SO2 on TiO2(110) and Ti2O3(101̄2) Nonpolar Surfaces:  A DFT Study

Casarin, Maurizio; Ferrigato, Francesca; Maccato, Chiara; Vittadini, Andrea

doi:10.1021/jp050314e

Cited by 31 publications

(30 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…DFT calculations predict a stable SO 3 2− species on “perfect” TiO 2 (110) (i.e., a surface without bridging oxygen vacancies). In this case, the SO 2 molecule is bound to the substrate through all three atoms: the S atom to an in‐plane oxygen atom and the two SO 2 oxygen atoms each to a fivefold‐coordinated Ti atom (Figure 1 e) 6–8. This model is consistent with the position derived from STM, as the S atom is laterally displaced from the Ti row by about 1 Å.…”

supporting

confidence: 77%

“…The adsorbate does not appear to interact with oxygen vacancies at this temperature. The position of the adsorbate is consistent with a species predicted to be stable by DFT calculations in which the two O atoms in the SO 2 molecule bridge adjacent fivefold‐coordinated Ti atoms 6–8. The S atom bonds to an in‐plane O atom.…”

supporting

confidence: 75%

“…This system has been examined experimentally with near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy2 and photoemission spectroscopy 3–6. Density functional theory (DFT) calculations have also been used to provide insight into the important factors influencing complex‐anion formation 6–8. The spectroscopic results indicate the formation of SO 3 2− (sulfite) and SO 4 2− (sulfate) like species above 120 K, the relative concentrations of which are dependent on the temperature of the substrate 3.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Visualization of Complex‐Anion Site Conversion on a Metal Oxide Surface

et al. 2007

View full text Add to dashboard Cite

Molecular adsorption on a metal oxide surface differs fundamentally from that on a metal surface because complex-anion formation is a potential outcome. These species are technologically important. For example, they are likely to be involved when sulfur dioxide is removed from a gas stream by sorption onto a dispersed oxide. Despite the importance of such processes, there is still relatively little understanding of molecular adsorption on metal oxides at the microscopic level. One of the best studied adsorption systems in which complex anions are involved is SO 2 on the model oxide substrate TiO 2 (110)1 1.[1] This system has been examined experimentally with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy [2] and photoemission spectroscopy. [3][4][5][6] Density functional theory (DFT) calculations have also been used to provide insight into the important factors influencing complex-anion formation. [6][7][8] The spectroscopic results indicate the formation of SO 3 2À (sulfite) and SO 4 2À(sulfate) like species above 120 K, the relative concentrations of which are dependent on the temperature of the substrate.[3]The DFT results point to the pivotal role of oxygen vacancies in stabilizing both sulfite and sulfate adsorbates. Herein, we use variable-temperature scanning tunneling microscopy (STM) to follow the reaction of SO 2 with TiO 2 (110) between 120 and 420 K. We image a new phenomenon, namely, conversion of the complex-anion site. This conversion appears to be driven by stabilization of the adsorbates by the oxygen vacancies at elevated temperatures and is consistent with theoretical predictions.[7]Figure 1 a shows an STM image of TiO 2 (110) at 120 K prior to exposure to SO 2 . The bright rows, which lie in the [001] substrate azimuth, arise from tunneling into fivefoldcoordinated Ti atoms.[1] Figure 1 b shows part of the same area of the surface following exposure to 0.2 L (1 langmuir = 1.32 10 À6 mbar s) SO 2 . A number of small, bright features randomly distributed over the substrate terraces appear, three appearing in the area imaged in Figure 1 b. These features are ascribed to sulfite species on the basis of the spectroscopic data [3,5] and are imaged close to the Ti rows. Bridging oxygen vacancies were recently shown to play an important part in the reaction of H 2 O with TiO 2 (110). [9,10] Defects on other oxide surfaces, such as MgO (001), [11] were

show abstract

supporting

confidence: 77%

supporting

confidence: 75%

mentioning

confidence: 99%

See 1 more Smart Citation

Visualization of Complex‐Anion Site Conversion on a Metal Oxide Surface

et al. 2007

View full text Add to dashboard Cite

show abstract

“…The most effective way to remove this hazardous gas has been proven to be its catalytic oxidation to SO 3 or other sulfur oxides before its emission. Accordingly, much attention has been recently paid to the low‐temperature oxidation of SO 2 , due to its importance in solving the increasing environmental problems . Though, considerable efforts have been devoted to oxidation of SO 2 by various noble metals .…”

Section: Introductionmentioning

confidence: 99%

Single Si atom supported on defective boron nitride nanosheet as a promising metal‐free catalyst for N₂O reduction by CO or SO₂ molecule: A computational study

Esrafili

2018

Int J of Quantum Chemistry

View full text Add to dashboard Cite

The low-temperature reduction of N 2 O plays a significant role for solving the growing environmental and health issues caused by emission of this greenhouse gas. The aim of this study is to investigate the possible reaction pathways for the reduction of N 2 O by CO or SO 2 molecule over Si-doped boron nitride nanosheet (Si-BNNS). According to our results, a B or N-vacancy defect in BN sheet could be able to greatly stabilize the single Si adatom. The relatively large diffusion barrier for the Si atom over the defective BN sheet also indicates Si-BNNS is stable enough to be utilized in catalytic reduction of N 2 O. The large charge-transfer from the surface to N 2 O leads to the spontaneous dissociation of this molecule into N 2 molecule and an activated oxygen atom (O ads ). The O ads moiety is then eliminated by CO or SO 2 molecule. The calculated activation energies and reaction energies reveal that the Si atom located on top of the B-vacancy site has a large catalytic activity toward the reduction of N 2 O by CO or SO 2 .adsorption, BN sheet, DFT, mechanism, N2O reduction 1 | I N TR ODU C TI ON Despite large efforts devoted to the development of renewable energy sources, fossil fuels now supply about 80% of the world's energy needs.However, these energy sources are closely linked with the emission of several hazardous gases, which contribute to undesirable health problems and climate changes. [1] Nitrous oxide (N 2 O) is a main greenhouse gas with important contribution to global warming, ozone depletion and acid rain formation. [2] Hence, the development of efficient technology to control N 2 O emission has attracted much interest in recent years. [3][4][5][6][7] The most commonly used approach to reduce N 2 O emission is its selective catalytic reduction with potential reducing agents. Among these, the catalytic reduction of N 2 O by CO molecule seems more effective, [8][9][10][11][12][13][14][15] since CO is cheap and readily available. Besides, this method is beneficial since toxic CO is removed from the atmosphere at the same time. However, sulfur dioxide (SO 2 ) is another important air pollutant, coming mainly from incomplete burning of fossil fuels in automobiles and industrial processes. [16] The most effective way to remove this hazardous gas has been proven to be its catalytic oxidation to SO 3 or other sulfur oxides before its emission. Accordingly, much attention has been recently paid to the low-temperature oxidation of SO 2 , due to its importance in solving the increasing environmental problems. [17][18][19][20][21][22][23] Though, considerable efforts have been devoted to oxidation of SO 2 by various noble metals. [24,25] However, these noble metal catalysts are scare, expensive and usually need high reaction temperature for efficient operation, which hinder their large-scale application. Therefore, the development of efficient metal-free catalysts for low-temperature oxidation of SO 2 remains a significant challenge.Recently, boron nitride (BN) nanomaterials have been widely studied as promi...

show abstract

“…8,96,123 In the case of titanium dioxide, there have been several infrared and theoretical studies on SO 2 heterogeneous interactions with anatase and rutile TiO 2 surfaces. 8,124,125 More recently, attention has been focused on these heterogeneous interactions and their dependence on environmental conditions. 8 In a recent study on nanoparticles, in an experimental apparatus that has been previously described in detail.…”

Section: Introductionmentioning

confidence: 99%

Heterogeneous chemistry and photochemistry of atmospherically relevant gases on oxide surfaces

Nanayakkara¹

View full text Add to dashboard Cite

Most importantly, a very special thank you for my parents for endless support and love from my birthday all the way to this very special moment. You always trusted me, had faith on me, continuously inspired me to pursue the goals in my life and stayed with me in all the happy and sad moments. Then my loving wife Ayeshani, who always stayed by my side, encouraged and supported to complete my experiments, publications, and thesis to achieve best in my career. Special thank to you for the support and understanding throughout my graduate study and encouragement during my thesis writing. v ABSTRACT Metal oxides in the atmosphere emitted from various natural and anthropogenic processes alter the chemical balance of the Earth's atmosphere due to heterogeneous and photochemical processes with atmospheric trace gases. Therefore, understanding the heterogeneous chemistry and heterogeneous photochemistry of atmospheric trace gases on these oxide surfaces has become vital to precisely predict the effect of mineral dust loading on the Earth's atmosphere. Among the various components of mineral dust, light absorbing oxides play a significantly important role during the daytime. The work reported herein has focused mainly on TiO2 and -Fe2O3. These are light adsorbing components found in atmospheric mineral dust. Apart from being a component of mineral dust, TiO2 is heavily used in a number of industrial applications ranging from uses in self-cleaning, water purification to cosmetics. These applications have led to their presence in the atmosphere as anthropogenic dust particles and in contact with the atmosphere as a stationary phase. Iron-containing particles are transferred to the atmosphere mainly from wind and volcanic activities in the form of iron-containing mineral dust and volcanic ash aerosols. -Fe2O3 is the most stable iron containing compound found in the Earths' crust which constitutes in significant amounts in mineral dust. The presence of these oxide surfaces in the atmosphere can play a major role in heterogeneous chemistry and photochemistry. In this dissertation research, transmission FTIR spectroscopy and X-ray photoelectron spectroscopy are used to probe the details of heterogeneous chemistry and photochemistry of CO2, SO2, NO2, HCOOH, and HNO3 on titanium dioxide and hematite vi surfaces. Adsorption sites, surface speciation and surface species stability have been determined from analysis of FTIR and XPS spectra. Isotope labeling experiments were also carried out in order to obtain mechanistic information about the details of surface hydroxyl group reactivity on these oxide particle surfaces. Furthermore, heterogeneous photochemical reactions of adsorbates from atmospheric trace gas adsorption on TiO2 and -Fe2O3 were investigated under the conditions pertinent to troposphere. The role of adsorbed water on the stability of adsorbed species that form as a result of heterogeneous reactions and the effect of relative humidity on photochemistry on these oxide particles surfaces has also been investigated due t...

show abstract

SO₂ on TiO₂(110) and Ti₂O₃(101̄2) Nonpolar Surfaces: A DFT Study

Cited by 31 publications

References 42 publications

Visualization of Complex‐Anion Site Conversion on a Metal Oxide Surface

Visualization of Complex‐Anion Site Conversion on a Metal Oxide Surface

Single Si atom supported on defective boron nitride nanosheet as a promising metal‐free catalyst for N₂O reduction by CO or SO₂ molecule: A computational study

Heterogeneous chemistry and photochemistry of atmospherically relevant gases on oxide surfaces

Contact Info

Product

Resources

About

SO2 on TiO2(110) and Ti2O3(101̄2) Nonpolar Surfaces: A DFT Study

Cited by 31 publications

References 42 publications

Visualization of Complex‐Anion Site Conversion on a Metal Oxide Surface

Visualization of Complex‐Anion Site Conversion on a Metal Oxide Surface

Single Si atom supported on defective boron nitride nanosheet as a promising metal‐free catalyst for N2O reduction by CO or SO2 molecule: A computational study

Heterogeneous chemistry and photochemistry of atmospherically relevant gases on oxide surfaces

Contact Info

Product

Resources

About

SO₂ on TiO₂(110) and Ti₂O₃(101̄2) Nonpolar Surfaces: A DFT Study

Single Si atom supported on defective boron nitride nanosheet as a promising metal‐free catalyst for N₂O reduction by CO or SO₂ molecule: A computational study