scholarly journals Surface Molecule Manipulated Pt/TiO2 Catalysts for Selective Hydrogenation of Cinnamaldehyde

2021 ◽  
Author(s):  
Ran Tao ◽  
Bing-Qian Shan ◽  
Hao-Di Sun ◽  
Meng Ding ◽  
Qing-Song Xue ◽  
...  
Keyword(s):  
Selective Hydrogenation ◽  
Heterogeneous Catalysts ◽  
Selective Adsorption ◽  
Surface States ◽  
Solid Material ◽  
Sodium Formate ◽  
Band Theory ◽  
Saturated Aldehyde ◽  
Fundamental Limitation

<p>Surface states—the electronic states emerging as a solid material terminates at a surface—are usually vulnerable to contaminations and defects. This fundamental limitation has prohibited systematic studies of the potential role of surface states in surface reactions and catalysis, especially in more realistic environments. Herein, we use selective hydrogenation of <a>cinnamaldehyde</a> (CAL) on <a>platinum-covered titanium oxide</a> (Pt@P25) as a prototype reaction, and show that the competitive exchange of extra-introduced species (sodium hydroxide and sodium formate) with spontaneously formed weak bound carbonate and bicarbonate anions at Pt NPs can reconstruct the surface states, which directs the preferred adsorption of the conjugated C=O and C=C double bonds of CAL, and consequently, results in highly efficient synthesis of unsaturated alcohol cinnamyl alcohol (COL) and saturated aldehyde hydrocinnamaldehyde (HCAL) with high selectivity of 98.9% and 99.5%, respectively. Our concept of restructured surface states to tune the chemoselectivity of α, β-unsaturated aldehydes triggered by the selective adsorption of alien molecules may lead to new design principles of heterogeneous catalysts, beyond the conventional d-band theory.</p>

scholarly journals Surface Molecule Manipulated Pt/TiO2 Catalysts for Selective Hydrogenation of Cinnamaldehyde

2021 ◽  
Author(s):  
Bing-Qian Shan ◽  
Ran Tao ◽  
Kun Zhang
Keyword(s):  
Selective Hydrogenation ◽  
Heterogeneous Catalysts ◽  
Selective Adsorption ◽  
Surface States ◽  
Solid Material ◽  
Sodium Formate ◽  
Band Theory ◽  
Saturated Aldehyde ◽  
Fundamental Limitation

<p>Surface states—the electronic states emerging as a solid material terminates at a surface—are usually vulnerable to contaminations and defects. This fundamental limitation has prohibited systematic studies of the potential role of surface states in surface reactions and catalysis, especially in more realistic environments. Herein, we use selective hydrogenation of <a>cinnamaldehyde</a> (CAL) on <a>platinum-covered titanium oxide</a> (Pt@P25) as a prototype reaction, and show that the competitive exchange of extra-introduced species (sodium hydroxide and sodium formate) with spontaneously formed weak bound carbonate and bicarbonate anions at Pt NPs can reconstruct the surface states, which directs the preferred adsorption of the conjugated C=O and C=C double bonds of CAL, and consequently, results in highly efficient synthesis of unsaturated alcohol cinnamyl alcohol (COL) and saturated aldehyde hydrocinnamaldehyde (HCAL) with high selectivity of 98.9% and 99.5%, respectively. Our concept of restructured surface states to tune the chemoselectivity of α, β-unsaturated aldehydes triggered by the selective adsorption of alien molecules may lead to new design principles of heterogeneous catalysts, beyond the conventional d-band theory.</p>

scholarly journals Surface Molecule Manipulated Pt/TiO2 Catalysts for Selective Hydrogenation of Cinnamaldehyde

2021 ◽  
Author(s):  
Bing-Qian Shan ◽  
Ran Tao ◽  
Kun Zhang
Keyword(s):  
Selective Hydrogenation ◽  
Heterogeneous Catalysts ◽  
Selective Adsorption ◽  
Surface States ◽  
Solid Material ◽  
Sodium Formate ◽  
Band Theory ◽  
Saturated Aldehyde ◽  
Fundamental Limitation

<p>Surface states—the electronic states emerging as a solid material terminates at a surface—are usually vulnerable to contaminations and defects. This fundamental limitation has prohibited systematic studies of the potential role of surface states in surface reactions and catalysis, especially in more realistic environments. Herein, we use selective hydrogenation of <a>cinnamaldehyde</a> (CAL) on <a>platinum-covered titanium oxide</a> (Pt@P25) as a prototype reaction, and show that the competitive exchange of extra-introduced species (sodium hydroxide and sodium formate) with spontaneously formed weak bound carbonate and bicarbonate anions at Pt NPs can reconstruct the surface states, which directs the preferred adsorption of the conjugated C=O and C=C double bonds of CAL, and consequently, results in highly efficient synthesis of unsaturated alcohol cinnamyl alcohol (COL) and saturated aldehyde hydrocinnamaldehyde (HCAL) with high selectivity of 98.9% and 99.5%, respectively. Our concept of restructured surface states to tune the chemoselectivity of α, β-unsaturated aldehydes triggered by the selective adsorption of alien molecules may lead to new design principles of heterogeneous catalysts, beyond the conventional d-band theory.</p>

First Principles Model for Electronic Properties of Non-Ideal Surfaces of Refractory Interstitial Alloys

1990 ◽  
Vol 193 ◽  
Author(s):  
A. L. Ivanovsky ◽  
V. A. Gubanov
Keyword(s):  
Electronic Properties ◽  
Chemical Properties ◽  
Surface States ◽  
High Symmetry ◽  
Metal Carbides ◽  
Band Theory ◽  
Refractory Compounds ◽  
Physico Chemical ◽  
Wide Scale

A unique set of physico-chemical properties of the implantation phases (transition metal carbides and nitrides) and their wide-scale application in production processes motivated an intensive research in the electronic properties of the phases [1, 2]. A great attention attaches recently to the study of specific features of the electronic surface states of refractory compounds, the role of the electronic states being decisive in the formation of adsorption, catalytic, emission and other characteristics of the compounds. Available calculations of the energy spectrum of the high-symmetry faces of some 3d-5d-metal carbides and nitrides performed with the use of the band theory methods [4, 5] made it possible to establish principal features peculiar to the formation of surface states for ideal systems.

Interfacial Hydroxyl Promotes the Reduction of 4 Nitrophenol by Ag-Based Catalysts Confined in Dendritic Mesoporous Silica Nanospheres

2020 ◽  
Author(s):  
Xiao-Dan Hu ◽  
Bingqian Shan ◽  
Ran Tao ◽  
Taiqun Yang ◽  
Kun Zhang
Keyword(s):  
Mesoporous Silica ◽  
Surface States ◽  
Selective Reduction ◽  
Solid Material ◽  
Silica Nanospheres ◽  
Band Theory ◽  
Spin Orbital ◽  
Static Electron ◽  
Intermediate Surface ◽  
Mesoporous Silica Nanospheres

Surface states—the electronic states emerging as a solid material terminates at a surface—are usually vulnerable to contaminations and defects. This fundamental limitation has prohibited systematic studies of the potential role of surface states in surface reactions and catalysis, especially in more realistic environments. We use the selective reduction of 4-Nitrophenol on silver-covered dendritic mesoporous silica nanospheres (DMSNs) as a prototype example, and show that the dynamic intermediate surface states (DISS) spatially formed by spin orbital coupling (SOC) in singly hydrated hydroxyl complex can significantly enhance the adsorption energy of both 4-Nitrophenol and BH4- anions, by promoting different directions of static electron transfer. The concept of DISS as an electron bath may lead to new design principles beyond the conventional d-band theory of heterogeneous catalysis.

Interfacial Hydroxyl Promotes the Reduction of 4 Nitrophenol by Ag-Based Catalysts Confined in Dendritic Mesoporous Silica Nanospheres

2020 ◽  
Author(s):  
Xiao-Dan Hu ◽  
Bingqian Shan ◽  
Ran Tao ◽  
Taiqun Yang ◽  
Kun Zhang
Keyword(s):  
Mesoporous Silica ◽  
Surface States ◽  
Selective Reduction ◽  
Solid Material ◽  
Silica Nanospheres ◽  
Band Theory ◽  
Spin Orbital ◽  
Static Electron ◽  
Intermediate Surface ◽  
Mesoporous Silica Nanospheres

Surface states—the electronic states emerging as a solid material terminates at a surface—are usually vulnerable to contaminations and defects. This fundamental limitation has prohibited systematic studies of the potential role of surface states in surface reactions and catalysis, especially in more realistic environments. We use the selective reduction of 4-Nitrophenol on silver-covered dendritic mesoporous silica nanospheres (DMSNs) as a prototype example, and show that the dynamic intermediate surface states (DISS) spatially formed by spin orbital coupling (SOC) in singly hydrated hydroxyl complex can significantly enhance the adsorption energy of both 4-Nitrophenol and BH4- anions, by promoting different directions of static electron transfer. The concept of DISS as an electron bath may lead to new design principles beyond the conventional d-band theory of heterogeneous catalysis.

scholarly journals Elucidating the Influence of Electric Fields toward CO2 Activation on YSZ (111)

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 271
Author(s):  
Nisa Ulumuddin ◽  
Fanglin Che ◽  
Jung-Il Yang ◽  
Su Ha ◽  
Jean-Sabin McEwen
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Heterogeneous Catalysts ◽  
Co2 Reduction ◽  
Total Density ◽  
Reverse Water Gas Shift ◽  
High Thermodynamic Stability ◽  
Shift Reaction ◽  
Water Gas

Despite its high thermodynamic stability, the presence of a negative electric field is known to facilitate the activation of CO2 through electrostatic effects. To utilize electric fields for a reverse water gas shift reaction, it is critical to elucidate the role of an electric field on a catalyst surface toward activating a CO2 molecule. We conduct a first-principles study to gain an atomic and electronic description of adsorbed CO2 on YSZ (111) surfaces when external electric fields of +1 V/Å, 0 V/Å, and −1 V/Å are applied. We find that the application of an external electric field generally destabilizes oxide bonds, where the direction of the field affects the location of the most favorable oxygen vacancy. The direction of the field also drastically impacts how CO2 adsorbs on the surface. CO2 is bound by physisorption when a +1 V/Å field is applied, a similar interaction as to how it is adsorbed in the absence of a field. This interaction changes to chemisorption when the surface is exposed to a −1 V/Å field value, resulting in the formation of a CO3− complex. The strong interaction is reflected through a direct charge transfer and an orbital splitting within the Olatticep-states. While CO2 remains physisorbed when a +1 V/Å field value is applied, our total density of states analysis indicates that a positive field pulls the charge away from the adsorbate, resulting in a shift of its bonding and antibonding peaks to higher energies, allowing a stronger interaction with YSZ (111). Ultimately, the effect of an electric field toward CO2 adsorption is not negligible, and there is potential in utilizing electric fields to favor the thermodynamics of CO2 reduction on heterogeneous catalysts.

scholarly journals Things go better with coke: the beneficial role of carbonaceous deposits in heterogeneous catalysis

2016 ◽  
Vol 6 (2) ◽  
pp. 363-378 ◽  
Author(s):  
C. H. Collett ◽  
J. McGregor
Keyword(s):  
Heterogeneous Catalysis ◽  
Heterogeneous Catalysts ◽  
Catalyst Deactivation ◽  
Catalytic Performance ◽  
Fischer Tropsch ◽  
Carbonaceous Deposits ◽  
Beneficial Role ◽  
Catalytic Processes

Carbonaceous deposits on heterogeneous catalysts are traditionally associated with catalyst deactivation. However, they can play a beneficial role in many catalytic processes, e.g. dehydrogenation, hydrogenation, alkylation, isomerisation, Fischer–Tropsch, MTO etc. This review highlights the role and mechanism by which coke deposits can enhance catalytic performance.

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