Adsorption sites
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Zr-based metal-organic frameworks (Zr-MOFs) are emerging as potential adsorbents for removing nitrogen contaminants in fuel and wastewater. Functionalized Zr-MOFs exhibited superior indole (IND) adsorption capacity than the original MOF, but the activity of the multiple adsorption sites has not been discussed.
9p visergeyne 18-06-2024 2 0 Download
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Hydrogen bonding on two-dimensional silicon carbide (2D SiC) was studied using molecular dynamics and ab initio calculations. By investigating a converged density functional theory (DFT) calculation, the stable bonding sites of a hydrogen atom on the 2D SiC were found at the top sites (TSi and TC, of which TSi is a more stable adsorption site).
8p vijeff 30-11-2023 3 2 Download
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The adsorption of toxic gas molecules on Xenes (X = Si, Ge, Sn) has been studied by density functional theory (DFT). The optimized adsorption site of the adsorbates (CO, CO2, NO2) on Xenes (X = Si, Ge, Sn), the corresponding adsorption energies, band gap, band structure, and density of states of silicene, germanene, and stanene are discussed.
15p visharma 20-10-2023 6 2 Download
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CO adsorption on the Cu(211) surface was investigated using energy, geometry and vibrational data, which were produced through periodic DFT computations. Adsorption on the (111) terrace, as well as the previously reported top and bridge sites of the stepedges, was studied at 0.25, 0.33, 0.50, 0.66, 0.75, and 1.00 monolayer (ML) CO coverage. Results showed that up to and including 0.50 ML, on-top or bridge adsorption is preferred on the step-edges.
13p lyhuyenthu 31-01-2023 3 2 Download
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GO-NH2 (amino functionalized graphene oxide) was synthesized by grafting (3-aminopropyl) triethoxysilane onto the surface GO (graphene oxide). The GO-NH2with a higher surface area and many active sites was characterized and its effectiveness in removing Rhod B dye and Ni(II) ions from wastewater by adsorption was observed. The effects of pH, time, and strange ions on the adsorption efficiency were investigated.
17p lyhuyenthu 31-01-2023 8 2 Download
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The influence of heterogeneity, however, cannot be studied experimentally. In this study, we employed two reversed phase columns with different retention mechanisms to show that by serially coupling the columns, the obtained thermodynamic parameters are not related to the results obtained on the respective individual columns.
7p viginny 23-12-2022 5 3 Download
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Analysis of multiple equilibria of compounds with different coordination sites is extended to the description of adsorption isotherms with focus on the low relative pressure range. The entropy evolution is described using the particle distribution theory which also holds for adsorbents consisting of materials bearing more than one type of sites and applies for the condition that the adsorptive-adsorbent binding strength is larger than the adsorptiveadsorbate binding strength, so that monolayer coverage is favored.
12p vironald 15-12-2022 4 2 Download
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Efficient CO2 capture is necessary to solve the current environmental problems of global warming. Porous materials are promising for this purpose and adsorption capacity is a critical issue. Large cations in zeolites can often attach two small molecules, but it is not yet well established whether this applies to CO2.
10p vironald 15-12-2022 8 2 Download
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The surface of mesocellular silica foam (MCF) was modified by grafting 3-aminopropyl-triethoxysilane (APTES) to have a positive charge, and thus to provide sites for the immobilization of H3PW12O40(PW12). This modified nanosized mesoporous silica (PW12-APTES@MCF) was characterized by FTIR, XRD, BET, and TEM. XRD and adsorption–desorption analysis shows that the mesostructure of silica remains intact after various modifications, while the spectral technique shows the successful grafting of the neat PW12 inside the porous silica support.
9p langthannam 29-12-2021 8 0 Download
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NH3 adsorption and desorption behavior of a commercial Cu-chabazite (CHA) NH3 selective catalytic reduction (NH3 -SCR) catalyst was studied in the presence and absence of H2O. NH3 uptake values at various adsorption temperatures were obtained during various steps of the adsorption and temperature-programmed desorption (TPD) experiments. Total NH3 uptake decreased from 4.6 to 1.6 g NH3/L catalyst when the adsorption temperature was increased from 50 to 300◦C.
13p tudichquannguyet 29-11-2021 9 1 Download
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A series of alkylorganotin-based catalysts (Sn-g-C3N4/AC) was prepared by wet impregnation in ethanol using different g-C3N4 precursors and alkylorganotin compounds. The structure, texture, surface composition, and adsorption properties of the as-prepared catalysts were extensively characterized. Then, the obtained samples were evaluated for their catalytic performance in hydrochlorination of acetylene. The results provided by the X-ray photoelectron spectroscopy, acetylene temperature-programmed desorption, and HCl adsorption confirmed the nature of the active sites (i.e.
16p tudichquannguyet 29-11-2021 8 1 Download
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The physical and chemical properties of bimetallic nanoparticles can be optimized by tuning the particle composition. In this study, we identified CO adsorption and dissociation energetics on five Pt-Mo nanoparticles at different concentrations, the lowest energy Pt7, Pt6Mo, Pt5Mo2, Pt4Mo3, and Mo7 clusters. We have shown that the CO adsorption and dissociation energies and preferred CO adsorption sites are largely dependent on the composition of the nanoparticles.
20p tudichquannguyet 29-11-2021 5 1 Download
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A laboratory study was undertaken to investigate the P adsorption behavior of three representative soils of Chhattisgarh belonging to the order Inceptisol, Alfisol and Vertisol.
6p angicungduoc8 07-11-2020 13 1 Download
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Accelerated exploitation of oil and gas resources planned and implemented by ONGC and BGEIPL in west coast offshore region would result into stress particularly on marine environment. The long term physical, chemical and biological changes due to routine discharges from offshore installations can best be assessed through a study on accumulation of hydrocarbons and heavy metals in fishes, plankton and sediments which together form biotic and abiotic components of marine environment.
10p chauchaungayxua6 26-06-2020 15 2 Download
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Agricultural wastes are considered as viable alternatives because of their abundant availability, low cost and also with various functional groups such as carboxylic acid, ester, carboxylate, hydroxyl, phenolic and amino that can act as adsorption sites for heavy metal ion. Banana peel waste based biosorbents to remove cadmium from waste water was taken up for the present study.
14p nguaconbaynhay4 22-03-2020 11 0 Download
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The hydrogen vibration was investigated to analyze its affect on the hydrogen adsorption on the missing row platinum surface (H/Pt(110)-(1x2) model) in the ultrahigh vacuum (UHV). The density functional theory (DFT) combined with the approximation oscillation of the hydrogen atom on the surface was used. When the hydrogen coverage Θ H on the surface is 100% (Θ H = 1 ML), and taking into account the vibrational effect, the bond formed at the edge of the first layer (short bridge) is the most stable site. The vibrational effect on the adsorption model H/Pt(110)- (1x2) is significant.
8p 12120609 23-03-2020 13 0 Download
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The isotope effects of neodymium in Nd-glycolate ligand exchange system were studied by using ion exchange chromatography. The separation coefficients of neodymium isotopes, e’s, were calculated from the observed isotopic ratios at the front and rear boundaries of the neodymium adsorption band.
7p kethamoi1 17-11-2019 18 1 Download
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Individual and competitive adsorption studies were carried out to investigate the removal of phenol and nickel ions by adsorption onto multiwalled carbon nanotubes (MWCNTs). The carbon nanotubes were characterized by different techniques such as X-ray diffraction, scanning electron microscopy, thermal analysis and Fourier transformation infrared spectroscopy. The different experimental conditions affecting the adsorption process were investigated. Kinetics and equilibrium models were tested for fitting the adsorption experimental data.
11p trinhthamhodang1 16-11-2019 9 0 Download
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To investigate the H2 purification mechanism of V membranes, we studied the adsorption, dissociation, and diffusion properties of H in V, an attractive candidate for H2 separation materials. Our results revealed that the most stable site on the V (1 0 0) surface is the hollow site (HS) for both adsorbed H atoms and molecules. As the coverage range increases, the adsorption energy of H2 molecules first decreases and then increases, while that of H atoms remains unchanged.
10p trinhthamhodang1 14-11-2019 9 1 Download
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Catalytic oxidation of m-xylene was carried out over the copper oxide catalyst loaded on SiO2 300 m2/g. The various techniques were used to characterize the catalysts x-ray diffraction, TPRH2, N2 adsorption-desorption, scanning electron microscopy (SEM), tranmission electron microscopy (TEM) and CO pulse chemisorptions. The results indicate that the impregnated solution concentration exerts an influence on the catalytic activity.
6p uocvong01 24-09-2015 49 3 Download