TY  - JOUR
AU  - Elezovic, N. R.
AU  - Babić, Biljana M.
AU  - Gajic-Krstajic, Lj.
AU  - Ercius, P.
AU  - Radmilovíć, Velimir R.
AU  - Krstajic, N. V.
AU  - Vracar, Lj. M.
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4846
AB  - Platinum nanocatalyst at nano-tungsten carbide was synthesized, characterized and tested for oxygen reduction reaction (ORR) in 0.1 mol dm(-3) NaOH, at 25 degrees C. Tungsten-carbide islands on nano-tungsten particles (WC) was synthesized from gel prepared by using nanoparticles of WO3, previously produced from W-powder oxidized in H2O2. The support was porous material with high specific surface area (177 m(2)g(-1)). The WC supported Pt (10 wt.%) catalyst was prepared by borohydride reduction method. X-ray diffraction of the catalyst demonstrates successful reduction of Pt precursor to metallic form. STEM analysis of Pt/WC catalyst showed the existence of Pt particles lower than 2 nm in size, even the clusters of Pt atoms. Electrochemically active surface area of Pt was determined from adsorption/desorption charge of hydrogen atoms. Catalytic activity of the synthesized catalyst for ORR was studied by cyclic voltammetry and linear sweep voltammetry at rotating disk electrode. The onset potential on Pt/WC for ORR, comparing with Pt/Vulcan, was shifted to the positive potentials for about 150 mV. Pt/WC catalyst shows one Tafel slope of -0.105 V dec(-1), remarkable catalytic activity expressed either through the value of the current density per real surface area, or through the mass activity and excellent stability. (C) 2012 Elsevier Ltd. All rights reserved.
T2  - Electrochimica Acta
T1  - Pt supported on nano-tungsten carbide as a beneficial catalyst for the oxygen reduction reaction in alkaline solution
VL  - 69
SP  - 239
EP  - 246
DO  - 10.1016/j.electacta.2012.02.105
ER  - 

@article{
author = "Elezovic, N. R. and Babić, Biljana M. and Gajic-Krstajic, Lj. and Ercius, P. and Radmilovíć, Velimir R. and Krstajic, N. V. and Vracar, Lj. M.",
year = "2012",
abstract = "Platinum nanocatalyst at nano-tungsten carbide was synthesized, characterized and tested for oxygen reduction reaction (ORR) in 0.1 mol dm(-3) NaOH, at 25 degrees C. Tungsten-carbide islands on nano-tungsten particles (WC) was synthesized from gel prepared by using nanoparticles of WO3, previously produced from W-powder oxidized in H2O2. The support was porous material with high specific surface area (177 m(2)g(-1)). The WC supported Pt (10 wt.%) catalyst was prepared by borohydride reduction method. X-ray diffraction of the catalyst demonstrates successful reduction of Pt precursor to metallic form. STEM analysis of Pt/WC catalyst showed the existence of Pt particles lower than 2 nm in size, even the clusters of Pt atoms. Electrochemically active surface area of Pt was determined from adsorption/desorption charge of hydrogen atoms. Catalytic activity of the synthesized catalyst for ORR was studied by cyclic voltammetry and linear sweep voltammetry at rotating disk electrode. The onset potential on Pt/WC for ORR, comparing with Pt/Vulcan, was shifted to the positive potentials for about 150 mV. Pt/WC catalyst shows one Tafel slope of -0.105 V dec(-1), remarkable catalytic activity expressed either through the value of the current density per real surface area, or through the mass activity and excellent stability. (C) 2012 Elsevier Ltd. All rights reserved.",
journal = "Electrochimica Acta",
title = "Pt supported on nano-tungsten carbide as a beneficial catalyst for the oxygen reduction reaction in alkaline solution",
volume = "69",
pages = "239-246",
doi = "10.1016/j.electacta.2012.02.105"
}

Elezovic, N. R., Babić, B. M., Gajic-Krstajic, Lj., Ercius, P., Radmilovíć, V. R., Krstajic, N. V.,& Vracar, Lj. M.. (2012). Pt supported on nano-tungsten carbide as a beneficial catalyst for the oxygen reduction reaction in alkaline solution. in Electrochimica Acta, 69, 239-246.
https://doi.org/10.1016/j.electacta.2012.02.105

Elezovic NR, Babić BM, Gajic-Krstajic L, Ercius P, Radmilovíć VR, Krstajic NV, Vracar LM. Pt supported on nano-tungsten carbide as a beneficial catalyst for the oxygen reduction reaction in alkaline solution. in Electrochimica Acta. 2012;69:239-246.
doi:10.1016/j.electacta.2012.02.105 .

Elezovic, N. R., Babić, Biljana M., Gajic-Krstajic, Lj., Ercius, P., Radmilovíć, Velimir R., Krstajic, N. V., Vracar, Lj. M., "Pt supported on nano-tungsten carbide as a beneficial catalyst for the oxygen reduction reaction in alkaline solution" in Electrochimica Acta, 69 (2012):239-246,
https://doi.org/10.1016/j.electacta.2012.02.105 . .

TY  - JOUR
AU  - Elezovic, Nevenka R.
AU  - Babić, Biljana M.
AU  - Radmilović, Velimir
AU  - Gajic-Krstajic, Ljiljana M.
AU  - Krstajic, Nedeljko V.
AU  - Vracar, Ljiljana M.
PY  - 2011
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4475
AB  - The kinetics of the hydrogen oxidation reaction (HOR) was studied at Pt nanoparticles supported on niobia-doped titania (Pt/N-T). The catalyst support, with the composition of 0.05NbO(2.5-delta)-0.995TiO(2) (0 LT delta LT 1), was synthesized by a modified sol gel procedure and characterized by the BET and X-ray diffraction (XRD) techniques. The specific surface area of the support was found to be 70 m(2) g(-1). The XRD analysis revealed the presence of the anatase TiO(2) phase in the support powder. No peaks indicating the existence of Nb-compounds were detected. Pt/N-T nanocatalyst was synthesized by the borohydride reduction method. Transmission electron microscopy revealed a quite homogenous distribution of the Pt nanoparticles over the support, with a mean particle size of about 3 nm. The electrochemical active surface area of Pt of 42 +/- 14 m(2) g(-1) was determined by the cyclic voltammetry technique. The kinetics of the HOR was investigated by linear sweep voltammetry at a rotating disc electrode in 0.5 mol dm(-3) HClO(4) solution. The determined value of the Tafel slope of 35 mV dec(-1) and an exchange current density of 0.45 mA cm(-2) per real surface area of the Pt are in good accordance with those already reported in the literature for the HOR at polycrystalline Pt and Pt nanocatalysts in acid solutions. This new catalyst exhibited better activity for the HOR in comparison with Pt nanocatalyst supported on Vulcan (R) XC-72R high area carbon.
T2  - Journal of the Serbian Chemical Society
T1  - A novel platinum-based nanocatalyst at a niobia-doped titania support for the hydrogen oxidation reaction
VL  - 76
IS  - 8
SP  - 1139
EP  - 1152
DO  - 10.2298/JSC100823100E
ER  - 

@article{
author = "Elezovic, Nevenka R. and Babić, Biljana M. and Radmilović, Velimir and Gajic-Krstajic, Ljiljana M. and Krstajic, Nedeljko V. and Vracar, Ljiljana M.",
year = "2011",
abstract = "The kinetics of the hydrogen oxidation reaction (HOR) was studied at Pt nanoparticles supported on niobia-doped titania (Pt/N-T). The catalyst support, with the composition of 0.05NbO(2.5-delta)-0.995TiO(2) (0 LT delta LT 1), was synthesized by a modified sol gel procedure and characterized by the BET and X-ray diffraction (XRD) techniques. The specific surface area of the support was found to be 70 m(2) g(-1). The XRD analysis revealed the presence of the anatase TiO(2) phase in the support powder. No peaks indicating the existence of Nb-compounds were detected. Pt/N-T nanocatalyst was synthesized by the borohydride reduction method. Transmission electron microscopy revealed a quite homogenous distribution of the Pt nanoparticles over the support, with a mean particle size of about 3 nm. The electrochemical active surface area of Pt of 42 +/- 14 m(2) g(-1) was determined by the cyclic voltammetry technique. The kinetics of the HOR was investigated by linear sweep voltammetry at a rotating disc electrode in 0.5 mol dm(-3) HClO(4) solution. The determined value of the Tafel slope of 35 mV dec(-1) and an exchange current density of 0.45 mA cm(-2) per real surface area of the Pt are in good accordance with those already reported in the literature for the HOR at polycrystalline Pt and Pt nanocatalysts in acid solutions. This new catalyst exhibited better activity for the HOR in comparison with Pt nanocatalyst supported on Vulcan (R) XC-72R high area carbon.",
journal = "Journal of the Serbian Chemical Society",
title = "A novel platinum-based nanocatalyst at a niobia-doped titania support for the hydrogen oxidation reaction",
volume = "76",
number = "8",
pages = "1139-1152",
doi = "10.2298/JSC100823100E"
}

Elezovic, N. R., Babić, B. M., Radmilović, V., Gajic-Krstajic, L. M., Krstajic, N. V.,& Vracar, L. M.. (2011). A novel platinum-based nanocatalyst at a niobia-doped titania support for the hydrogen oxidation reaction. in Journal of the Serbian Chemical Society, 76(8), 1139-1152.
https://doi.org/10.2298/JSC100823100E

Elezovic NR, Babić BM, Radmilović V, Gajic-Krstajic LM, Krstajic NV, Vracar LM. A novel platinum-based nanocatalyst at a niobia-doped titania support for the hydrogen oxidation reaction. in Journal of the Serbian Chemical Society. 2011;76(8):1139-1152.
doi:10.2298/JSC100823100E .

Elezovic, Nevenka R., Babić, Biljana M., Radmilović, Velimir, Gajic-Krstajic, Ljiljana M., Krstajic, Nedeljko V., Vracar, Ljiljana M., "A novel platinum-based nanocatalyst at a niobia-doped titania support for the hydrogen oxidation reaction" in Journal of the Serbian Chemical Society, 76, no. 8 (2011):1139-1152,
https://doi.org/10.2298/JSC100823100E . .

TY  - JOUR
AU  - Elezovic, N. R.
AU  - Babić, Biljana M.
AU  - Gajic-Krstajic, Lj.
AU  - Radmilović, Velimir
AU  - Krstajic, N. V.
AU  - Vracar, L. J.
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3980
AB  - In order to point out the effect of the support to the catalyst for oxygen reduction reaction nano-crystalline Nb-doped TiO2 was synthesized through a modified sol-gel route procedure. The specific surface area of the support, S-BET, and pore size distribution, were calculated from the adsorption isotherms using the gravimetric McBain method. The support was characterized by X-ray diffraction (XRD) technique. The borohydride reduction method was used to prepare Nb-TiO2 supported Pt (20 wt.%) catalyst. The synthesized catalyst was analyzed by TEM technique. Finally, the catalytic activity of this new catalyst for oxygen reduction reaction was investigated in acid solution, in the absence and the presence of methanol, and its activity was compared towards the results on C/Pt catalysts. Kinetic analysis reveals that the oxygen reduction reaction on Nb-TiO2/Pt catalyst follows four-electron process leading to water, as in the case of C/Pt electrode, but the Tafel plots normalized to the electrochemically active surface area show very remarkable enhancement in activity of Nb-TiO2/Pt expressed through the value of the current density at the constant potential. Moreover, Nb-TiO2/Pt catalyst exhibits higher methanol tolerance during the oxygen reduction reaction than the C/Pt catalyst. The enhancement in the activity of Nb-TiO2/Pt is consequence of both: the interactions of Pt nanoparticles with the support and the energy shift of the surface d-states with respect to the Fermi level what changes the surface reactivity. (C) 2010 Elsevier B.V. All rights reserved.
T2  - Journal of Power Sources
T1  - Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction
VL  - 195
IS  - 13
SP  - 3961
EP  - 3968
DO  - 10.1016/j.jpowsour.2010.01.035
ER  - 

@article{
author = "Elezovic, N. R. and Babić, Biljana M. and Gajic-Krstajic, Lj. and Radmilović, Velimir and Krstajic, N. V. and Vracar, L. J.",
year = "2010",
abstract = "In order to point out the effect of the support to the catalyst for oxygen reduction reaction nano-crystalline Nb-doped TiO2 was synthesized through a modified sol-gel route procedure. The specific surface area of the support, S-BET, and pore size distribution, were calculated from the adsorption isotherms using the gravimetric McBain method. The support was characterized by X-ray diffraction (XRD) technique. The borohydride reduction method was used to prepare Nb-TiO2 supported Pt (20 wt.%) catalyst. The synthesized catalyst was analyzed by TEM technique. Finally, the catalytic activity of this new catalyst for oxygen reduction reaction was investigated in acid solution, in the absence and the presence of methanol, and its activity was compared towards the results on C/Pt catalysts. Kinetic analysis reveals that the oxygen reduction reaction on Nb-TiO2/Pt catalyst follows four-electron process leading to water, as in the case of C/Pt electrode, but the Tafel plots normalized to the electrochemically active surface area show very remarkable enhancement in activity of Nb-TiO2/Pt expressed through the value of the current density at the constant potential. Moreover, Nb-TiO2/Pt catalyst exhibits higher methanol tolerance during the oxygen reduction reaction than the C/Pt catalyst. The enhancement in the activity of Nb-TiO2/Pt is consequence of both: the interactions of Pt nanoparticles with the support and the energy shift of the surface d-states with respect to the Fermi level what changes the surface reactivity. (C) 2010 Elsevier B.V. All rights reserved.",
journal = "Journal of Power Sources",
title = "Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction",
volume = "195",
number = "13",
pages = "3961-3968",
doi = "10.1016/j.jpowsour.2010.01.035"
}

Elezovic, N. R., Babić, B. M., Gajic-Krstajic, Lj., Radmilović, V., Krstajic, N. V.,& Vracar, L. J.. (2010). Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction. in Journal of Power Sources, 195(13), 3961-3968.
https://doi.org/10.1016/j.jpowsour.2010.01.035

Elezovic NR, Babić BM, Gajic-Krstajic L, Radmilović V, Krstajic NV, Vracar LJ. Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction. in Journal of Power Sources. 2010;195(13):3961-3968.
doi:10.1016/j.jpowsour.2010.01.035 .

Elezovic, N. R., Babić, Biljana M., Gajic-Krstajic, Lj., Radmilović, Velimir, Krstajic, N. V., Vracar, L. J., "Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction" in Journal of Power Sources, 195, no. 13 (2010):3961-3968,
https://doi.org/10.1016/j.jpowsour.2010.01.035 . .

TY  - JOUR
AU  - Babić, Biljana M.
AU  - Gulicovski, Jelena J.
AU  - Gajic-Krstajic, Lj.
AU  - Elezovic, N.
AU  - Radmilovíć, Velimir R.
AU  - Krstajic, N. V.
AU  - Vracar, Lj. M.
PY  - 2009
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3731
AB  - The kinetics and mechanism of the hydrogen oxidation reaction were studied in 0.5 mol dm(-3) HClO(4) solution on an electrode based on titanium oxide with Magneli phase structure-supported platinum electrocatalyst applied on rotation Au disk electrode. Pt catalyst was prepared by impregnation method from 2-propanol solution of Pt(NH(3))(2)(NO(2))(2) and sub-stoichiometric titanium oxide powder. Sub-stiochiometric titanium oxide Support was characterized by X-ray diffraction and BET techniques. The synthesized catalyst was analyzed by TEM technique. Based on Tafel-Heyrovsky-Volmer mechanism the corresponding kinetic equations were derived to describe the hydrogen oxidation current-potential behavior on RDE over the entire potential region. The polarization RIDE curves were fitted with derived polarization equations according to proposed model. The fitting shows that the HOR on Pt proceeds most likely via the Tafel-Volmer (TV) pathway in the lower potential region, while the Heyrovsky-Volmer (HV) pathway is operative in the higher potential region. It is pointed out that Tafel equation that has been frequently used for the kinetics analysis in the HOR, can not reproduce the polarization curves measured with high mass-transport rates. Polarization measurements on RDE revealed that the Pt catalyst deposited on titanium suboxide support showed equal specific activity for the HOR compared to conventional carbon-supported Pt fuel cell catalyst. (C) 2008 Elsevier B.V. All rights reserved.
T2  - Journal of Power Sources
T1  - Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution
VL  - 193
IS  - 1
SP  - 99
EP  - 106
DO  - 10.1016/j.jpowsour.2008.11.142
ER  - 

@article{
author = "Babić, Biljana M. and Gulicovski, Jelena J. and Gajic-Krstajic, Lj. and Elezovic, N. and Radmilovíć, Velimir R. and Krstajic, N. V. and Vracar, Lj. M.",
year = "2009",
abstract = "The kinetics and mechanism of the hydrogen oxidation reaction were studied in 0.5 mol dm(-3) HClO(4) solution on an electrode based on titanium oxide with Magneli phase structure-supported platinum electrocatalyst applied on rotation Au disk electrode. Pt catalyst was prepared by impregnation method from 2-propanol solution of Pt(NH(3))(2)(NO(2))(2) and sub-stoichiometric titanium oxide powder. Sub-stiochiometric titanium oxide Support was characterized by X-ray diffraction and BET techniques. The synthesized catalyst was analyzed by TEM technique. Based on Tafel-Heyrovsky-Volmer mechanism the corresponding kinetic equations were derived to describe the hydrogen oxidation current-potential behavior on RDE over the entire potential region. The polarization RIDE curves were fitted with derived polarization equations according to proposed model. The fitting shows that the HOR on Pt proceeds most likely via the Tafel-Volmer (TV) pathway in the lower potential region, while the Heyrovsky-Volmer (HV) pathway is operative in the higher potential region. It is pointed out that Tafel equation that has been frequently used for the kinetics analysis in the HOR, can not reproduce the polarization curves measured with high mass-transport rates. Polarization measurements on RDE revealed that the Pt catalyst deposited on titanium suboxide support showed equal specific activity for the HOR compared to conventional carbon-supported Pt fuel cell catalyst. (C) 2008 Elsevier B.V. All rights reserved.",
journal = "Journal of Power Sources",
title = "Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution",
volume = "193",
number = "1",
pages = "99-106",
doi = "10.1016/j.jpowsour.2008.11.142"
}

Babić, B. M., Gulicovski, J. J., Gajic-Krstajic, Lj., Elezovic, N., Radmilovíć, V. R., Krstajic, N. V.,& Vracar, Lj. M.. (2009). Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution. in Journal of Power Sources, 193(1), 99-106.
https://doi.org/10.1016/j.jpowsour.2008.11.142

Babić BM, Gulicovski JJ, Gajic-Krstajic L, Elezovic N, Radmilovíć VR, Krstajic NV, Vracar LM. Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution. in Journal of Power Sources. 2009;193(1):99-106.
doi:10.1016/j.jpowsour.2008.11.142 .

Babić, Biljana M., Gulicovski, Jelena J., Gajic-Krstajic, Lj., Elezovic, N., Radmilovíć, Velimir R., Krstajic, N. V., Vracar, Lj. M., "Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution" in Journal of Power Sources, 193, no. 1 (2009):99-106,
https://doi.org/10.1016/j.jpowsour.2008.11.142 . .