Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 56-63 |
| Seitenumfang | 8 |
| Fachzeitschrift | Surface science |
| Jahrgang | 679 |
| Frühes Online-Datum | 31 Aug. 2018 |
| Publikationsstatus | Veröffentlicht - Jan. 2019 |
Abstract
The behavior of ultrathin layers of nickel (0.5 ≤ θNi ≤ 1.4 monolayers (ML)) on Rh(110) has been studied in oxidation/reduction experiments with O2 and H2 at T = 770 K. The reaction has been followed with Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS) and scanning photoelectron microscopy (SPEM). The adsorption of oxygen leads to a large decrease (up to 90%) of the Ni signal in AES. Subsequent titration with hydrogen restores nearly the initial Ni signal. The peculiar behavior of Ni on Rh(110) upon O2 adsorption is attributed to a large nucleation barrier for Ni oxide formation on Rh(110). This barrier leads to the preferential formation of chemisorbed oxygen on Rh sites forcing Ni into subsurface sites. SPEM reveals that also small NiO particles with a diameter of ≈1 µm develop during O2 adsorption. For comparison, a Rh(110) surface with a thick Ni layer of an estimated thickness of about 8–9 ML has been prepared. On this thick Ni layer Ni oxide develops spontaneously during O2 adsorption in the in 10−6 mbar range at T = 770 K.
ASJC Scopus Sachgebiete
- Physik und Astronomie (insg.)
- Physik der kondensierten Materie
- Physik und Astronomie (insg.)
- Oberflächen und Grenzflächen
- Werkstoffwissenschaften (insg.)
- Oberflächen, Beschichtungen und Folien
- Werkstoffwissenschaften (insg.)
- Werkstoffchemie
Zitieren
- Standard
- Harvard
- Apa
- Vancouver
- BibTex
- RIS
in: Surface science, Jahrgang 679, 01.2019, S. 56-63.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Large nucleation barrier for Ni oxide on Rh(110) driving Ni into subsurface sites upon oxidation
AU - Homann, Mathias
AU - von Boehn, Bernhard
AU - Malhotra, Arjun
AU - Gregoratti, Luca
AU - Amati, Matteo
AU - Zeller, Patrick
AU - Imbihl, Ronald
N1 - Funding Information: The authors are indebted to the DFG (Deutsche Forschungsgemeinschaft) for financial support.
PY - 2019/1
Y1 - 2019/1
N2 - The behavior of ultrathin layers of nickel (0.5 ≤ θNi ≤ 1.4 monolayers (ML)) on Rh(110) has been studied in oxidation/reduction experiments with O2 and H2 at T = 770 K. The reaction has been followed with Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS) and scanning photoelectron microscopy (SPEM). The adsorption of oxygen leads to a large decrease (up to 90%) of the Ni signal in AES. Subsequent titration with hydrogen restores nearly the initial Ni signal. The peculiar behavior of Ni on Rh(110) upon O2 adsorption is attributed to a large nucleation barrier for Ni oxide formation on Rh(110). This barrier leads to the preferential formation of chemisorbed oxygen on Rh sites forcing Ni into subsurface sites. SPEM reveals that also small NiO particles with a diameter of ≈1 µm develop during O2 adsorption. For comparison, a Rh(110) surface with a thick Ni layer of an estimated thickness of about 8–9 ML has been prepared. On this thick Ni layer Ni oxide develops spontaneously during O2 adsorption in the in 10−6 mbar range at T = 770 K.
AB - The behavior of ultrathin layers of nickel (0.5 ≤ θNi ≤ 1.4 monolayers (ML)) on Rh(110) has been studied in oxidation/reduction experiments with O2 and H2 at T = 770 K. The reaction has been followed with Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS) and scanning photoelectron microscopy (SPEM). The adsorption of oxygen leads to a large decrease (up to 90%) of the Ni signal in AES. Subsequent titration with hydrogen restores nearly the initial Ni signal. The peculiar behavior of Ni on Rh(110) upon O2 adsorption is attributed to a large nucleation barrier for Ni oxide formation on Rh(110). This barrier leads to the preferential formation of chemisorbed oxygen on Rh sites forcing Ni into subsurface sites. SPEM reveals that also small NiO particles with a diameter of ≈1 µm develop during O2 adsorption. For comparison, a Rh(110) surface with a thick Ni layer of an estimated thickness of about 8–9 ML has been prepared. On this thick Ni layer Ni oxide develops spontaneously during O2 adsorption in the in 10−6 mbar range at T = 770 K.
KW - Alloy
KW - Nickel
KW - Oxidation
KW - Reduction
KW - Rhodium
KW - Segregation
UR - http://www.scopus.com/inward/record.url?scp=85053045732&partnerID=8YFLogxK
U2 - 10.1016/j.susc.2018.08.029
DO - 10.1016/j.susc.2018.08.029
M3 - Article
AN - SCOPUS:85053045732
VL - 679
SP - 56
EP - 63
JO - Surface science
JF - Surface science
SN - 0039-6028
ER -