Adsorption of water vapors and the micropore structure of carbon adsorbents. Communication 9. The nature of the primary adsorption sites

1984 ◽  
Vol 33 (7) ◽  
pp. 1331-1335
Author(s):  
R. Sh. Vartapetyan ◽  
A. M. Voloshchuk ◽  
M. M. Dubinin
Keyword(s):  
Carbon Adsorbents ◽  
Micropore Structure ◽  
Adsorption Sites ◽  
Water Vapors ◽  
Adsorption Of Water

The mechanism of the adsorption of water molecules on carbon adsorbents

1995 ◽  
Vol 64 (11) ◽  
pp. 985-1001 ◽  
Author(s):  
R Sh Vartapetyan ◽  
A M Voloshchuk
Keyword(s):  
Carbon Adsorbents ◽  
Water Molecules ◽  
Adsorption Of Water

Water Adsorption on Ideal Anatase-TiO2(101) – An Embedded Cluster Model for Accurate Adsorption Energetics and Excited State Properties

2020 ◽  
Vol 234 (5) ◽  
pp. 813-834 ◽  
Author(s):  
Thorben Petersen ◽  
Thorsten Klüner
Keyword(s):  
Excited State ◽  
Cluster Model ◽  
Dissociative Adsorption ◽  
Molecular Adsorption ◽  
Hydrogen Electrode ◽  
Adsorption Sites ◽  
First Results ◽  
Adsorption Of Water ◽  
Hybrid Functionals ◽  
High Level

AbstractA combined theoretical approach towards the accurate description of water on anatase-TiO2(101) was pursued in this study. Firstly, periodic slab calculations on the basis of density hybrid functionals (PBE0, HSE06) were performed in order to gain insight into the adsorption sites and geometric structure of the surface. For submonolayer coverage of H2O, the molecular adsorption of water is found to be the most stable one with quite similar energetics in PBE0 and HSE06. Moreover, the transition states towards the less preferred dissociative adsorption forms are predicted to be greater than 0.7 eV. Thus, water will not spontaneously dissociate and based on the Computational Hydrogen Electrode model an overpotential of about 1.71 V is needed to drive the overall oxidation. In addition, to validate our results for molecular adsorption of H2O, an embedded cluster model is carefully evaluated for the a-TiO2(101) surface based on the periodic slab calculations. Subsequent high-level DLPNO-CCSD(T) results are in close agreement with our periodic slab calculations since the interaction is found to mainly consist of electrostatic contributions which are captured by hybrid functionals. Finally, first results on optimized geometries in the excited state based on the photogenerated charge-transfer state are presented.

Chemisorption of Ammonia on Silica

1973 ◽  
Vol 51 (11) ◽  
pp. 1771-1781 ◽  
Author(s):  
G. A. Blomfield ◽  
L. H. Little
Keyword(s):  
Adsorption Process ◽  
Ammonia Adsorption ◽  
Adsorption Sites ◽  
Added Water ◽  
Adsorption Of Water ◽  
Amine Groups

The interaction of ammonia with silicas prepared by a variety of methods was studied to resolve conflicting reports of the mode of ammonia adsorption and to determine the role of chlorine impurities (present in the silica) in the adsorption process. Results for the adsorption of water on silica assisted in making band assignments and competition between ammonia and water for silica adsorption sites was observed. It was concluded that dehydroxylated silicas contain sites which dissociate ammonia to form Si—NH2 groups having infrared bands at 3540, 3450, and 1550 cm−1 (the surface amine groups are not displaced by added water). The presence of chlorine in the silica is not a prerequisite for chemisorption of ammonia.

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