Slovenian Research Agency [P1-0034, P2-0393, N2-0106]

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Slovenian Research Agency [P1-0034, P2-0393, N2-0106]

Authors

Publications

Electrochemical Stability and Degradation of Commercial Pd/C Catalyst in Acidic Media

Smiljanić, Milutin Lj.; Bele, Marjan; Moriau, Leonard; Ruiz-Zepeda, Francisco; Šala, Martin; Hodnik, Nejc

(2021)

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 . .
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Electrochemical stability and degradation of commercial Rh/C catalyst in acidic media

Smiljanić, Milutin Lj.; Bele, Marjan; Ruiz-Zepeda, Francisco; Šala, Martin; Kroflič, Ana; Hodnik, Nejc

(2021)

TY  - JOUR
AU  - Smiljanić, Milutin Lj.
AU  - Bele, Marjan
AU  - Ruiz-Zepeda, Francisco
AU  - Šala, Martin
AU  - Kroflič, Ana
AU  - Hodnik, Nejc
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9979
AB  - Electrochemical stability of a commercial Rh/C catalyst has been studied in an acidic electrolyte by accelerated degradation protocols (ADP) which involved 5000 rapid voltammetric scans (1 V/s) in two potential regions: ADP1 was performed between 0.4 VRHE and 1.4 VRHE, while ADP2 was performed between 0.05 VRHE and 1.4 VRHE. Degradation of Rh/C was monitored by the changes in Rh electrochemical surface area (ECSA) and electrocatalytic activity for hydrogen evolution (HER) and oxygen reduction (ORR). Rh/C catalyst was particularly stable during ADP1 showing only a minor loss of ECSA, while its electrocatalytic activity for HER and ORR was practically unaffected, which was further corroborated with identical location SEM (IL-SEM) imaging. In the case of ADP2, severe degradation of Rh/C occurred followed by substantial decay in its electrocatalytic activity. Coupling of the electrochemical flow cell (EFC) with ICP-MS revealed much higher Rh dissolution in ADP2 than in ADP1. IL-SEM in combination with ex-situ TEM imaging showed that degradation of the Rh/C sample is not homogeneous during ADP2, as dissolution prevails on certain locations, while dissolution followed by re-deposition occurs on others. According to the results obtained in this work, Rh/C catalysts are exceptionally sensitive to the sudden potential jumps between particularly low and high values.
T2  - Electrochimica Acta
T1  - Electrochemical stability and degradation of commercial Rh/C catalyst in acidic media
VL  - 400
SP  - 139435
DO  - 10.1016/j.electacta.2021.139435
ER  - 
@article{
author = "Smiljanić, Milutin Lj. and Bele, Marjan and Ruiz-Zepeda, Francisco and Šala, Martin and Kroflič, Ana and Hodnik, Nejc",
year = "2021",
abstract = "Electrochemical stability of a commercial Rh/C catalyst has been studied in an acidic electrolyte by accelerated degradation protocols (ADP) which involved 5000 rapid voltammetric scans (1 V/s) in two potential regions: ADP1 was performed between 0.4 VRHE and 1.4 VRHE, while ADP2 was performed between 0.05 VRHE and 1.4 VRHE. Degradation of Rh/C was monitored by the changes in Rh electrochemical surface area (ECSA) and electrocatalytic activity for hydrogen evolution (HER) and oxygen reduction (ORR). Rh/C catalyst was particularly stable during ADP1 showing only a minor loss of ECSA, while its electrocatalytic activity for HER and ORR was practically unaffected, which was further corroborated with identical location SEM (IL-SEM) imaging. In the case of ADP2, severe degradation of Rh/C occurred followed by substantial decay in its electrocatalytic activity. Coupling of the electrochemical flow cell (EFC) with ICP-MS revealed much higher Rh dissolution in ADP2 than in ADP1. IL-SEM in combination with ex-situ TEM imaging showed that degradation of the Rh/C sample is not homogeneous during ADP2, as dissolution prevails on certain locations, while dissolution followed by re-deposition occurs on others. According to the results obtained in this work, Rh/C catalysts are exceptionally sensitive to the sudden potential jumps between particularly low and high values.",
journal = "Electrochimica Acta",
title = "Electrochemical stability and degradation of commercial Rh/C catalyst in acidic media",
volume = "400",
pages = "139435",
doi = "10.1016/j.electacta.2021.139435"
}
Smiljanić, M. Lj., Bele, M., Ruiz-Zepeda, F., Šala, M., Kroflič, A.,& Hodnik, N.. (2021). Electrochemical stability and degradation of commercial Rh/C catalyst in acidic media. in Electrochimica Acta, 400, 139435.
https://doi.org/10.1016/j.electacta.2021.139435
Smiljanić ML, Bele M, Ruiz-Zepeda F, Šala M, Kroflič A, Hodnik N. Electrochemical stability and degradation of commercial Rh/C catalyst in acidic media. in Electrochimica Acta. 2021;400:139435.
doi:10.1016/j.electacta.2021.139435 .
Smiljanić, Milutin Lj., Bele, Marjan, Ruiz-Zepeda, Francisco, Šala, Martin, Kroflič, Ana, Hodnik, Nejc, "Electrochemical stability and degradation of commercial Rh/C catalyst in acidic media" in Electrochimica Acta, 400 (2021):139435,
https://doi.org/10.1016/j.electacta.2021.139435 . .
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High-surface-area organic matrix tris(aza)pentacene supported platinum nanostructures as selective electrocatalyst for hydrogen oxidation/evolution reaction and suppressive for oxygen reduction reaction

Vélez Santa, John Fredy; Menart, Svit; Bele, Marjan; Ruiz-Zepeda, Francisco; Jovanovič, Primož; Jovanovski, Vasko; Šala, Martin; Smiljanić, Milutin Lj.; Hodnik, Nejc

(2021)

TY  - JOUR
AU  - Vélez Santa, John Fredy
AU  - Menart, Svit
AU  - Bele, Marjan
AU  - Ruiz-Zepeda, Francisco
AU  - Jovanovič, Primož
AU  - Jovanovski, Vasko
AU  - Šala, Martin
AU  - Smiljanić, Milutin Lj.
AU  - Hodnik, Nejc
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9844
AB  - Developing a Pt-based electrocatalytic material able to selectively catalyze hydrogen oxidation (HOR) while supressing oxygen reduction (ORR) is beneficial for durability of the fuel cells. Namely, degradation of carbon supported Pt particles is dramatically influenced by the unwanted ORR enrolling at the anode due to the air penetration during start-up/shut-down events. We present an organic matrix tris(aza)pentacene (TAP), which belongs to π-functional materials with ladder-like conjugated nitrogen-containing units, as the support for Pt to form a “smart” fuel cell anode able to selectively catalyze HOR and to suppress ORR. “Switching-on/off” of the composite material activity is provided by reversible reduction/oxidation of the TAP in the low potential region which provokes TAP - HxTAP transition. Conductivity of the reduced HxTAP enables supported Pt particles to effectively run HOR. In contrast, restricted conductivity of oxidized TAP analogue leads to the substantial drop in the ORR activity with respect to benchmark Pt/C catalyst.
T2  - International Journal of Hydrogen Energy
T1  - High-surface-area organic matrix tris(aza)pentacene supported platinum nanostructures as selective electrocatalyst for hydrogen oxidation/evolution reaction and suppressive for oxygen reduction reaction
VL  - 46
IS  - 49
SP  - 25039
EP  - 25049
DO  - 10.1016/j.ijhydene.2021.05.041
ER  - 
@article{
author = "Vélez Santa, John Fredy and Menart, Svit and Bele, Marjan and Ruiz-Zepeda, Francisco and Jovanovič, Primož and Jovanovski, Vasko and Šala, Martin and Smiljanić, Milutin Lj. and Hodnik, Nejc",
year = "2021",
abstract = "Developing a Pt-based electrocatalytic material able to selectively catalyze hydrogen oxidation (HOR) while supressing oxygen reduction (ORR) is beneficial for durability of the fuel cells. Namely, degradation of carbon supported Pt particles is dramatically influenced by the unwanted ORR enrolling at the anode due to the air penetration during start-up/shut-down events. We present an organic matrix tris(aza)pentacene (TAP), which belongs to π-functional materials with ladder-like conjugated nitrogen-containing units, as the support for Pt to form a “smart” fuel cell anode able to selectively catalyze HOR and to suppress ORR. “Switching-on/off” of the composite material activity is provided by reversible reduction/oxidation of the TAP in the low potential region which provokes TAP - HxTAP transition. Conductivity of the reduced HxTAP enables supported Pt particles to effectively run HOR. In contrast, restricted conductivity of oxidized TAP analogue leads to the substantial drop in the ORR activity with respect to benchmark Pt/C catalyst.",
journal = "International Journal of Hydrogen Energy",
title = "High-surface-area organic matrix tris(aza)pentacene supported platinum nanostructures as selective electrocatalyst for hydrogen oxidation/evolution reaction and suppressive for oxygen reduction reaction",
volume = "46",
number = "49",
pages = "25039-25049",
doi = "10.1016/j.ijhydene.2021.05.041"
}
Vélez Santa, J. F., Menart, S., Bele, M., Ruiz-Zepeda, F., Jovanovič, P., Jovanovski, V., Šala, M., Smiljanić, M. Lj.,& Hodnik, N.. (2021). High-surface-area organic matrix tris(aza)pentacene supported platinum nanostructures as selective electrocatalyst for hydrogen oxidation/evolution reaction and suppressive for oxygen reduction reaction. in International Journal of Hydrogen Energy, 46(49), 25039-25049.
https://doi.org/10.1016/j.ijhydene.2021.05.041
Vélez Santa JF, Menart S, Bele M, Ruiz-Zepeda F, Jovanovič P, Jovanovski V, Šala M, Smiljanić ML, Hodnik N. High-surface-area organic matrix tris(aza)pentacene supported platinum nanostructures as selective electrocatalyst for hydrogen oxidation/evolution reaction and suppressive for oxygen reduction reaction. in International Journal of Hydrogen Energy. 2021;46(49):25039-25049.
doi:10.1016/j.ijhydene.2021.05.041 .
Vélez Santa, John Fredy, Menart, Svit, Bele, Marjan, Ruiz-Zepeda, Francisco, Jovanovič, Primož, Jovanovski, Vasko, Šala, Martin, Smiljanić, Milutin Lj., Hodnik, Nejc, "High-surface-area organic matrix tris(aza)pentacene supported platinum nanostructures as selective electrocatalyst for hydrogen oxidation/evolution reaction and suppressive for oxygen reduction reaction" in International Journal of Hydrogen Energy, 46, no. 49 (2021):25039-25049,
https://doi.org/10.1016/j.ijhydene.2021.05.041 . .
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