Selective hydrogenation of nitrate in water over Cu–Pd/mordenite

Nakamura, Kyosuke; Yoshida, Yasuyuki; Mikami, Ikkou; Okuhara, Toshio

doi:10.1016/j.apcatb.2005.12.012

Cited by 78 publications

(57 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, they show high activity in the reduction of nitrites [3][4][5][12][13][14]. Among the studied bimetallic systems, palladium systems promoted with Cu, Sn, Ag or Fe supported on different kinds of oxide carriers [14][15][16][17][18][19][20], polymers [21,22], zeolites [23], active carbons [24][25][26], resin [27][28][29], showed the best catalytic characteristics. The mechanism of these systems has not been explained unequivocally yet.…”

Section: Introductionmentioning

confidence: 99%

The effect of support porosity on the selectivity of Pd–In/support catalysts in nitrate reduction

Krawczyk

Karski

Witońska

2011

Reac Kinet Mech Cat

View full text Add to dashboard Cite

The influence of support porosity on the selectivity of home-made 5%Pd-2%In/support (support = SiO 2 , Al 2 O 3 , TiO 2 ) catalysts in nitrate reduction was studied. The main final products of the reaction were N 2 and NH 4? . Together with the decrease in pore diameter, an increase in ammonia concentration in the reaction mixture was observed. It is probably caused by slow diffusion of OH -ions from narrow pores to the solution.

show abstract

Section: Introductionmentioning

confidence: 99%

The effect of support porosity on the selectivity of Pd–In/support catalysts in nitrate reduction

Krawczyk

Karski

Witońska

2011

Reac Kinet Mech Cat

View full text Add to dashboard Cite

show abstract

“…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

View full text Add to dashboard Cite

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:

show abstract

“…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

View full text Add to dashboard Cite

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.

show abstract

Selective hydrogenation of nitrate in water over Cu–Pd/mordenite

Cited by 78 publications

References 31 publications

The effect of support porosity on the selectivity of Pd–In/support catalysts in nitrate reduction

The effect of support porosity on the selectivity of Pd–In/support catalysts in nitrate reduction

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

Contact Info

Product

Resources

About