TY  - JOUR
AU  - Kokunešoski, Maja
AU  - Stanković, Miroslav
AU  - Vuković, Marina
AU  - Majstorović, Jelena
AU  - Šaponjić, Đorđe
AU  - Ilić, Svetlana
AU  - Šaponjić, Aleksandra
PY  - 2020
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/5222
AB  - Macroporous silica ceramic was obtained using clay and diatomite. Boric acid as a low-cost additive in the amount of 1 wt% was used. These porous materials were obtained at low forming pressure (40-80 MPa) and lower sintering temperature (850-1300 ºC) for 4h in air. The influence of boric acid, forming pressure, and sintering temperature on the microstructure, porosity parameters, and mechanical properties of obtained porous monoliths were investigated. As-received and the modified samples were characterized by X-ray diffraction, FTIR, SEM, and mercury porosimetry measurements. As for modified clay and diatomite, they were pressed at 60 MPa and then sintered at 1150 ºC, obtaining porosities of about 10 % and 60 %, respectively. Both of the analyzed samples had the pore diameter in the range of macroporous materials. The pore diameters of clay samples are ranging from 0.1-10 μm, whereas the pore diameter of diatomite samples was slightly lower with values ranging from 0.05-5 μm. Modified diatomite samples have a lower Young modulus in comparison to modified clay samples.
T2  - Science of Sintering
T1  - Macroporous monoliths based оn natural mineral sources, clay аnd diatomite
VL  - 52
IS  - 3
SP  - 339
EP  - 348
DO  - 10.2298/SOS2003339K
ER  - 

@article{
author = "Kokunešoski, Maja and Stanković, Miroslav and Vuković, Marina and Majstorović, Jelena and Šaponjić, Đorđe and Ilić, Svetlana and Šaponjić, Aleksandra",
year = "2020",
abstract = "Macroporous silica ceramic was obtained using clay and diatomite. Boric acid as a low-cost additive in the amount of 1 wt% was used. These porous materials were obtained at low forming pressure (40-80 MPa) and lower sintering temperature (850-1300 ºC) for 4h in air. The influence of boric acid, forming pressure, and sintering temperature on the microstructure, porosity parameters, and mechanical properties of obtained porous monoliths were investigated. As-received and the modified samples were characterized by X-ray diffraction, FTIR, SEM, and mercury porosimetry measurements. As for modified clay and diatomite, they were pressed at 60 MPa and then sintered at 1150 ºC, obtaining porosities of about 10 % and 60 %, respectively. Both of the analyzed samples had the pore diameter in the range of macroporous materials. The pore diameters of clay samples are ranging from 0.1-10 μm, whereas the pore diameter of diatomite samples was slightly lower with values ranging from 0.05-5 μm. Modified diatomite samples have a lower Young modulus in comparison to modified clay samples.",
journal = "Science of Sintering",
title = "Macroporous monoliths based оn natural mineral sources, clay аnd diatomite",
volume = "52",
number = "3",
pages = "339-348",
doi = "10.2298/SOS2003339K"
}

Kokunešoski, M., Stanković, M., Vuković, M., Majstorović, J., Šaponjić, Đ., Ilić, S.,& Šaponjić, A.. (2020). Macroporous monoliths based оn natural mineral sources, clay аnd diatomite. in Science of Sintering, 52(3), 339-348.
https://doi.org/10.2298/SOS2003339K

Kokunešoski M, Stanković M, Vuković M, Majstorović J, Šaponjić Đ, Ilić S, Šaponjić A. Macroporous monoliths based оn natural mineral sources, clay аnd diatomite. in Science of Sintering. 2020;52(3):339-348.
doi:10.2298/SOS2003339K .

Kokunešoski, Maja, Stanković, Miroslav, Vuković, Marina, Majstorović, Jelena, Šaponjić, Đorđe, Ilić, Svetlana, Šaponjić, Aleksandra, "Macroporous monoliths based оn natural mineral sources, clay аnd diatomite" in Science of Sintering, 52, no. 3 (2020):339-348,
https://doi.org/10.2298/SOS2003339K . .

TY  - JOUR
AU  - Šaponjić, Aleksandra
AU  - Šaponjić, Đorđe
AU  - Perović, Ivana
AU  - Vuković, Marina
AU  - Nikolić, Vladimir
AU  - Kaninski, Milica Marčeta
AU  - Kokunešoski, Maja
PY  - 2019
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/3700
AB  - Co-Mo carbides were prepared by impregnation with aqueous solution of metal salts and sucrose into ordered mesoporous SBA-15 silica template using carbothermal hydrogen reduction. Bimetallic Co-Mo carbide obtained by using carbothermal hydrogen reduction of Co-Mo precursors is formed when the Co-Mo molar ratio is 1.0. The obtained samples were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. Electrochemical characterization of obtained materials wеre performed by cyclic voltammetry in acid solution.
PB  - International Institute for the Science of Sintering (IISS)
T2  - Science of Sintering
T1  - Synthesis and characterization of co-mo bimetallic carbides
VL  - 51
IS  - 3
SP  - 319
EP  - 326
DO  - 10.2298/SOS1903319S
ER  - 

@article{
author = "Šaponjić, Aleksandra and Šaponjić, Đorđe and Perović, Ivana and Vuković, Marina and Nikolić, Vladimir and Kaninski, Milica Marčeta and Kokunešoski, Maja",
year = "2019",
abstract = "Co-Mo carbides were prepared by impregnation with aqueous solution of metal salts and sucrose into ordered mesoporous SBA-15 silica template using carbothermal hydrogen reduction. Bimetallic Co-Mo carbide obtained by using carbothermal hydrogen reduction of Co-Mo precursors is formed when the Co-Mo molar ratio is 1.0. The obtained samples were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. Electrochemical characterization of obtained materials wеre performed by cyclic voltammetry in acid solution.",
publisher = "International Institute for the Science of Sintering (IISS)",
journal = "Science of Sintering",
title = "Synthesis and characterization of co-mo bimetallic carbides",
volume = "51",
number = "3",
pages = "319-326",
doi = "10.2298/SOS1903319S"
}

Šaponjić, A., Šaponjić, Đ., Perović, I., Vuković, M., Nikolić, V., Kaninski, M. M.,& Kokunešoski, M.. (2019). Synthesis and characterization of co-mo bimetallic carbides. in Science of Sintering
International Institute for the Science of Sintering (IISS)., 51(3), 319-326.
https://doi.org/10.2298/SOS1903319S

Šaponjić A, Šaponjić Đ, Perović I, Vuković M, Nikolić V, Kaninski MM, Kokunešoski M. Synthesis and characterization of co-mo bimetallic carbides. in Science of Sintering. 2019;51(3):319-326.
doi:10.2298/SOS1903319S .

Šaponjić, Aleksandra, Šaponjić, Đorđe, Perović, Ivana, Vuković, Marina, Nikolić, Vladimir, Kaninski, Milica Marčeta, Kokunešoski, Maja, "Synthesis and characterization of co-mo bimetallic carbides" in Science of Sintering, 51, no. 3 (2019):319-326,
https://doi.org/10.2298/SOS1903319S . .

TY  - THES
AU  - Maksić, Aleksandar D.
PY  - 2018
UR  - http://eteze.bg.ac.rs/application/showtheses?thesesId=5718
UR  - https://fedorabg.bg.ac.rs/fedora/get/o:17491/bdef:Content/download
UR  - http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=50004751
UR  - http://nardus.mpn.gov.rs/123456789/9355
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2761
AB  - Kao odgovor rastućim energetskim potrebama modernog društva i potrebi zarešavanjem ekoloških problema, naučna i tehnološka istraživanja su fokusirana kapronalaženju čistih i efikasnih izvora energije u cilju smanjenja emisije CO2 koje potičeod sagorevanja fosilnih goriva i izbegavanju eventualne energetske krize. Shodno tome,javlja se sve veće interesovanje ka razvoju novih, jeftinijih i ekoloških sistema zakonverziju i skladištenje energije. Od svih sistema za konverziju energije najvišeobećavaju gorivne ćelije koje kao gorivo koriste male organske molekule kao što suvodonik, metanol i etanol u kojima se prilično efikasno vrši direktna konverzijahemijske u električnu energiju uz vrlo nisku emisiju zagađivača.Gorivne ćelije koje koriste alkohol kao gorivo (DAFCs – Direct Alcohol FuelCells) kao izvor energije su naročito pogodne za korišćenje, kako u prevoznimsredstvima, tako i u malim elektronskim uređajima, zbog njihovog relatvno brzog startai niske radne temperature. Uprkos obimnim istraživanjima, široka upotreba alkoholnihgorivnih ćelija još uvek je ograničena zbog njihove cene, relativno niske energije kao inezadovoljavajuće gustine snage. U cilju rešavanja ovih problema, istraživanja suusmerena ka boljem razumevanju mehanizama elektrohemijskih reakcija koje sedešavaju u gorivnim ćelijama i razvoju visoko aktivnih elektrodnih katalizatora da bi sepostigla bolja efikasnost, a samim tim i smanjenje cene.U ovom proučavanju, ispitivane su reakcije elektrooksidacije metanola ietanola u alkalnoj sredini na bimetalnim elektrodama, dobijenim spontanimdeponovanjem nanoostrva paladijuma, rodijuma i rutenijuma uz pokrivenost manju odmonosloja na površinama polikristalnih elektroda platine i paladijuma. Ex-situkarakterizacija dobijenih Pd/Pt(poly), Rh/Pd(poly) i Ru/Pd(poly) nanostruktura jevršena mikroskopijom atomskih sila (AFM), elipsometrijskom spektroskopijom irendgenskom fotoelektronskom sprektroskopijom (XPS). In-situ karakterizacijadobijenih elektroda kao i proučavanje reakcije elektrooksidacije metanola i etanolavršene su cikličnom voltametrijom u 0,1 M KOH-u. Bimetalne površine modifikovanihelektroda su pokazale bolju katalitičku aktivnost za reakcije oksidacije metanola ietanola u alkalnoj sredini...
AB  - In response to the energy needs of modern society and emerging ecologicalconcerns, scientific and technological researches have focused on the development ofclean, efficient power sources to diminish CO2 emission coming from combustion offuels and to avoid energy crisis. Consequently, development of novel, low-cost, andenvironment friendly energy conversion and storage systems has raised significantinterest. Among various energy conversion and storage systems, one of the mostencouraging is fuel cells using small organic molecules such as methanol and ethanolsince they convert chemical energy directly into electrical energy with high efficiencyand low pollutant emissions.Direct alcohol fuel cells (DAFCs) are an ideal fuel cell system for applicationsin electric vehicles and electronic portable devices due to their relatively quick start-upand low operating temperature. Despite extensive research, the wide commercial use ofDAFCs is hampered by their high cost, relatively low energy and power densities. Inorder to address these problems, researches are focused to better understanding of themechanism of electrochemical reactions taking place in fuel cells and development ofhighly active electrode catalysts to attain high efficiency of DAFCs, and subsequentlylowering the cost.In this study, bimetallic electrodes prepared by Pd, Rh and Ru nanoislandsspontaneously deposited on polycrystalline platinum, Pt(poly), and polycrystallinepalladium, Pd(poly), at submonolayer coverage were explored for methanol andethanol oxidation in alkaline media.Characterization of obtained Pd/Pt(poly), Rh/Pd(poly) and Ru/Pd(poly)nanostructures was performed ex situ by AFM imaging, spectroscopic ellipsometry andby X-ray photoelectron spectroscopy. In situ characterization of the obtained electrodesand subsequent methanol and ethanol oxidation measurements were performed bycyclic voltammetry in 0,1 M KOH. Bimetallic surfaces of modified electrodes exhibitedthe highest catalytic activity for methanol and ethanol oxidation in alkaline media...
PB  - Универзитет у Београду, Хемијски факултет
T2  - Универзитет у Београду
T1  - Elektrokataliza oksidacije malih organskih molekula na elektrodama platine i paladijuma modifikovanim nanoostrvima paladijuma, rodijuma i rutenijuma-značaj za primenu u gorivnim ćelijama
UR  - https://hdl.handle.net/21.15107/rcub_nardus_9355
ER  - 

@phdthesis{
author = "Maksić, Aleksandar D.",
year = "2018",
abstract = "Kao odgovor rastućim energetskim potrebama modernog društva i potrebi zarešavanjem ekoloških problema, naučna i tehnološka istraživanja su fokusirana kapronalaženju čistih i efikasnih izvora energije u cilju smanjenja emisije CO2 koje potičeod sagorevanja fosilnih goriva i izbegavanju eventualne energetske krize. Shodno tome,javlja se sve veće interesovanje ka razvoju novih, jeftinijih i ekoloških sistema zakonverziju i skladištenje energije. Od svih sistema za konverziju energije najvišeobećavaju gorivne ćelije koje kao gorivo koriste male organske molekule kao što suvodonik, metanol i etanol u kojima se prilično efikasno vrši direktna konverzijahemijske u električnu energiju uz vrlo nisku emisiju zagađivača.Gorivne ćelije koje koriste alkohol kao gorivo (DAFCs – Direct Alcohol FuelCells) kao izvor energije su naročito pogodne za korišćenje, kako u prevoznimsredstvima, tako i u malim elektronskim uređajima, zbog njihovog relatvno brzog startai niske radne temperature. Uprkos obimnim istraživanjima, široka upotreba alkoholnihgorivnih ćelija još uvek je ograničena zbog njihove cene, relativno niske energije kao inezadovoljavajuće gustine snage. U cilju rešavanja ovih problema, istraživanja suusmerena ka boljem razumevanju mehanizama elektrohemijskih reakcija koje sedešavaju u gorivnim ćelijama i razvoju visoko aktivnih elektrodnih katalizatora da bi sepostigla bolja efikasnost, a samim tim i smanjenje cene.U ovom proučavanju, ispitivane su reakcije elektrooksidacije metanola ietanola u alkalnoj sredini na bimetalnim elektrodama, dobijenim spontanimdeponovanjem nanoostrva paladijuma, rodijuma i rutenijuma uz pokrivenost manju odmonosloja na površinama polikristalnih elektroda platine i paladijuma. Ex-situkarakterizacija dobijenih Pd/Pt(poly), Rh/Pd(poly) i Ru/Pd(poly) nanostruktura jevršena mikroskopijom atomskih sila (AFM), elipsometrijskom spektroskopijom irendgenskom fotoelektronskom sprektroskopijom (XPS). In-situ karakterizacijadobijenih elektroda kao i proučavanje reakcije elektrooksidacije metanola i etanolavršene su cikličnom voltametrijom u 0,1 M KOH-u. Bimetalne površine modifikovanihelektroda su pokazale bolju katalitičku aktivnost za reakcije oksidacije metanola ietanola u alkalnoj sredini..., In response to the energy needs of modern society and emerging ecologicalconcerns, scientific and technological researches have focused on the development ofclean, efficient power sources to diminish CO2 emission coming from combustion offuels and to avoid energy crisis. Consequently, development of novel, low-cost, andenvironment friendly energy conversion and storage systems has raised significantinterest. Among various energy conversion and storage systems, one of the mostencouraging is fuel cells using small organic molecules such as methanol and ethanolsince they convert chemical energy directly into electrical energy with high efficiencyand low pollutant emissions.Direct alcohol fuel cells (DAFCs) are an ideal fuel cell system for applicationsin electric vehicles and electronic portable devices due to their relatively quick start-upand low operating temperature. Despite extensive research, the wide commercial use ofDAFCs is hampered by their high cost, relatively low energy and power densities. Inorder to address these problems, researches are focused to better understanding of themechanism of electrochemical reactions taking place in fuel cells and development ofhighly active electrode catalysts to attain high efficiency of DAFCs, and subsequentlylowering the cost.In this study, bimetallic electrodes prepared by Pd, Rh and Ru nanoislandsspontaneously deposited on polycrystalline platinum, Pt(poly), and polycrystallinepalladium, Pd(poly), at submonolayer coverage were explored for methanol andethanol oxidation in alkaline media.Characterization of obtained Pd/Pt(poly), Rh/Pd(poly) and Ru/Pd(poly)nanostructures was performed ex situ by AFM imaging, spectroscopic ellipsometry andby X-ray photoelectron spectroscopy. In situ characterization of the obtained electrodesand subsequent methanol and ethanol oxidation measurements were performed bycyclic voltammetry in 0,1 M KOH. Bimetallic surfaces of modified electrodes exhibitedthe highest catalytic activity for methanol and ethanol oxidation in alkaline media...",
publisher = "Универзитет у Београду, Хемијски факултет",
journal = "Универзитет у Београду",
title = "Elektrokataliza oksidacije malih organskih molekula na elektrodama platine i paladijuma modifikovanim nanoostrvima paladijuma, rodijuma i rutenijuma-značaj za primenu u gorivnim ćelijama",
url = "https://hdl.handle.net/21.15107/rcub_nardus_9355"
}

Maksić, A. D.. (2018). Elektrokataliza oksidacije malih organskih molekula na elektrodama platine i paladijuma modifikovanim nanoostrvima paladijuma, rodijuma i rutenijuma-značaj za primenu u gorivnim ćelijama. in Универзитет у Београду
Универзитет у Београду, Хемијски факултет..
https://hdl.handle.net/21.15107/rcub_nardus_9355

Maksić AD. Elektrokataliza oksidacije malih organskih molekula na elektrodama platine i paladijuma modifikovanim nanoostrvima paladijuma, rodijuma i rutenijuma-značaj za primenu u gorivnim ćelijama. in Универзитет у Београду. 2018;.
https://hdl.handle.net/21.15107/rcub_nardus_9355 .

Maksić, Aleksandar D., "Elektrokataliza oksidacije malih organskih molekula na elektrodama platine i paladijuma modifikovanim nanoostrvima paladijuma, rodijuma i rutenijuma-značaj za primenu u gorivnim ćelijama" in Универзитет у Београду (2018),
https://hdl.handle.net/21.15107/rcub_nardus_9355 .

TY  - JOUR
AU  - Šaponjić, Aleksandra
AU  - Šaponjić, Đorđe
AU  - Nikolić, Violeta N.
AU  - Milošević, Maja
AU  - Marinović-Cincović, Milena
AU  - Gyoshev, Stanislav
AU  - Vuković, Marina
AU  - Kokunešoski, Maja
PY  - 2017
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/5225
AB  - Amorphous iron (III) oxide was obtained from clay, using ammonium hydroxide as a precipitating agent. Influence of freeze drying under vacuum, as a drying method, on particle size, chemical composition, and crystallinity of obtained iron (III) oxide powder was investigated. After freeze drying, precipitate was annealed in air at 500 C-o and 900 oC. X-ray diffraction, particle size analysis, scanning electron microscopy, energy dispersive spectrometry, Fourier transform infrared spectroscopy, thermogravimetric and differential thermal analysis were used to characterize obtained iron (III) oxide powder. All of three powders obtained by freeze drying and annealing, have low crystallinity and particles with irregular layered shape. Narrow particle size distribution was given by an average diameter value of around 50 mu m for all observed powders. Iron-bearing materials like a-Fe2O3 and gamma-Fe2O3 are obtained. Differential thermal analysis curve of obtained samples showed endothermic reaction at 620 oC which could be ascribed to phase transition from cubic form gamma- - GT alpha- Fe2O3. Thermal transformations of iron (III) oxide, obtained from clay as a natural source, is suitable to explore in the framework of materials chemistry, and opens the possibility to synthesize materials based on Fe2O3 with specific magnetic behavior.
T2  - Science of Sintering
T1  - Iron (III) Oxide Fabrication From Natural Clay With Reference to Phase Transformation gamma- - GT alpha- Fe2O3
VL  - 49
IS  - 2
SP  - 197
EP  - 205
DO  - 10.2298/SOS1702197S
ER  - 

@article{
author = "Šaponjić, Aleksandra and Šaponjić, Đorđe and Nikolić, Violeta N. and Milošević, Maja and Marinović-Cincović, Milena and Gyoshev, Stanislav and Vuković, Marina and Kokunešoski, Maja",
year = "2017",
abstract = "Amorphous iron (III) oxide was obtained from clay, using ammonium hydroxide as a precipitating agent. Influence of freeze drying under vacuum, as a drying method, on particle size, chemical composition, and crystallinity of obtained iron (III) oxide powder was investigated. After freeze drying, precipitate was annealed in air at 500 C-o and 900 oC. X-ray diffraction, particle size analysis, scanning electron microscopy, energy dispersive spectrometry, Fourier transform infrared spectroscopy, thermogravimetric and differential thermal analysis were used to characterize obtained iron (III) oxide powder. All of three powders obtained by freeze drying and annealing, have low crystallinity and particles with irregular layered shape. Narrow particle size distribution was given by an average diameter value of around 50 mu m for all observed powders. Iron-bearing materials like a-Fe2O3 and gamma-Fe2O3 are obtained. Differential thermal analysis curve of obtained samples showed endothermic reaction at 620 oC which could be ascribed to phase transition from cubic form gamma- - GT alpha- Fe2O3. Thermal transformations of iron (III) oxide, obtained from clay as a natural source, is suitable to explore in the framework of materials chemistry, and opens the possibility to synthesize materials based on Fe2O3 with specific magnetic behavior.",
journal = "Science of Sintering",
title = "Iron (III) Oxide Fabrication From Natural Clay With Reference to Phase Transformation gamma- - GT alpha- Fe2O3",
volume = "49",
number = "2",
pages = "197-205",
doi = "10.2298/SOS1702197S"
}

Šaponjić, A., Šaponjić, Đ., Nikolić, V. N., Milošević, M., Marinović-Cincović, M., Gyoshev, S., Vuković, M.,& Kokunešoski, M.. (2017). Iron (III) Oxide Fabrication From Natural Clay With Reference to Phase Transformation gamma- - GT alpha- Fe2O3. in Science of Sintering, 49(2), 197-205.
https://doi.org/10.2298/SOS1702197S

Šaponjić A, Šaponjić Đ, Nikolić VN, Milošević M, Marinović-Cincović M, Gyoshev S, Vuković M, Kokunešoski M. Iron (III) Oxide Fabrication From Natural Clay With Reference to Phase Transformation gamma- - GT alpha- Fe2O3. in Science of Sintering. 2017;49(2):197-205.
doi:10.2298/SOS1702197S .

Šaponjić, Aleksandra, Šaponjić, Đorđe, Nikolić, Violeta N., Milošević, Maja, Marinović-Cincović, Milena, Gyoshev, Stanislav, Vuković, Marina, Kokunešoski, Maja, "Iron (III) Oxide Fabrication From Natural Clay With Reference to Phase Transformation gamma- - GT alpha- Fe2O3" in Science of Sintering, 49, no. 2 (2017):197-205,
https://doi.org/10.2298/SOS1702197S . .