Spectral studies on sulfur poisoning of Pd/Mg6Ni by NEXAFS and XPS

Yagi, Shunsuke; Nambu, Masao; Tsukada, Chie; Ogawa, Soichi; Kutluk, G.; Namatame, H.; Takeuchi, Masaki

doi:10.1016/j.apsusc.2012.05.098

Cited by 12 publications

(3 citation statements)

References 21 publications

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“…It reveals three peaks in the modified adsorbent located at163.2 eV, 163.8 eV, and 168.0 eV, which can be attributed to chemisorption as a result of the covalent bonding between thiols and neutral As(III) species. These three peaks correspond to methanethiolate (CH 3 S-), chemisorbed dimethyl sulfide ((CH 3 ) 2 S) and sulfate (SO 4 2- ) [ 36 ]. Since the intensity of the (CH 3 ) 2 S peak became weaker than the CH 3 S peak after As adsorption, the methyl groups might exchange with arsenic.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Adsorption of Trivalent Arsenic from Water by Functionalized Diatom Silica Shells

et al. 2015

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The potential of porous diatom silica shells as a naturally abundant low-cost sorbent for the removal of arsenic in aqueous solutions was investigated in a batch study. The objective of this work was to chemically modify the silica shells of a diatom Melosira sp. with bifunctional (thiol and amino) groups to effectively remove arsenic in its toxic As(III) form (arsenite) predominant in the aquatic environment. Sorption experiments with this novel sorbent were conducted under varying conditions of pH, time, dosage, and As(III) concentration. A maximum adsorption capacity of 10.99 mg g-1 was achieved within 26 h for a solution containing 12 mg L-1 As(III) at pH 4 and sorbent dosage of 2 g L-1. The functionalized diatom silica shells had a surface morphological change which was accompanied by increased pore size at the expense of reduced specific surface area and total pore volume. As(III) adsorption was best fitted with the Langmuir-Freundlich model, and the adsorption kinetic data using pore surface diffusion model showed that both the external (film) and internal (intraparticle) diffusion can be rate-determining for As(III) adsorption. Fourier transform infrared spectroscopy (FTIR) indicated that the thiol and amino groups potentially responsible for As(III) adsorption were grafted on the surface of diatom silica shells. X-ray photoelectron spectroscopy (XPS) further verified that this unique sorbent proceeded via a chemisorption mechanism through the exchange between oxygen-containing groups of neutral As(III) and thiol groups, and through the surface complexation between As(III) and protonated nitrogen and hydroxyl groups. Results indicate that this functionalized bioadsorbent with a high As(III) adsorption capacity holds promise for the treatment of As(III) containing wastewater.

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Section: Resultsmentioning

confidence: 99%

Enhanced Adsorption of Trivalent Arsenic from Water by Functionalized Diatom Silica Shells

et al. 2015

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“…The photoelectrons issued from the ionization of target atoms are selected in kinetic energy by passing through an analyzer and the collected signal is then notably amplified by the presence of five Channeltron detectors [18][19][20][21]. The binding energy (BE) of the C1s level at 284.80 eV was used as an internal reference to calibrate every spectrum.…”

Section: Tg/dsc and X-ray Photoelectron Spectroscopy (Xps) Studymentioning

confidence: 99%

Study of Hg0 removal characteristics on Fe2O3 with H2S

Liu

Xue

Guo

2015

Fuel

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“…Sulfur poisoning can result in adverse impacts on the performance of the catalyst, such as deactivation and deteriorated catalytic selectivity [11]. There are a number of studies on the sulfur poisoning effect of catalysts in gas-phase reactions such as methane oxidation and hydrocarbon hydrogenation [12][13][14][15][16]. However, the poisoning of catalysts by sulfur in liquid systems (e.g., aqueous and organic solvents) has not been reported and its mechanism is largely unknown.…”

Section: Introductionmentioning

confidence: 99%

Site-selective sulfurization of bromide-capped palladium nanocubes by polysulfide and the underlying mechanism

Lü

Wang

et al. 2013

Nanotechnology

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This article describes site-selective sulfurization of Pd nanocubes capped by a monolayer of chemisorbed Br(-) ions. High-resolution transmission electron microscopy and high-angle annular dark-field scanning TEM observations showed that PdS was not formed until a certain quantity of polysulfide (S(x)(2-)) ions had been introduced (300 μl, or 18.8 ppm in the final reaction solution). Spot energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy analyses confirmed that the surface-chemisorbed Br(-) ions were completely substituted by S(x)(2-) ions before the initiation of the sulfurization reaction. In the presence of sufficient S(x)(2-) ions (>300 μl or >18.8 ppm), PdS phase was selectively developed from the highly active corners, which then moved to the edges and finally towards the center until the entire nanocube was converted into PdS. The resultant PdS was found to be amorphous by electron microscopy and powder x-ray diffraction measurements. The amorphous structure of PdS facilitated the penetration and diffusion of S(x)(2-) species and thus acceleration of the reaction kinetics. As a result, the sulfurization of 13 nm Pd nanocubes was completed within a few minutes after the addition of adequate Na2Sx, leading to a much more severe poisoning effect, compared with other noble metals such as Ag, by sulfur.

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Spectral studies on sulfur poisoning of Pd/Mg6Ni by NEXAFS and XPS

Cited by 12 publications

References 21 publications

Enhanced Adsorption of Trivalent Arsenic from Water by Functionalized Diatom Silica Shells

Enhanced Adsorption of Trivalent Arsenic from Water by Functionalized Diatom Silica Shells

Study of Hg0 removal characteristics on Fe2O3 with H2S

Site-selective sulfurization of bromide-capped palladium nanocubes by polysulfide and the underlying mechanism

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