Adsorption Of Hydrazine Research Articles

ラジオ波放電により生成したヒドラジンのゼオライトへの吸着

The adsorption of hydrazine formed in a nitrogen-hydrogen plasma prepared using radiofrequency discharge on sodium ion-exchanged zeolite (NaZ) or hydrogen ion-exchanged zeolite (HZ) was, studied. Although the adsorbed amount of hydrazine was two orders of magnitude less than that of ammonia, a hundred times larger amounts of hydrazine could be adsorbed on HZ than on NaZ (Table 1). Larger amounts of acidic sites on HZ would contribute to an increment of the amount of hydrazine adsorbed.

Hydrazine adsorption and the coadsorption of CO and D 2 with nitrogen atoms on Rh(100)

Abstract The adsorption and decomposition of hydrazine on Rh(100) has been studied by thermal desorption, X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. Molecular hydrogen, ammonia, molecular nitrogen and hydrazine desorbed from multilayers of adsorbed hydrazine. At temperatures between 500 and 550 K, atomic nitrogen was the only species remaining on the surface. The coadsorption of carbon monoxide and deuterium with various coverages of this atomic nitrogen has been investigated. The presence of nitrogen reduced the sticking coefficient of deuterium, shifted the adsorbed deuterium into more weakly held sites, and lowered the saturation coverage. The metal-carbon monoxide bond was weakened by the presence of atomic nitrogen. Using photoelectron spectroscopies, no new surface species, formed from the interaction of carbon monoxide with atomic nitrogen, were detected.

Hydrazine adsorption and the coadsorption of CO and D 2 with nitrogen atoms on Rh(100)

The adsorption and decomposition of hydrazine on Rh(100) has been studied by thermal desorption, X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. Molecular hydrogen, ammonia, molecular nitrogen and hydrazine desorbed from multilayers of adsorbed hydrazine. At temperatures between 500 and 550 K, atomic nitrogen was the only species remaining on the surface. The coadsorption of carbon monoxide and deuterium with various coverages of this atomic nitrogen has been investigated. The presence of nitrogen reduced the sticking coefficient of deuterium, shifted the adsorbed deuterium into more weakly held sites, and lowered the saturation coverage. The metal-carbon monoxide bond was weakened by the presence of atomic nitrogen. Using photoelectron spectroscopies, no new surface species, formed from the interaction of carbon monoxide with atomic nitrogen, were detected.

Adsorption and decomposition of hydrazine on metal films of iron, nickel, and copper

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAdsorption and decomposition of hydrazine on metal films of iron, nickel, and copperYousif K. Al-Haydari, Jalal Mohammed Saleh, and Mohammed H. MatloobCite this: J. Phys. Chem. 1985, 89, 15, 3286–3290Publication Date (Print):July 1, 1985Publication History Published online1 May 2002Published inissue 1 July 1985https://doi.org/10.1021/j100261a024RIGHTS & PERMISSIONSArticle Views342Altmetric-Citations36LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (576 KB) Get e-Alerts

Adsorption of hydrazine and ammonia on aluminium

The adsorption and decomposition of hydrazine and ammonia by clean polycrystalline aluminium surfaces have been studied by X-ray photoelectron spectroscopy. At 85 K both ammonia and hydrazine are adsorbed molecularly, with N(1 s) peaks at 400.5 eV. At 290 K hydrazine is initially adsorbed to give an N(1 s) peak at about 399 eV, but with time (and further exposure) the position of the peak maximum drift to lower N(1 s) values, finally approaching 397 eV after heating the ad-layer to 390 K. These observations are interpreted in terms of a slow dissociative chemisorption process: N 2H 4(a) → NH 2(a) → NH(a) → N(a). There is no doubt that the NN bond in hydrazine is broken and that hydrogen ad-atoms formed inhibit the subsequent adsorption of N 2H 4 at 290 K. Ammonia dissociates more slowly than hydrazine to give mainly amine (NH 2) species at 290 K.

The manganic hydroxide–hydrazine system as an initiator of vinyl polymerization. IV. The emulsion polymerization of methyl methacrylate

The behavior of the emulsifier sodium dodecyl sulfate and electrolyte sodium hydroxide was studied at the oxidation stage and beyond in the emulsion polymerization of methyl methacrylate initiated by the manganic hydroxide–hydrazine hydrate system. From the rate of polymerization and from the adsorption of hydrazine it was shown that addition of emulsifier is more effective at the oxidation stage than after. But the reverse is obtained with the electrolyte. The effect of hydrazine concentration was also studied. The results are explained on the basis of a surface reaction between hydrazine hydrate and the insoluble manganic hydroxide.

The interaction of hydrazine with an Fe(111) surface

The interaction of hydrazine with a clean and nitrogen precovered Fe(111) surface was investigated in the temperature range of 126–600 K by means of UV and X-ray photoelectron spectroscopy (PES). At temperatures below 170 K the molecular adsorption of hydrazine is followed by multilayer condensation. In going from adsorbed to condensed hydrazine the valence and core levels shift in different directions relative to the vertical gas phase ionisation energies indicating strong interactions via hydrogen bonding in the condensed phase. Dissociative adsorption of N 2H 4 was observed at temperatures above 220 K. At room temperature no difference in the photoelectron spectra following the adsorption of N 2H 4 or NH 3 was observed indicating the presence of the same surface species, predominantly being -NH 2 radicals. Preadsorbed nitrogen stabilizes N 2H 4 against decomposition. The results will be discussed in view of possible intermediates in the ammonia-synthesis reaction on iron. Simple thermochemical arguments are presented to explain the observed difference in the heterogeneous dissociation mechanism of hydrazine on transition metals. General conclusions on the mechanism of ammonia synthesis on various transition metals can also be derived from these thermodynamic considerations.

Hydrazine decomposition over a supported iridium catalyst

Adsorption and desorption of hydrazine and its decomposition products (H 2, N 2, NH 3) on an indium alumina catalyst have been studied by temperature programmed desorption and ir spectroscopy in order to determine the mechanism of the decomposition and the nature of the active centers. Hydrogen is chemisorbed on two types of adsorption sites. Activation energies of desorption have been calculated for these sites and they are 10.5 and 25 kcal mole −1. Sites of lower energy are attributed to the existence of an Ir-alumina complex and these of higher energy to bulk iridium. Nitrogen is not adsorbed from the gaseous phase between 25 and 700 °C. Ammonia is adsorbed on metal and alumina at room temperature, its decomposition begins at 200 °C. Desorption spectra, recorded after adsorbing and decomposing hydrazine, show a new desorption peak, which is attributed to nitrogen remaining adsorbed on iridium. It corresponds to a desorption activation energy of 14 kcal mole −1, and it confirms that the first step of decomposition is the formation of a bond between the nitrogen atoms of the hydrazine molecule and the unfilled d orbitals of the metal. Apparently, at 300 °K, the decomposition is carried out according to the reaction 3N 2H 4 → 4NH 3 + N 2. The ir spectra of ammonia and hydrazine adsorbed on the catalyst exhibit a band at 1220 cm −1, besides the adsorption bands characteristic of ammonia adsorbed on alumina; this band could be attributable to ammonia chemisorbed on iridium.