjudicative (senior) reviewer for Energy and Environmental Science. She has given numerous invited lectures at the International conferences, recently at International Summit on Conventional and Sustainable Energies, 2018 Orlando, Florida, USA; Global Experts Meeting in Green Energy, 2019, Rome, Italy; Materials, the Building Block for the Future 3rd AAAFM-UCLA, 2021 Los Angeles USA; Euro-Global Climate Change conference, 2022, Paris, France. Web page: http://www.imsi.bg.ac.rs/en/researchers/nevenka-r-elezovi

Platinum layers on MAX phases based supports as advanced materials for low temperature fuel cells application

Platinum layers on MAX phases based supports as advanced materials for low temperature fuel cells application NEVENKA R. ELEZOVIC* *University of Belgrade - Institute for Multidisciplinary Research, Kneza Viseslava 1, 11030 Belgrade, Serbia Proton exchange membrane fuel cells (PEMFCs) are considered as promising future environmental friendly power sources. However, before the commercialization some important issues have to be resolved. MAX phase materials, such as Ti2AlC or (Nb-Ti)2AlC have been considered as perspective materials for variety of applications. These materials demonstrated high chemical and corrosion stability, high conductivity – close to metals′ one, as well as excellent stability in a wide potential range when used for electrochemical systems in water solutions. Moreover, commercialization was achieved at a very reasonable price. Thus, above mentioned materials could be promising alternative for catalyst supports in PEMFCs if compared to state-of-the-art carbon based materials. On the other hand, platinum is considered as the best catalyst for both anode and cathode reactions taking place in PEMFCs: hydrogen oxidation and oxygen reduction, especially in acid solutions. Having in mind the high cost and scarcity of Pt, deposition of ultrathin Pt layers on Max phases could be of great practical importance. In this research a facile and cost effective electrochemical method for successful deposition of thin Pt films (up to 10 monolayers) onto Ti2AlC and (Nb-Ti)2AlC substrate was referred. The obtained catalysts were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscpopy (EDS), and X-ray photoelectron spectroscopy (XPS). The oxygen reduction and hydrogen oxidation reactions were investigated by linear sweep voltammetry at rotating disc electrode (RDE). The results confirmed high activity and excellent stability in comparison to commercial carbon based Pt catalyst. Challenges and perspectives of these novel materials for green energy application have been discussed. Acknowledgements: This work was financially supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Contract No. 451-03-68/2022-14/200053. The authors would like to thank Prof. M. Barsoum, Drexel University Philadelphia, PA 19104 USA, for Max phase substrates preparation

MAX phases as the catalysts support materials for green energy related applications

MAX phases as the catalysts support materials for green energy related applications Nevenka R. Elezovic University of Belgrade-Institute for Multidisciplinary Research, Center of Excellence for Green Technologies, Kneza Viseslava 1, 11000 Belgrade, Serbia *Corresponding Author E-mail: [email protected] ABSTRACT MAX phases – specific materials of general formula Mn+1AXn, (MAX) where n = 1 to 4, where M is early transition metal, A is element from the group of Al, Si or P and X is carbon or nitrogen, have attracted great attention in materials science, especially as high performance supports for noble metals group catalysts intended to be used for hydrogen production by water electrolysis, as well as for fuel cells reactions. These materials demonstrated good mechanical properties, high conductivity, high chemical and corrosion stability, especially in the potential range from hydrogen to oxygen evolution that is of great interest for low temperature fuel cells reactions. In this research ultra- low loading platinum layers were deposited onto Ti2AlC and (Nb-Ti)2AlC MAX phases supports and characterized as the catalysts for anode (hydrogen oxidation) and cathode (oxygen reduction) reactions for low temperature fuel cells. Physical-chemical characterization was performed by: Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS), Focus-Ion Beam High Resolution Transmission Electron Microscopy (FIB-HRTEM). The electrochemical characterization for both anode and cathode reactions was done by cyclic voltammetry and linear sweep voltammetry and very good activities were confirmed in comparison to carbon supported commercial catalysts. It should be emphasized that progress beyond state of the art was made in terms of lower Pt loading - being only 18.3 µg cm-2 (for HOR the state of the art is ≈ 50 µg cm-2, while for ORR 200 -400 µg cm-2). These novel catalysts exhibited high durability according to US DOE standardized tests, as well. It is worthy to mention that the support materials are low cost and electrodeposition, as well. Acknowledgements: This work was financially supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Contract No. Contract No. 451-03-68/2022-14/200053). The author would like to thank Prof. M. Barsoum, Drexel University – Philadelphia PA 1 USA for preparation of MAX phases based substrates. Keywords: Fuel cells; MAX phases; ORR and HOR catalysts; low Pt loading layers; Biography: Dr Nevenka R. Elezovic completed her PhD in 2005, from University of Belgrade. She is currently Research Professor at the Institute for Multidisciplinary Research, University of Belgrade. Her research interests include: Nanostructured materials and alloys for low temperature fuel cells and water electrolysis application - green energy production. Since 2013 she has been serving as representative of Serbia and member of the European board in European Academy of Surface Technology,http://www.east-site.net. She has published more than 40 papers in reputed peer reviewed journals of eminent Publishers such as Elsevier, Royal Society of Chemistry, The Electrochemical Society and more than 70 conference papers. She has been serving as a reviewer for: Energy and Environmental Science, Applied Materials and Interfaces, Journal of Materials Chemistry A, Electrochimica Acta, Applied Catalysis B: Environmental, RSC Advances, Journal of the Electrochemical Society, International Journal of Hydrogen Energy, as well as adjudicative (senior) reviewer for Energy and Environmental Science and Journal of Materials Chemistry A. She has given numerous invited lectures at the International conferences, recently at International Summit on Conventional and Sustainable Energies, March 30-31, 2018 Orlando, Florida, USA; Global Experts Meeting on Frontiers in Green Energy and Expo, October 14-16, 2019 Rome, Italy; Materials, the Building Block for the Future 3rd AAAFM-UCLA conference, August 18-20 2021 Los Angeles USA; Euro-Global Climate Change Conference, September 19-20, 2022 Paris, France

Electrodeposition and characterization of Fe-Mo alloys as cathodes for hydrogen evolution in the process of chlorate production

Fe-Mo alloys were electrodeposited from a pyrophosphate bath using a single diode rectified AC current. Their composition and morphology were investigated by SEM, optical microscopy and EDS, in order to determine the influence of the deposition conditions on the morphology and composition of these alloys. It was shown that the electrodeposition parameters, such as: chemical bath composition and current density, influenced both the composition of the Fe Mo alloys and the current efficiency for their deposition, while the micro and macro-morphology did not change significantly with changing conditions of alloy electrodeposition. It was found that the electrodeposited Fe Mo alloys possessed a 0.15 V to 0.30 V lower overvoltage than mild steel for hydrogen evolution in ail electrolyte commonly used in commercial chlorate production, depending on the alloy composition, i.e., the conditions of alloy electrodeposition

Kinetics of the Hydrogen Oxidation on Pt Modified Moox Nano-Sized Catalyst in the Presence of Carbon Monoxide

Poster presented at the 11th Conference of the Materials Research Society of Serbia - YUCOMAT 2009, Herceg Novi, Montenegro, August 31 – September 4, 2009

Kinetics of the hydrogen oxidation on pt modified MoOx nano-sized catalyst in the presence of carbon monoxide

Due to the importance of the HOR in fuel-cells technology, various Pt-based catalysts have been examined from the viewpoint of immunity of the electrocatalysis of the HOR from CO-poisoning of the anode catalysts. An appreciable improvement of the CO tolerance has been found at Pt with adatoms such as Ru, Sn [1,2], Pt-M (M=Ru, Rh, Os, W Sn) [3-5] based alloys, and Pt with oxides (RuOxHy) [6]. In the present work, the electrocatalytic of home made highly dispersed nano-sized MoOx-Pt/C catalysts prepared by the polyole method combined by MoOx post-deposition was investigated in the presence of CO, in 0.5 moldm-3 HClO4 solution. The partial pressure of CO in CO/H2 gas mixture was 100 ppm. Carbon monoxide was adsorbed on the RDE for various time interval with keeping the potential at 0.05 V (RHE). The coverage of CO was determined by applying the first potential sweep (from 0.04 to 1.20 V), in N2 saturated solution at potential scan rate of 0.1 Vs-1 and compared it with the sweep on the clean electrode, by measuring the decrease in the hydrogen desorption charge, ΔQH. MoOx(20%)Pt/C catalyst exhibits an excellent CO tolerance, as it was found that the reduction in kinetic current, Ik, is negligible even at ΘCO = 0.46. It was found for this catalyst too, that the CO adsorption rate was much slower than that of Pt and the Pt sites for HOR were not so rigidly blocked by adsorbed CO partially due to its enhanced mobility, resulting from their modified electronic structure of surface Pt sites. Voltammetric studies suggest that an excellent CO tolerance of this catalyst could be also result of the oxidation of adsorbed CO to CO2 by oxophilic MoOx species at low overpotentials by a redox-mediated mechanism.Poster: [https://hdl.handle.net/21.15107/rcub_dais_266

Corrected accelerated service life test of electrodeposited NiSn alloys and Ni as cathodes for industrial alkaline water electrolysis

The "corrected accelerated service life test for hydrogen evolution reaction" (CASLT-HER), designed for application of certain electrode materials as cathodes in the cell for alkaline water electrolysis in 30 % KOH at 80 degrees C, was performed at electrodeposited NiSn alloy and Ni 40 mesh electrodes. The Ni 40 mesh was slightly etched, while the NiSn alloy coating was electro-deposited from the bath containing pyrophosphate, glycine, SnCl2 and NiCl2 onto Ni 40 mesh to the thickness of approximately 40 mu m. It is shown that the NiSn cathode possess from maximum 0.77 V to minimum 0.30 V better over-potential than the Ni 40 mesh electrode during the 5 years of their exploitation at the conditions of industrial alkaline water electrolysis. It is also shown that both electrodes should be held at j = -0.3 A cm(-2) for at least 5 h in order to establish stable overpotential response. The limiting overpotential values for applying cyclic voltammetry (CVs, to mimic "polarity inversion") should be determined in a separate experiment before the CASLT-HER and should be adjusted during the application of CVs

Platinum Nanocatalysts at Titanium Oxide Based Supports for Low Temperature Fuel Cell Applications

A comparative study on catalytic activity of platinum nanoparticles on different titanium oxide supports for proton exchange membrane fuel cells reactions was performed. Non stoichiometric titanium oxides – Ebonex, niobium doped titanium oxide and ruthenium doped titanium oxide were applied as the supporting materials. Platinum nanocatalysts (20% Pt) on different support were synthesized by impregnation or borohydride reduction method. Synthesized supports and catalyst were characterized by BET (Brunauer, Emmett, Teller), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Homogenous Pt nanoparticles distribution over the niobium and ruthenium doped TiO2 support, without pronounced particle agglomeration was confirmed by HRTEM technique. The average Pt particle size was 3 nm and 5.4 nm for Pt at niobium doped TiO2 and ruthenium doped TiO2, respectively. However, it was not possible to determine accurately average Pt particle size at Ebonex support, due to the non-uniform distribution of the Pt nanoparticles. Electrochemically active Pt surface area of the catalysts was determined by integration of the cyclic voltammetry curve in the potential region of underpotential deposition of hydrogen, after double layer charge correction, taking into account the reference value of 210 μC cm-2 for full monolayer coverage. Kinetics of the oxygen reduction reaction at Pt nanocatalysts on different titanium based supports was studied by cyclic voltammetry and linear sweep voltammetry at rotating gold disc electrode. Two different Tafel slopes at Pt catalysts on niobium and ruthenium doped supports were observed: one close to 60 mV dec-1 in low current density region, and other ~120 mV dec-1 in higher current densities region. Only at Ebonex based support one single Tafel slope (~ 106 mV dec-1) was observed. The specific activities for oxygen reduction, expressed in terms of kinetic current densities per electrochemically Pt active surface area, as well as per mass of Pt loaded, at the constant potential of practical interest (0.85 V and 0.90 V vs RHE, where the mass transport contribution current can be neglected), were compared to carbon supported one, with the same Pt loading. Stability tests, by repetitive cycling from 0.03V to high anodic potentials (up to 1.4 V vs RHE) were performed. The advantages of carbon free supports application in terms of stability, durability and life time of the catalysts were discussed