TY  - JOUR
AU  - Smiljanić, Milutin Lj.
AU  - Bele, Marjan
AU  - Moriau, Léonard Jean
AU  - Vélez Santa, John Fredy
AU  - Menart, Svit
AU  - Šala, Martin
AU  - Hrnjić, Armin
AU  - Jovanovič, Primož
AU  - Ruiz-Zepeda, Francisco
AU  - Gaberšček, Miran
AU  - Hodnik, Nejc
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10146
AB  - Degradation of carbon-supported Pt nanocatalysts in fuel cells and electrolyzers hinders widespread commercialization of these green technologies. Transition between oxidized and reduced states of Pt during fast potential spikes triggers significant Pt dissolution. Therefore, designing Pt-based catalysts able to withstand such conditions is of critical importance. We report here on a strategy to suppress Pt dissolution by using an organic matrix tris(aza)pentacene (TAP) as an alternative support material for Pt. The major benefit of TAP is its potential-dependent conductivity in aqueous media, which was directly evidenced by electrochemical impedance spectroscopy. At potentials below ∼0.45 VRHE, TAP is protonated and its conductivity is improved, which enables supported Pt to run hydrogen reactions. At potentials corresponding to Pt oxidation/reduction (>∼0.45 VRHE), TAP is deprotonated and its conductivity is restricted. Tunable conductivity of TAP enhanced the durability of the Pt/TAP with respect to Pt/C when these two materials were subjected to the same degradation protocol (0.1 M HClO4 electrolyte, 3000 voltammetric scans, 1 V/s, 0.05-1.4 VRHE). The exceptional stability of Pt/TAP composite on a nanoscale level was confirmed by identical location TEM imaging before and after the used degradation protocol. Suppression of transient Pt dissolution from Pt/TAP with respect to the Pt/C benchmark was directly measured in a setup consisting of an electrochemical flow cell connected to inductively coupled plasma-mass spectrometry.
T2  - ACS Omega
T1  - Suppressing Platinum Electrocatalyst Degradation via a HighSurface-Area Organic Matrix Support
VL  - 7
IS  - 4
SP  - 3540
EP  - 3548
DO  - 10.1021/acsomega.1c06028
ER  - 

@article{
author = "Smiljanić, Milutin Lj. and Bele, Marjan and Moriau, Léonard Jean and Vélez Santa, John Fredy and Menart, Svit and Šala, Martin and Hrnjić, Armin and Jovanovič, Primož and Ruiz-Zepeda, Francisco and Gaberšček, Miran and Hodnik, Nejc",
year = "2021",
abstract = "Degradation of carbon-supported Pt nanocatalysts in fuel cells and electrolyzers hinders widespread commercialization of these green technologies. Transition between oxidized and reduced states of Pt during fast potential spikes triggers significant Pt dissolution. Therefore, designing Pt-based catalysts able to withstand such conditions is of critical importance. We report here on a strategy to suppress Pt dissolution by using an organic matrix tris(aza)pentacene (TAP) as an alternative support material for Pt. The major benefit of TAP is its potential-dependent conductivity in aqueous media, which was directly evidenced by electrochemical impedance spectroscopy. At potentials below ∼0.45 VRHE, TAP is protonated and its conductivity is improved, which enables supported Pt to run hydrogen reactions. At potentials corresponding to Pt oxidation/reduction (>∼0.45 VRHE), TAP is deprotonated and its conductivity is restricted. Tunable conductivity of TAP enhanced the durability of the Pt/TAP with respect to Pt/C when these two materials were subjected to the same degradation protocol (0.1 M HClO4 electrolyte, 3000 voltammetric scans, 1 V/s, 0.05-1.4 VRHE). The exceptional stability of Pt/TAP composite on a nanoscale level was confirmed by identical location TEM imaging before and after the used degradation protocol. Suppression of transient Pt dissolution from Pt/TAP with respect to the Pt/C benchmark was directly measured in a setup consisting of an electrochemical flow cell connected to inductively coupled plasma-mass spectrometry.",
journal = "ACS Omega",
title = "Suppressing Platinum Electrocatalyst Degradation via a HighSurface-Area Organic Matrix Support",
volume = "7",
number = "4",
pages = "3540-3548",
doi = "10.1021/acsomega.1c06028"
}

Smiljanić, M. Lj., Bele, M., Moriau, L. J., Vélez Santa, J. F., Menart, S., Šala, M., Hrnjić, A., Jovanovič, P., Ruiz-Zepeda, F., Gaberšček, M.,& Hodnik, N.. (2021). Suppressing Platinum Electrocatalyst Degradation via a HighSurface-Area Organic Matrix Support. in ACS Omega, 7(4), 3540-3548.
https://doi.org/10.1021/acsomega.1c06028

Smiljanić ML, Bele M, Moriau LJ, Vélez Santa JF, Menart S, Šala M, Hrnjić A, Jovanovič P, Ruiz-Zepeda F, Gaberšček M, Hodnik N. Suppressing Platinum Electrocatalyst Degradation via a HighSurface-Area Organic Matrix Support. in ACS Omega. 2021;7(4):3540-3548.
doi:10.1021/acsomega.1c06028 .

Smiljanić, Milutin Lj., Bele, Marjan, Moriau, Léonard Jean, Vélez Santa, John Fredy, Menart, Svit, Šala, Martin, Hrnjić, Armin, Jovanovič, Primož, Ruiz-Zepeda, Francisco, Gaberšček, Miran, Hodnik, Nejc, "Suppressing Platinum Electrocatalyst Degradation via a HighSurface-Area Organic Matrix Support" in ACS Omega, 7, no. 4 (2021):3540-3548,
https://doi.org/10.1021/acsomega.1c06028 . .

TY  - JOUR
AU  - Smiljanić, Milutin Lj.
AU  - Bele, Marjan
AU  - Moriau, Leonard
AU  - Ruiz-Zepeda, Francisco
AU  - Šala, Martin
AU  - Hodnik, Nejc
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10103
AB  - Palladium has attracted significant attention as a catalyst or co-catalyst for many electrochemical reactions in energy conversion devices. We have studied electrochemical stability of a commercial Pd/C sample in an acidic electrolyte by exposing it to an accelerated stress test (AST) to mimic potential spikes in fuel cells and electrolyzers during start/stop events. AST consisted of extensive rapid potential cycling (5000 cycles, 1 V/s) in two potential regions, namely AST1 was performed between 0.4 and 1.4 VRHE, while AST2 was performed between 0.05 and 1.4 VRHE. Degradation of Pd/C was monitored by the changes in Pd electrochemical surface area, while the hydrogen evolution reaction (HER) was used as a test reaction to observe the corresponding impact of the degradation on the activity of Pd/C. Significant Pd/C degradation and HER activity loss were observed in both potential regions. Coupling of the electrochemical flow cell with an inductively coupled plasma mass spectrometry device showed substantial Pd dissolution during both ASTs. Identical location scanning electron microscopy revealed that Pd dissolution is followed by redeposition during both ASTs, resulting in particle size growth. Particle size growth was seen as especially dramatic in the case of AST2, when particularly large Pd nanostructures were obtained on top of the catalyst layer. According to the results presented in this work, (in)stability of Pd/C and other Pd-based nanocatalysts should be studied systematically as it may present a key factor limiting their application in energy conversion devices.
T2  - The Journal of Physical Chemistry C
T1  - Electrochemical Stability and Degradation of Commercial Pd/C Catalyst in Acidic Media
VL  - 125
IS  - 50
SP  - 27534
EP  - 27542
DO  - 10.1021/acs.jpcc.1c08496
ER  - 

@article{
author = "Smiljanić, Milutin Lj. and Bele, Marjan and Moriau, Leonard and Ruiz-Zepeda, Francisco and Šala, Martin and Hodnik, Nejc",
year = "2021",
abstract = "Palladium has attracted significant attention as a catalyst or co-catalyst for many electrochemical reactions in energy conversion devices. We have studied electrochemical stability of a commercial Pd/C sample in an acidic electrolyte by exposing it to an accelerated stress test (AST) to mimic potential spikes in fuel cells and electrolyzers during start/stop events. AST consisted of extensive rapid potential cycling (5000 cycles, 1 V/s) in two potential regions, namely AST1 was performed between 0.4 and 1.4 VRHE, while AST2 was performed between 0.05 and 1.4 VRHE. Degradation of Pd/C was monitored by the changes in Pd electrochemical surface area, while the hydrogen evolution reaction (HER) was used as a test reaction to observe the corresponding impact of the degradation on the activity of Pd/C. Significant Pd/C degradation and HER activity loss were observed in both potential regions. Coupling of the electrochemical flow cell with an inductively coupled plasma mass spectrometry device showed substantial Pd dissolution during both ASTs. Identical location scanning electron microscopy revealed that Pd dissolution is followed by redeposition during both ASTs, resulting in particle size growth. Particle size growth was seen as especially dramatic in the case of AST2, when particularly large Pd nanostructures were obtained on top of the catalyst layer. According to the results presented in this work, (in)stability of Pd/C and other Pd-based nanocatalysts should be studied systematically as it may present a key factor limiting their application in energy conversion devices.",
journal = "The Journal of Physical Chemistry C",
title = "Electrochemical Stability and Degradation of Commercial Pd/C Catalyst in Acidic Media",
volume = "125",
number = "50",
pages = "27534-27542",
doi = "10.1021/acs.jpcc.1c08496"
}

Smiljanić, M. Lj., Bele, M., Moriau, L., Ruiz-Zepeda, F., Šala, M.,& Hodnik, N.. (2021). Electrochemical Stability and Degradation of Commercial Pd/C Catalyst in Acidic Media. in The Journal of Physical Chemistry C, 125(50), 27534-27542.
https://doi.org/10.1021/acs.jpcc.1c08496

Smiljanić ML, Bele M, Moriau L, Ruiz-Zepeda F, Šala M, Hodnik N. Electrochemical Stability and Degradation of Commercial Pd/C Catalyst in Acidic Media. in The Journal of Physical Chemistry C. 2021;125(50):27534-27542.
doi:10.1021/acs.jpcc.1c08496 .

Smiljanić, Milutin Lj., Bele, Marjan, Moriau, Leonard, Ruiz-Zepeda, Francisco, Šala, Martin, Hodnik, Nejc, "Electrochemical Stability and Degradation of Commercial Pd/C Catalyst in Acidic Media" in The Journal of Physical Chemistry C, 125, no. 50 (2021):27534-27542,
https://doi.org/10.1021/acs.jpcc.1c08496 . .