CO adsorption on metal‐oxide surfaces doped with transition‐metal adatoms

Blomqvist, Janne; Lehman, L.M.; Salo, Petri

doi:10.1002/pssb.201147334

Cited by 12 publications

(6 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Whereas the refilling of the oxygen vacancies in reducible oxides such as CeO x stimulates the oxygen dissociation on the oxide-island adjacent surface sites, this is not the case for SiO 2 . In turn, the spillover of CO from the SiO 2 islands (a weakly bound mobile CO layer can be formed on the SiO 2 surface [35]) supports the interpretation that the regions around the SiO 2 islands must be rather inactive for the CO oxidation.…”

Section: Resultsmentioning

confidence: 82%

Silicon Oxide Surface Segregation in CO Oxidation on Pd: An in situ PEEM, MS and XPS Study

et al. 2013

View full text Add to dashboard Cite

The effect of silicon oxide surface segregation on the locally-resolved kinetics of the CO oxidation reaction on individual grains of a polycrystalline Pd foil was studied in situ by PEEM, MS and XPS. The silicon oxide formation induced by Si-impurity segregation at oxidizing conditions, was monitored by XPS and its impact on the global and local (spatially resolved) kinetics of the CO oxidation was determined by MS and PEEM. The results reveal a drastic inhibiting effect of silicon oxide on the Pd reactivity towards CO oxidation, manifested both in the collapse of the global CO2 formation rate and in the modified local reactive properties of individual Pd micrograins. The presence of adsorbed oxygen on the Pd surface effectively enhances the silicon segregation to the Pd surface.Graphical Abstract

show abstract

Section: Resultsmentioning

confidence: 82%

Silicon Oxide Surface Segregation in CO Oxidation on Pd: An in situ PEEM, MS and XPS Study

et al. 2013

View full text Add to dashboard Cite

show abstract

“…In a work focusing on the adsorption of CO onto a-Al 2 O 3 (0001) and onto Pd and Ag deposited on a-Al 2 O 3 (0001) it was found that adsorption is preferred on the metal and not on the surface site adjacent to the metal. 58 This was not due to the larger adsorption energy of CO on Ag deposited on a-Al 2 O 3 (0001) (E a CO on Ag/a-Al 2 O 3 (0001) = 0.6 eV and E a CO on a-Al 2 O 3 (0001) = 0.53 eV) but mainly because of the structural effects. Similar observations related to energy differences were found for Au/ Al 2 O 3 although with subtle differences.…”

Section: The Hydroxylated (0001) Surface Of A-al 2 Omentioning

confidence: 96%

A DFT study on carbon monoxide adsorption onto hydroxylated α-Al₂O₃(0001) surfaces

Rohmann

Metson

Idriss

2014

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

The adsorption of CO onto the hydroxylated α-Al2O3(0001) surface was studied using density functional theory (DFT). Dissociated adsorption of water was found to be stable, with an adsorption energy (Ea) of 1.62 eV at θ(water) = 0.75. The most stable hydroxylation form on the clean surface was found to be in the 1-2 dissociation configuration, where the OH group binds to a surface Al ion and the H ion binds to one of the three equivalent surface O ions. The adsorption energy of CO was found to be dependent on the degree of pre-hydroxylation of the surface as well as on the CO coverage. The highest adsorption energy of CO was found when θ(CO) = 0.25 on a pre-hydroxylated surface with θ(water) = 0.25; Ea = 0.57 eV. The adsorption energy of CO decreased upon increasing the degree of pre-hydroxylation. The vibrational frequency of ν(CO) was also computed and in all cases it was blue shifted with respect to gas-phase CO. The shift, Δν, decreased with increasing CO coverage but increased with increasing surface hydroxylation. A comparison with available experimental work is discussed.

show abstract

“…Very recently, Blomqvist et al 86 used generalized gradient approximation (GGA) in combination with plane wave basis set to study CO and transition metal (Ag and Pd) ad-atom co-adsorption on the α-Al 2 O 3 (0001) surface. The estimated binding energy of CO was −11.53 kcal/mol (independently of the surface site) in good agreement with the value of −12.97 kcal/mol determined in this work.…”

Section: Co Adsorption On Undoped and Fe3+ And Cr3+ Doped α-Al2o3 (00mentioning

confidence: 99%

Electronic Properties and Reactivity of Simulated Fe³⁺and Cr³⁺Substituted α-Al₂O₃(0001) Surface

2012

View full text Add to dashboard Cite

Metal oxide based minerals naturally contain transition metal impurities isomorphically substituted into the structure that can alter the structural and electronic properties as well as the reactivity of these metal oxides. Natural α-Al2O3 (corundum) can contain up to 9.17% (w/w) Fe2O3 and 1.81% (w/w) of Cr2O3. Here we report on changes in the structural and electronic properties of undoped and doped α-Al2O3 (0001) surfaces using periodic density functional theory (DFT) methods with spin unrestricted B3LYP functional and a local atomic basis set. Both structural and electronic properties are altered upon doping. Implications for doping effects on photochemical processes are discussed. As metal oxides are major components of the environment, including atmospheric mineral aerosol, DFT was also used to study the effect of transition metal impurities on gas/surface interactions of a model acidic atmospheric gas molecule, carbon monoxide (CO). The theoretical results indicated that the presence of Fe3+ and Cr3+ impurities substituted on the outer layer of natural corundum surfaces reduces the propensity toward CO adsorption relative to the undoped surface. However, CO-surface interactions resemble that of bulk α-Al2O3 when the impurity is substituted below the first surface layer. The presence and location of the mineral dopant was found to significantly alter the structural and electronic properties and gas/surface interactions studied here.

show abstract

CO adsorption on metal‐oxide surfaces doped with transition‐metal adatoms

Cited by 12 publications

References 55 publications

Silicon Oxide Surface Segregation in CO Oxidation on Pd: An in situ PEEM, MS and XPS Study

Silicon Oxide Surface Segregation in CO Oxidation on Pd: An in situ PEEM, MS and XPS Study

A DFT study on carbon monoxide adsorption onto hydroxylated α-Al₂O₃(0001) surfaces

Electronic Properties and Reactivity of Simulated Fe³⁺and Cr³⁺Substituted α-Al₂O₃(0001) Surface

Contact Info

Product

Resources

About

CO adsorption on metal‐oxide surfaces doped with transition‐metal adatoms

Cited by 12 publications

References 55 publications

Silicon Oxide Surface Segregation in CO Oxidation on Pd: An in situ PEEM, MS and XPS Study

Silicon Oxide Surface Segregation in CO Oxidation on Pd: An in situ PEEM, MS and XPS Study

A DFT study on carbon monoxide adsorption onto hydroxylated α-Al2O3(0001) surfaces

Electronic Properties and Reactivity of Simulated Fe3+and Cr3+Substituted α-Al2O3(0001) Surface

Contact Info

Product

Resources

About

A DFT study on carbon monoxide adsorption onto hydroxylated α-Al₂O₃(0001) surfaces

Electronic Properties and Reactivity of Simulated Fe³⁺and Cr³⁺Substituted α-Al₂O₃(0001) Surface