In-Situ Spectroscopic Detection of Active Surface Species in Asymmetric Heterogeneous Catalysis

ChemCatChem ◽  
2013 ◽  
Vol 5 (3) ◽  
pp. 683-685 ◽  
Author(s):  
Guillaume Goubert ◽  
Peter H. McBreen
Keyword(s):  
Heterogeneous Catalysis ◽  
Active Surface ◽  
Surface Species ◽  
Asymmetric Heterogeneous Catalysis

Identification of Active Surface Species for Friedel-Crafts Acylation and Koch Carbonylation Reactions by in situ Solid-State NMR Spectroscopy

2013 ◽  
Vol 125 (19) ◽  
pp. 5242-5245 ◽  
Author(s):  
Inés Lezcano-González ◽  
José A. Vidal-Moya ◽  
Mercedes Boronat ◽  
Teresa Blasco ◽  
Avelino Corma
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Active Surface ◽  
Surface Species ◽  
Solid State Nmr Spectroscopy ◽  
Koch Carbonylation

scholarly journals Identification of Active Surface Species in Molten Carbonates Using in situ Raman Spectroscopy

2021 ◽  
Vol 9 ◽  
Author(s):  
Peng Zhang ◽  
Tao Wu ◽  
Kevin Huang
Keyword(s):  
Raman Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Active Surface ◽  
Active Species ◽  
Surface Species ◽  
In Situ Raman Spectroscopy ◽  
Functional Theory ◽  
Temperature Time

Here we report the results of a study on active surface species of a pristine and modified (Li-Na)2CO3 eutectic using in situ Raman spectroscopy technique. The effects of gas compositions, temperature, time, and alkaline earth have been systematically studied. The species of CO42–, HCO4–, and C2O52– are identified as the three major active species on the surface of (Li-Na)2CO3 eutectic by a combined Raman spectroscopy and theoretical density functional theory calculations. The results further reveal that CO42–, HCO4–, and C2O52– are preferably formed in the presence of O2, H2O, and high CO2 concentration. With the addition of Ba to the pristine (Li-Na)2CO3 eutectic, the Raman CO42–/HCO4– shifts become more pronounced.

In situ construction of phenanthroline-based cationic radical porous hybrid polymers for metal-free heterogeneous catalysis

2021 ◽  
Vol 9 (12) ◽  
pp. 7556-7565
Author(s):  
Guojian Chen ◽  
Yadong Zhang ◽  
Ke Liu ◽  
Xiaoqing Liu ◽  
Lei Wu ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Heterogeneous Catalysts ◽  
Hybrid Polymers ◽  
Metal Free ◽  
Oxidation Of Sulfides

Constructing phenanthroline-based cationic radical porous hybrid polymers as versatile metal-free heterogeneous catalysts for both oxidation of sulfides and CO2 conversion.

Surface Species Formed during Aniline Methylation on Zeolite H–Y Investigated by in Situ MAS NMR Spectroscopy

2001 ◽  
Vol 203 (2) ◽  
pp. 375-381 ◽  
Author(s):  
Irina I Ivanova ◽  
Elena B Pomakhina ◽  
Alexander I Rebrov ◽  
Michael Hunger ◽  
Yuryi G Kolyagin ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Mas Nmr ◽  
Surface Species

Homochiral Metal–Organic Frameworks for Asymmetric Heterogeneous Catalysis

2011 ◽  
Vol 112 (2) ◽  
pp. 1196-1231 ◽  
Author(s):  
Minyoung Yoon ◽  
Renganathan Srirambalaji ◽  
Kimoon Kim
Keyword(s):  
Heterogeneous Catalysis ◽  
Metal Organic Frameworks ◽  
Metal Organic ◽  
Asymmetric Heterogeneous Catalysis

Mechanistic Insights into the Spontaneous Reaction Between CO2 and La2-xSrxCuO4

2021 ◽  
Author(s):  
Alexander William Henry Whittingham ◽  
Jordan Lau ◽  
Rodney David Lucien Smith
Keyword(s):  
Electrochemical Impedance ◽  
Co2 Reduction ◽  
Active Surface ◽  
Structural Instability ◽  
Redox Couple ◽  
Surface Sites ◽  
Carbonate Ions ◽  
Redox Active ◽  
Spontaneous Reaction

Layered perovskites such as La2-xSrxCuO4 are active electrocatalysts for CO2 reduction, but they suffer from structural instability under catalytic conditions. This structural instability is found to arise from the reaction of CO2 with surface sites. Variable scan rate voltammetry shows the growth of a Cu-based redox couple when potentials cathodic of 0.6 V vs. RHE are applied in the presence of CO2. Electrochemical impedance spectroscopy identifies a redox active surface state at this voltage, whose concentration is increased by electrochemical reduction in the presence of CO2. In-situ spectroelectrochemical FTIR identifies surface bound carbonates as being involved formation of these surface sites. The orthorhombic lattice for La2-xSrxCuO4 is found to uniquely enable monodentate binding of (bi)carbonate ions from solution as well as bidentate carbonate ions through reaction with CO2. The incorporation of Sr(II) induces a transition to a tetragonal lattice, for which only monodentate carbonate ions are observed. It is proposed that the binding of carbonate ions in a bidentate fashion generates sufficient strain at the surface to result in amorphization at the surface, yielding the observed Cu(II)/Cu(I) redox couple.

In situ identification of surface species on molybdenum in different media

1998 ◽  
Vol 43 (16-17) ◽  
pp. 2459-2467 ◽  
Author(s):  
Kang Wang ◽  
Ying-Sing Li ◽  
Peixin He
Keyword(s):  
Surface Species
Sign in / Sign up

Export Citation Format

Share Document