Light-metal hydrides, like MgH2, remain under scrutiny as prototypes for reversible H-storage materials. For MgH2, we assess hydrogen desorption/adsorption properties (enthalpy and kinetic barriers) for stepped, catalyst-doped surfaces occurring, e.g., from ball-milling in real samples. Employing density functional theory and simulated annealing in a slab model, we studied initial H2 desorption...

Various synthesis and rehydrogenation processes of lithium hydride (LiH) and magnesium amide (Mg(NH₂)₂) system with 8:3 molar ratio are investigated to understand the kinetic factors and effectively utilize the essential hydrogen desorption properties. For the hydrogen desorption with a solid-solid reaction, it is expected that the kinetic properties become worse by the sintering and phase sepa...

The rate of water desorption from PBX-9502, a formulation containing 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), is measured using temperature-programmed desorption and modeled using conventional kinetic modeling methods. The results of these studies show two stages of moisture release. At lower temperatures, the release is likely assisted by thermal expansion of the TATB and melting of the Ke...

We use a stochastic approach to show how Taylor dispersion is affected by kinetic processes of adsorption and desorption onto surfaces. A general theory is developed, from which we derive explicitly the dispersion coefficients of canonical examples such as Poiseuille flows in planar and cylindrical geometries, in both constant and sinusoidal velocity fields. These results open the way for the m...

in the present investigation, a novel adsorbent, ionic liquid modified magnetic nanoparticles (il-fe3o4), was successfully synthesized and characterized by ft-ir spectroscopy, thermogravimetric analysis (tga), xrd analysis, scanning electron microscopy (sem) and theory of brunauer, emmett, and teller (bet) for removal of reactive orange 122 (ro-122) from aqueous solutions. the effects of variou...

Ab initio molecular dynamics calculations of deuterium desorbing from Si(100) have been performed in order to monitor the energy redistribution among the hydrogen and silicon degrees of freedom during the desorption process. The calculations show that part of the potential energy at the transition state to desorption is transferred to the silicon lattice. The deuterium molecules leave the surfa...

Layered nanoscale amorphous solid films of methanol and ethanol undergo complete intermixing prior to the onset of measurable desorption at 120 K. This intermixing precedes and inhibits crystallization. Subsequent desorption of the film is described quantitatively by a kinetic model describing evaporation from a continuously mixed ideal binary liquid solution. This occurs at temperatures below ...

abstract herbicides are the main sources of soil and water pollution in paddy fields. herbicides mobility to the surface and ground water is a major concern for human health and the environment. it is, therefore, necessary to investigate their fate and their interactions in natural ecosystems. to meet this purpose, field experiments were conducted to measure kinetic of thiobencarb dissipation i...

We report the first six-dimensional quantum dynamical calculations of dissociative adsorption and associative desorption. Using a potential energy surface obtained by density functional theory calculations, we show that the initial decrease of the sticking probability with increasing kinetic energy in the system H2/Pd(100), which is usually attributed to the existence of a molecular adsorption ...

In this study, bimodal meso-porous silica (UVM-7) synthesized and fabricated amino silane modified supports were characterized by powder X-ray diffraction (XRD), N2 adsorption/desorption, transmission electron microscope (TEM), elemental analysis and titration. Capacity of CO2 capture on modified bimodal pore structure silica at 70°C was calculated using breakthrough curves; and it was found th...