Abstract
With the recent advances in sustainable ammonia production, the ammonia oxidation reaction (AOR) has gained interest. In this work, we present an evaluation of the performance of electrochemically roughened platinum electrodes (PtR) for aqueous AOR. Platinum electrodes were modified using square wave voltammetry at various frequencies in 0.5 M H2SO4. Platinum electrodes modified at frequencies in excess of 1 kHz tended to develop nano-structured surfaces with corresponding increases in the proportion of the active {311} phase of platinum resulting in improved AOR activity. Of the different surface structures formed by the roughening process, trigonal nano-pyramids (TNPs) with small average cross sections of 20 ± 5 nm showed the greatest degree of enhancement (550% increase in peak current density relative to polycrystalline platinum. With further optimization of these roughening techniques, PtR electrodes may prove useful in as anodes in ammonia sensing applications and in fuel cells.
| Original language | English |
|---|---|
| Pages (from-to) | 778-783 |
| Number of pages | 6 |
| Journal | Electrochimica Acta |
| Volume | 297 |
| DOIs | |
| Publication status | Published - 20 Feb 2019 |
Keywords
- Ammonia oxidation
- Preferential faceting
- Roughened platinum
- Square wave voltammetry
- Trigonal nano-pyramids
Cite this
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Electro-oxidation of ammonia on electrochemically roughened platinum electrodes. / Johnston, Sam; Suryanto, Bryan H.R.; MacFarlane, Douglas R.
In: Electrochimica Acta, Vol. 297, 20.02.2019, p. 778-783.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Electro-oxidation of ammonia on electrochemically roughened platinum electrodes
AU - Johnston, Sam
AU - Suryanto, Bryan H.R.
AU - MacFarlane, Douglas R.
PY - 2019/2/20
Y1 - 2019/2/20
N2 - With the recent advances in sustainable ammonia production, the ammonia oxidation reaction (AOR) has gained interest. In this work, we present an evaluation of the performance of electrochemically roughened platinum electrodes (PtR) for aqueous AOR. Platinum electrodes were modified using square wave voltammetry at various frequencies in 0.5 M H2SO4. Platinum electrodes modified at frequencies in excess of 1 kHz tended to develop nano-structured surfaces with corresponding increases in the proportion of the active {311} phase of platinum resulting in improved AOR activity. Of the different surface structures formed by the roughening process, trigonal nano-pyramids (TNPs) with small average cross sections of 20 ± 5 nm showed the greatest degree of enhancement (550% increase in peak current density relative to polycrystalline platinum. With further optimization of these roughening techniques, PtR electrodes may prove useful in as anodes in ammonia sensing applications and in fuel cells.
AB - With the recent advances in sustainable ammonia production, the ammonia oxidation reaction (AOR) has gained interest. In this work, we present an evaluation of the performance of electrochemically roughened platinum electrodes (PtR) for aqueous AOR. Platinum electrodes were modified using square wave voltammetry at various frequencies in 0.5 M H2SO4. Platinum electrodes modified at frequencies in excess of 1 kHz tended to develop nano-structured surfaces with corresponding increases in the proportion of the active {311} phase of platinum resulting in improved AOR activity. Of the different surface structures formed by the roughening process, trigonal nano-pyramids (TNPs) with small average cross sections of 20 ± 5 nm showed the greatest degree of enhancement (550% increase in peak current density relative to polycrystalline platinum. With further optimization of these roughening techniques, PtR electrodes may prove useful in as anodes in ammonia sensing applications and in fuel cells.
KW - Ammonia oxidation
KW - Preferential faceting
KW - Roughened platinum
KW - Square wave voltammetry
KW - Trigonal nano-pyramids
UR - http://www.scopus.com/inward/record.url?scp=85059323729&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2018.12.014
DO - 10.1016/j.electacta.2018.12.014
M3 - Article
VL - 297
SP - 778
EP - 783
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
ER -