Microkinetic modeling of the hydrogenation of nitrate in water on Pd–Sn/Al2O3 catalyst

Costa, Adagneves O.; Ferreira, Luciana S.; Passos, Fábio B.; Maia, Mônica P.; Peixoto, Fernando Cunha

doi:10.1016/j.apcata.2012.07.043

Cited by 13 publications

(31 citation statements)

References 36 publications

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“…Based on the prevailing mechanism for nitrate reduction with Pd-based catalysts, the first reduction intermediate is anticipated to be nitrite [32,82,83], and the fact that no nitrite intermediate is observed when monitoring nitrate reactions ( Fig. 2a) would suggest nitrite reduction is much faster than nitrate reduction at comparable conditions (similar to observations reported for Pd catalysts under most conditions [31,74,84]).…”

Section: Catalytic Nitrite Reductionsupporting

confidence: 72%

Hydrogenation of aqueous nitrate and nitrite with ruthenium catalysts

Huo

Hoomissen

Liu

et al. 2017

Applied Catalysis B: Environmental

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Historically, development of catalysts for treatment of nitrate-contaminated water has focused on supported Pd-based catalysts, but high costs of the Pd present a barrier to commercialization. As part of an effort to develop lower cost hydrogenation catalysts for water treatment applications, we investigated catalysts incorporating Ru with lower cost. Pseudo-first-order rate constants and turnover frequencies were determined for carbon-and alumina-supported Ru and demonstrated Ru's high activity for hydrogenation of nitrate at ambient temperature and H 2 pressure. Ex situ gas pretreatment of the catalysts was found to enhance nitrate reduction activity by removing catalyst surface contaminants and exposing highly reducible surface Ru oxides. Ru reduces nitrate selectively to ammonium, and no aqueous nitrite intermediate is observed during reactions. In contrast, reactions initiated with nitrite yield a mixture of two endproducts, with selectivity shifting from ammonium towards N 2 at increasing initial aqueous nitrite concentrations. Experimental observation and Density Functional Theory calculations

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Section: Catalytic Nitrite Reductionsupporting

confidence: 72%

Hydrogenation of aqueous nitrate and nitrite with ruthenium catalysts

Huo

Hoomissen

Liu

et al. 2017

Applied Catalysis B: Environmental

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“…This is in striking contrast with the conventional Pt-Ga catalysts, in which Ga is regarded as a promoter and Pt is the active element. 285,286 Other composite bimetallic catalysts, including Pd-Sn catalysts, 287,288 Pd-Zn catalysts, 230,289,290 Pt-Ni catalysts, 291 Pt-Fe, 292 and Rh-Cu catalysts, 293 have been reported for catalytic reactions, showing that the introduction of a second non-noble metal can significantly enhance the catalytic activity of monometallic catalysts.…”

Section: Bimetallic Catalystsmentioning

confidence: 99%

Recent advances in noble metal based composite nanocatalysts: colloidal synthesis, properties, and catalytic applications

et al. 2015

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This Review article provides a report on progress in the synthesis, properties and catalytic applications of noble metal based composite nanomaterials. We begin with a brief discussion on the categories of various composite materials. We then present some important colloidal synthetic approaches to the composite nanostructures; here, major attention has been paid to bimetallic nanoparticles. We also introduce some important physiochemical properties that are beneficial from composite nanomaterials. Finally, we highlight the catalytic applications of such composite nanoparticles and conclude with remarks on prospective future directions.

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“…The production of nitrogen fertilizers in large quantities, based on the artificial synthesis of ammonia [1], has allowed their intensive use in soils to improve the agricultural yield. Therefore, NO 3 − concentration has been increasing steadily in groundwater since 1950 [2]. In addition, the elimination of untreated municipal and industrial waste has increased the contamination of water by NO 3 − , generating some serious problems in the quality of water destined to human consumption [3,4].…”

Section: Introductionmentioning

confidence: 99%

“…The maximum contaminant level allowed by the US Environmental Protection Agency (EPA) is 10 ppm for N-NO 3 − (expressed in terms of nitrogen in NO 3 − ) in the water supply for the population [5]. For the World Health Organization (WHO) it is 50 ppm for NO 3 − and 1 ppm for NO 2 − [6]. The NO 3 − is harmful because it is reduced to NO 2 − in the mouth and intestines, favouring the development of methemoglobinemia, which causes a deficiency of oxygen in the blood that can be life-threatening, especially in children under six months of age ("blue baby syndrome").…”

Section: Introductionmentioning

confidence: 99%

Use of organo-montmorillonite for the nitrate retention in water: influence of alkyl length of loaded surfactants

et al. 2019

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The removal of NO 3 − from water was performed and compared among four organo-montmorillonites (OMt) with quaternary amine surfactants of different chain lengths [octadecyl trimethyl-(ODTMA), hexadecyl trimethyl-(HDTMA), tetradecyl trimethyl-(TDTMA) and dodecyl trimethyl-ammonium (DDTMA)] and loadings [100%, 200%, 400% of the Mt cation exchange capacity (CEC)]. The maximum adsorption of NO 3 − was attained by the long chain length surfactants (64 and 100 mg NO 3 − ions per gram of OMt, for HDTMA and ODTMA, respectively) with initial loading of 400% with respect to the CEC of Mt. The short chain length surfactants (DDTMA and TDTMA) did not show adsorption of NO 3 − except for TDTMA 400 sample. The NO 3 − adsorption produced a slight expansion of the interlayer thickness of the OMt samples loaded with long-chain surfactants that was assigned to the entrance of NO 3 − by a synergic effect with these surfactants. The decrease of the negative zeta potential, found for OMt samples relative to that of Mt sample, was attributed to the surfactant chain length rather than to the actual surfactant loaded amounts, which allowed attaining positive zeta potential values for the OMt loaded with long-chain surfactants. The NO 3 − adsorption on OMt samples caused a slight decrease in the positive zeta potential values, reflecting the external surface coating by NO 3 −. For long-chain molecules, this behaviour also indicated the formation of greater interactions such as ion pairs between the positive polar group of the surfactant and NO 3 − ions.

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Microkinetic modeling of the hydrogenation of nitrate in water on Pd–Sn/Al2O3 catalyst

Cited by 13 publications

References 36 publications

Hydrogenation of aqueous nitrate and nitrite with ruthenium catalysts

Hydrogenation of aqueous nitrate and nitrite with ruthenium catalysts

Recent advances in noble metal based composite nanocatalysts: colloidal synthesis, properties, and catalytic applications

Use of organo-montmorillonite for the nitrate retention in water: influence of alkyl length of loaded surfactants

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