Dihydrogen adsorption

The least strongly sorbed reactant in HDS processes is dihydrogen. It could well be that the major reason for rate reduction by inhibitors is prevention of dihydrogen adsorption by competing molecules. This would include the sulfur-containing reactant as well. This would explain the phenomenon of self-inhibition in HDS reactions. 

A. Detection oe Adsorbed Species and Intermediates on Catalyst Surfaces A.I. Dihydrogen Adsorption... 

One way to explain the observed reaction orders is to also allow for a noncompetitive dihydrogen adsorption step in the sequence. This added complexity makes sense because more surface sites are available to dihydrogen than ethylene because of the very small size of a H2 molecule. The catalytic cycle for ethylene... 

The INS spectrum of hydrogen adsorbed by Raney palladium at 400 mbar corresponded to a mixture of p-PdH (480 cm ) and a-PdH (565 cm ) [27]. After dihydrogen adsorption at a lower pressure, 2 mbar, the INS showed peaks due both to the palladium hydrides and to adsorbed hydrogen. A broad peak at 975 cm" was assigned to the two unresolved vibrations of three-coordinated (Csv) hydrogen [27]. 

Y. Zhao, A.C. Dillon, Y.H. Kim, M.J. Heben and S.B. Zhang, Self-catalyzed hydrogenation and dihydrogenation adsorption on titanium carbide nanoparticles . 

DRIFT study of dinitrogen and dihydrogen adsorption on Li- and Na- forms of LSX zeolite... 

Cabon tetrachloride, n-hexane, chloroform, ACN, acetone, THF, pyridine, acetic acid, and their various mixtures were applied as mobile phases for adsorption TLC. Methanol, 1-propanol, ACN, acetone, THF, pyridine and dioxane served as organic modifiers for RP-TLC. Distilled water, buffers at various pH (solutions of and dipotassium hydrogen phosphate or potassium dihydrogen phosphate) and solutions of lithium chloride formed the aqueous phase. Carotenoids were extracted from a commercial paprika sample by acetone (lg paprika shaken with 3 ml of acetone for 30 min), the solution was spotted onto the plates. Development was carried out in a sandwich chamber in the dark and at ambient temperature. After development (15 cm for normal and 7cm for HPTLC plates) the plates were evaluated by a TLC scanner. The best separations were realized on impregnated diatomaceous earth stationary phases using water-acetone and water-THF-acetone mixtures as mobile phases. Some densitograms are shown in Fig.2.1. Calculations indicated that the selectivity of acetone and THF as organic modifiers in RP-TLC is different [14],... 

Divinylbenzene-polystyrene resins modified chemically, milled and screened to 30-45 micron and then packed by the authors 200 x 22 mm Aqueous disodium hydrogen phosphate, monopotassium dihydrogen phosphate and sodium chloride pH 2.8 temperature at 20, 30 or 40° C. 0.5,1.0, or 1.5 Aspartic acid, asparagine, phenylalanine, aspartame (theoretical adsorption study) 76... 

Choline bromide succinate, 998 Choline chloride, 466 Choline chloride carbamate, 427 Choline chloride succinate, 998 Choline citrate, 466 Choline dihydrogen citrate, 466 Choline salicylate, 965 Choline theophyllinate, 1011 Cholinesterase activity, assay kit, 1171 quantification in serum, 23 test for inhibition of, 6 Chondodendron tomentosum, 1057 Chromatographic performance, evaluation of, 189 Chromatography, adsorption, 204... 

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