The Potential-pH Diagrams Depicting the Hydrogen Chemisorption in the Pt-H2O, Ir-H2O, and Rh-H2O Systems at 25 °C

1995 ◽  
Vol 60 (4) ◽  
pp. 553-558 ◽  
Author(s):  
Tomáš Loučka
Keyword(s):  
Thermodynamic Data ◽  
Hydrogen Chemisorption

Thermodynamic data for the chemisorption of hydrogen on the Pt, Ir, and Rh electrodes were evaluated from data in the literature. On the basis of these data, the potential-pH diagrams were calculated for the Pt-H2O, Ir-H2O, and Rh-H2O systems describing the hydrogen chemisorption. For the hydrogen chemisorption, the surface was considered to be uniformly inhomogeneous.

The Potential-pH Diagram Depicting the Chemisorption of Two Species on the Uniformly Inhomogeneous Surface. The Sulfur and Hydrogen Chemisorption on the Platinum Electrode

1995 ◽  
Vol 60 (7) ◽  
pp. 1101-1108 ◽  
Author(s):  
Tomáš Loučka
Keyword(s):  
Thermodynamic Data ◽  
Platinum Electrode ◽  
Hydrogen Chemisorption ◽  
Inhomogeneous Surface

General thermodynamic dependences were derived for the simultaneous chemisorption of two substances on the uniformly inhomogeneous surface. In terms of these dependences and on the basis of thermodynamic data available in the literature, the potential-pH diagram was calculated for the Pt-S-H2O system at 25 °C on considering the sulfur and hydrogen chemisorption.

Adsorption and corrosion inhibition characteristics of two medicinal molecules

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Half Life ◽  
Thermodynamic Data ◽  
Inhibition Efficiency ◽  
Gravimetric Method ◽  
Corrosive Environment ◽  
Corrosion Inhibition Efficiency

The corrosion inhibition characteristics of two medicinal molecules phenylalanine and rutin on mild steel in 1.0M Hydrochloric acid were evaluated using gravimetric method. Corrosion inhibition efficiency of 83.78 and 90.40 % was obtained respectively after seven days. However, phenylalanine showed weak accumulative higher corrosion inhibition efficiency. The presence of both molecules in the corrosive environment reduced the corrosion rate constant and increased the material half-life. Thermodynamic data calculated suggests a spontaneous adsorption of the molecules on the mild steel’s surface.

Thermodynamic Data of Iodine Reactions Calculated by Quantum Chemistry. Training Set of Molecules

2008 ◽  
Vol 73 (10) ◽  
pp. 1340-1356 ◽  
Author(s):  
Katarína Mečiarová ◽  
Laurent Cantrel ◽  
Ivan Černušák
Keyword(s):  
Quantum Chemistry ◽  
Ab Initio ◽  
Thermodynamic Data ◽  
Theoretical Calculations ◽  
Reactor Core ◽  
Fission Products ◽  
Vapour Phase ◽  
Reactor Accident ◽  
Training Set ◽  
Coolant System

This paper focuses on the reactivity of iodine which is the most critical radioactive contaminant with potential short-term radiological consequences to the environment. The radiological risk assessments of 131I volatile fission products rely on studies of the vapour-phase chemical reactions proceeding in the reactor coolant system (RCS), whose function is transferring the energy from the reactor core to a secondary pressurised water line via the steam generator. Iodine is a fission product of major importance in any reactor accident because numerous volatile iodine species exist under reactor containment conditions. In this work, the comparison of the thermodynamic data obtained from the experimental measurements and theoretical calculations (approaching "chemical accuracy") is presented. Ab initio quantum chemistry methods, combined with a standard statistical-thermodynamical treatment and followed by inclusion of small energetic corrections (approximating full configuration interaction and spin-orbit effects) are used to calculate the spectroscopic and thermodynamic properties of molecules containing atoms H, O and I. The set of molecules and reactions serves as a benchmark for future studies. The results for this training set are compared with reference values coming from an established thermodynamic database. The computed results are promising enough to go on performing ab initio calculations in order to predict thermo-kinetic parameters of other reactions involving iodine-containing species.

Modelling the thermodynamic data for hcp Zn and Cu–Zn alloys– an ab initio and calphad approach

Calphad ◽  
2021 ◽  
Vol 72 ◽  
pp. 102253
Author(s):  
Alan Dinsdale ◽  
Alexandra Khvan ◽  
Ekaterina A. Smirnova ◽  
Alena V. Ponomareva ◽  
Igor A. Abrikosov
Keyword(s):  
Ab Initio ◽  
Thermodynamic Data ◽  
Calphad Approach ◽  
Zn Alloys

scholarly journals Novel hydrogen chemisorption properties of amorphous ceramic compounds consisting of p-block elements: exploring Lewis acid-base Al–N pair site formed in-situ within polymer-derived silicon-aluminum-nitrogen-based system

2021 ◽  
Author(s):  
Shotaro Tada ◽  
Norifumi Asakuma ◽  
Shiori Ando ◽  
Toru Asaka ◽  
Yusuke Daiko ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Active Site ◽  
Hydrogen Chemisorption ◽  
Acid Base ◽  
Polymer Derived Ceramics ◽  
System P ◽  
Ceramic Compounds ◽  
The Relationship

This paper reports on the relationship between the H2 chemisorption properties and reversible structural reorientation of the possible active site around Al formed in-situ within polymer-derived ceramics (PDCs) based on...

Thermodynamics of Protonation and Sodium Binding of Sulfate in Concentrated NaCl and CsCl Solutions Studied by Raman Spectroscopy

2000 ◽  
Vol 53 (5) ◽  
pp. 363 ◽  
Author(s):  
Steven Kratsis ◽  
Glenn Hefter ◽  
Peter M. May ◽  
Pal Sipos
Keyword(s):  
Raman Spectroscopy ◽  
Excellent Agreement ◽  
Thermodynamic Data ◽  
Association Constant ◽  
Protonation Constant ◽  
Ion Pairing ◽  
Ion Pair ◽  
Enthalpy And Entropy Changes ◽  
Enthalpy And Entropy ◽  
Sodium Binding

The protonation constant (pKa) of SO42–(aq) has been determined at ionic strengths 0.5 M ≤I ≤4.0 M in NaCl and CsCl media at 25˚C by using Raman spectroscopy. These data were used to calculate the association constant of the NaSO4–(aq) ion pair in CsCl media. The results are in excellent agreement with previous values obtained by other techniques. The (pKa) was also measured at I = 4 M in both media at temperatures up to 85˚C and the associated enthalpy and entropy changes were calculated. However, reliable thermodynamic data for the ion-pairing reaction could not be obtained at higher temperatures probably because of competition from CsSO4–(aq).

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