Adsorption and Reaction of NH3on Rutile TiO2(110): An STM Study

Hanna Bühlmeyer; Kræn C. Adamsen; Tao Xu; Lutz Lammich; Jörg Libuda; Jeppe V. Lauritsen; Stefan Wendt

doi:10.1021/acs.jpcc.2c01414

Adsorption and Reaction of NH₃on Rutile TiO₂(110): An STM Study

Hanna Bühlmeyer, Kræn C. Adamsen, Tao Xu, Lutz Lammich, Jörg Libuda, Jeppe V. Lauritsen^*, Stefan Wendt

^*Corresponding author for this work

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

Abstract

By means of high-resolution scanning tunneling microscopy (STM), we studied the adsorption and reaction of submonolayer NH3 on rutile TiO2(110) surfaces in different oxidation states. On a clean, reduced TiO2(110) surface with O vacancies, NH3 adsorbs at 120 K exclusively as single molecular species on surface Ti sites. On a TiO2(110) surface with H adatoms, we observed small amounts of NH3 monomers in close proximity to each other and NH3 dimers, in addition to the majority of isolated NH3 monomers. On such a surface, we found that NH3 and H adatoms can diffuse together along the [001] direction and NH3 can diffuse along the [11¯ 0] direction via "hydroxyl bridges". On an oxidized TiO2(110) surface with O adatoms (Oot) and O2 molecules, we found dimeric NH3 species and isolated OHt groups. Interestingly, there were also grouped adsorbates of NH2OH stoichiometry (singles and pairs). Following annealing at 330 K, the coverage of paired NH2OH species was much increased. We find a strong affinity of NH3 species to interact with Oot adatoms and Oot adatom pairs and propose dissociation of NH3 species at Oot adatoms. Finally, we discuss the faith of the observed adsorbates at elevated temperature.

Original language	English
Journal	Journal of Physical Chemistry C
Volume	126
Issue	15
Pages (from-to)	6590-6600
Number of pages	11
ISSN	1932-7447
DOIs	https://doi.org/10.1021/acs.jpcc.2c01414
Publication status	Published - Apr 2022

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title = "Adsorption and Reaction of NH3on Rutile TiO2(110): An STM Study",

abstract = "By means of high-resolution scanning tunneling microscopy (STM), we studied the adsorption and reaction of submonolayer NH3 on rutile TiO2(110) surfaces in different oxidation states. On a clean, reduced TiO2(110) surface with O vacancies, NH3 adsorbs at 120 K exclusively as single molecular species on surface Ti sites. On a TiO2(110) surface with H adatoms, we observed small amounts of NH3 monomers in close proximity to each other and NH3 dimers, in addition to the majority of isolated NH3 monomers. On such a surface, we found that NH3 and H adatoms can diffuse together along the [001] direction and NH3 can diffuse along the [11¯ 0] direction via {"}hydroxyl bridges{"}. On an oxidized TiO2(110) surface with O adatoms (Oot) and O2 molecules, we found dimeric NH3 species and isolated OHt groups. Interestingly, there were also grouped adsorbates of NH2OH stoichiometry (singles and pairs). Following annealing at 330 K, the coverage of paired NH2OH species was much increased. We find a strong affinity of NH3 species to interact with Oot adatoms and Oot adatom pairs and propose dissociation of NH3 species at Oot adatoms. Finally, we discuss the faith of the observed adsorbates at elevated temperature.",

author = "Hanna B{\"u}hlmeyer and Adamsen, {Kr{\ae}n C.} and Tao Xu and Lutz Lammich and J{\"o}rg Libuda and Lauritsen, {Jeppe V.} and Stefan Wendt",

note = "Publisher Copyright: {\textcopyright} 2022 American Chemical Society.",

year = "2022",

month = apr,

doi = "10.1021/acs.jpcc.2c01414",

language = "English",

volume = "126",

pages = "6590--6600",

journal = "Journal of Physical Chemistry C",

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publisher = "American Chemical Society",

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TY - JOUR

T1 - Adsorption and Reaction of NH3on Rutile TiO2(110)

T2 - An STM Study

AU - Bühlmeyer, Hanna

AU - Adamsen, Kræn C.

AU - Xu, Tao

AU - Lammich, Lutz

AU - Libuda, Jörg

AU - Lauritsen, Jeppe V.

AU - Wendt, Stefan

PY - 2022/4

Y1 - 2022/4

N2 - By means of high-resolution scanning tunneling microscopy (STM), we studied the adsorption and reaction of submonolayer NH3 on rutile TiO2(110) surfaces in different oxidation states. On a clean, reduced TiO2(110) surface with O vacancies, NH3 adsorbs at 120 K exclusively as single molecular species on surface Ti sites. On a TiO2(110) surface with H adatoms, we observed small amounts of NH3 monomers in close proximity to each other and NH3 dimers, in addition to the majority of isolated NH3 monomers. On such a surface, we found that NH3 and H adatoms can diffuse together along the [001] direction and NH3 can diffuse along the [11¯ 0] direction via "hydroxyl bridges". On an oxidized TiO2(110) surface with O adatoms (Oot) and O2 molecules, we found dimeric NH3 species and isolated OHt groups. Interestingly, there were also grouped adsorbates of NH2OH stoichiometry (singles and pairs). Following annealing at 330 K, the coverage of paired NH2OH species was much increased. We find a strong affinity of NH3 species to interact with Oot adatoms and Oot adatom pairs and propose dissociation of NH3 species at Oot adatoms. Finally, we discuss the faith of the observed adsorbates at elevated temperature.

AB - By means of high-resolution scanning tunneling microscopy (STM), we studied the adsorption and reaction of submonolayer NH3 on rutile TiO2(110) surfaces in different oxidation states. On a clean, reduced TiO2(110) surface with O vacancies, NH3 adsorbs at 120 K exclusively as single molecular species on surface Ti sites. On a TiO2(110) surface with H adatoms, we observed small amounts of NH3 monomers in close proximity to each other and NH3 dimers, in addition to the majority of isolated NH3 monomers. On such a surface, we found that NH3 and H adatoms can diffuse together along the [001] direction and NH3 can diffuse along the [11¯ 0] direction via "hydroxyl bridges". On an oxidized TiO2(110) surface with O adatoms (Oot) and O2 molecules, we found dimeric NH3 species and isolated OHt groups. Interestingly, there were also grouped adsorbates of NH2OH stoichiometry (singles and pairs). Following annealing at 330 K, the coverage of paired NH2OH species was much increased. We find a strong affinity of NH3 species to interact with Oot adatoms and Oot adatom pairs and propose dissociation of NH3 species at Oot adatoms. Finally, we discuss the faith of the observed adsorbates at elevated temperature.

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U2 - 10.1021/acs.jpcc.2c01414

DO - 10.1021/acs.jpcc.2c01414

M3 - Journal article

AN - SCOPUS:85128521829

SN - 1932-7447

VL - 126

SP - 6590

EP - 6600

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

IS - 15

ER -

Adsorption and Reaction of NH₃on Rutile TiO₂(110): An STM Study

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