Hydrogenations of nitrate and nitrite in water over Pt–promoted Ni catalysts

Mikami, Ikkou; Kitayama, Reo; Okuhara, Toshio

doi:10.1016/j.apcata.2005.08.038

Cited by 28 publications

(27 citation statements)

References 30 publications

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“…Most of the work in the area of catalytic nitrate reduction has been done using Pd-Cu bimetallic catalysts; also Pd-Sn and Pt-Cu on different supports, mainly alumina, have been considered [1-4, 6-8, 17-19]. A few investigations have been reported for other metallic pairs [15,20,22,[28][29][30][31]. Therefore, we decided to study systematically the nitrate reduction in the presence of a larger set of bimetallic catalysts (Pd-Cu, PtCu, Rh-Cu, Ru-Cu, Pd-Ir, Pd-Sn, Pd-Fe, Pd-Ni, Pd-Zn, Ir-Cu, Rh-Sn, Pt-Sn and Pt-Fe) supported on activated carbon, with 1 wt% of each metal, in order to select the most promising systems.…”

Section: Bimetallic Catalystsmentioning

confidence: 99%

Activated Carbon Supported Metal Catalysts for Nitrate and Nitrite Reduction in Water

2008

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Ten monometallic and 13 bimetallic catalysts supported on activated carbon were assessed, the former in the reduction of nitrate or nitrite and the latter in the nitrate reduction. Under the conditions used, nitrite was shown to be reduced by monometallic catalysts. With exception of Ru, only some of the bimetallic catalysts were able to reduce nitrate. Rh-Cu shows the highest conversion, but Pd-Cu is the most promising catalyst if selectivity into nitrogen is also considered.

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Section: Bimetallic Catalystsmentioning

confidence: 99%

Activated Carbon Supported Metal Catalysts for Nitrate and Nitrite Reduction in Water

2008

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“…Palladium was found to be the most active and selective metal for the reduction of nitrate, but the reduction of nitrate required a second metal as a co-catalyst [9]. Pd-Cu, Pd-Sn and Pd-In coated on support materials such as Al 2 O 3 or hydrotalcite have been shown to reduce nitrate when added to a solution along with hydrogen as an electron donor [8][9][10][11][12][13][14][15]. The catalytic reduction results in the production of nitrogen (N 2 ) gas and NO 2 -as intermediates [15].…”

Section: Introductionmentioning

confidence: 99%

“…However, physico-chemical processes, such as ionexchange, reverse osmosis and electrodialysis, produce concentrated brine that must be treated or disposed of, and biological denitrification of drinking water is limited due to concerns with pathogens, turbidity, and chlorine demand in the treated water. Catalytic reduction of nitrate, including chemical catalytic methods and electrochemical catalytic methods, is emerging as the most promising and flexible technique to solve this problem [8][9][10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Efficient Nitrate Reduction in a Fluidized Electrochemical Reactor Promoted by Pd–Sn/AC Particles

Lan

Liu

et al. 2015

Catal Lett

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Pd-Sn modified activated carbon (Pd-Sn/AC) was prepared by impregnation of Pd and Sn salts onto AC followed by heat treatment. Based on scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analysis, Pd-Sn alloy was highly dispersed on the surface of AC with a atomic ratio of about 4.21. A double electrolysis cell was established and separated via a proton-exchange membrane. In the cathodic cell compartment, the as-prepared Pd-Sn/AC was used as particle electrodes where electrolytic reduction of nitrate was performed. A batch mode study showed that at an applied current of 30 mA with 7.5 g/L catalyst, over 90 % of the nitrate could be reduced in 80 min when the nitrate initial concentration was 24.6 mg/L. The electro-catalytic process of nitrate reduction could be satisfactorily described with a first-order kinetics model. With increasing applied current, the nitrate removal rate increased; whereas, the NH 4 ? concentration increased as well. The inhibition effect of coexisting anions and cations on nitrate reduction followed this order:

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“…Nitrate can be reduced to nitrogen using H 2 as the reductant over bimetallic catalysts. The catalysts combining a noble metal, such as Pd or Pt, and another metal, usually Cu, Sn, and Ni supported on γ -Al 2 O 3 , HZSM, etc., have been studied for this reaction [10][11][12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

“…There is a wide range of technologies to remove nitrate from water including physical-chemical [4][5][6], biological [7][8][9], and catalytic processes [10][11][12][13][14][15][16][17][18]. Conventional physical-chemical techniques such as ion-exchange, reverse osmosis, and sorption processes cannot convert nitrate into harmless compounds but only remove nitrate from water to brine which afterward needs treatment.…”

Section: Introductionmentioning

confidence: 99%

Role of the Mg/Al atomic ratio in hydrotalcite-supported Pd/Sn catalysts for nitrate adsorption and hydrogenation reduction

Wan¹,

Liu²,

Zhao³

et al. 2009

Journal of Colloid and Interface Science

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Hydrotalcite-supported Pd/Sn catalysts with different Mg/Al atomic ratios (2, 3, 4, and 5) for nitrate adsorption and hydrogenation reduction were successfully synthesized by a coprecipitation method. The results showed that different atomic ratios of Mg/Al resulted in different interlayer spacings and zetapotentials of the catalysts, which thus influenced its adsorption capacity. With the increase of Mg/Al atomic ratio, the interlayer spacing rose and zeta-potential decreased. The adsorption properties of the catalysts were mainly affected by interlayer spacing when Mg/Al atomic ratios increased from 2 to 4. However, when Mg/Al atomic ratios further increased from 4 to 5, there was a negative impact on the adsorption properties of zeta-potential. Also, the adsorption capacity of the catalysts for nitrate followed the order: Mg/Al = 2 < Mg/Al = 3 < Mg/Al = 5 < Mg/Al = 4. In the catalytic reduction process, the adsorbed nitrates were further reduced to nitrites that remained in the same position in catalysts, but some of superabundant nitrites were released into water as primary and unstable products. The concentration of released nitrites was in the reverse order of the adsorption capacity. The catalytic selectivity and activity of the catalysts for nitrate reduction had the same sequence as its adsorption capacity.

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Hydrogenations of nitrate and nitrite in water over Pt–promoted Ni catalysts

Cited by 28 publications

References 30 publications

Activated Carbon Supported Metal Catalysts for Nitrate and Nitrite Reduction in Water

Activated Carbon Supported Metal Catalysts for Nitrate and Nitrite Reduction in Water

Efficient Nitrate Reduction in a Fluidized Electrochemical Reactor Promoted by Pd–Sn/AC Particles

Role of the Mg/Al atomic ratio in hydrotalcite-supported Pd/Sn catalysts for nitrate adsorption and hydrogenation reduction

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