Decomposition kinetics of ammonia in gaseous stream by a nanoscale copper-cerium bimetallic catalyst

Dong, Cheng–Di

doi:10.1016/j.jhazmat.2007.04.044

Cited by 33 publications

(23 citation statements)

References 35 publications

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“…Zhou and Cheng demonstrated that the adsorption and desorption of N x H y intermediates play important roles in NH 3 catalytic electrolysis and hydrogen evolution [38]. On the other hand, the ammonia oxidation also might proceed via a way other than the LangmuireHinshelwood (LeH) mechanism proposed by Hung [39]. As such, the reaction mechanism warrants further investigation to elucidate the performance of the PtPdRh alloy catalyst at the scan rates of 5 and 10 mV/s.…”

Section: Resultsmentioning

confidence: 99%

Electrochemical properties of PtPdRh alloy catalysts for ammonia electrocatalytic oxidation

Dong

2012

International Journal of Hydrogen Energy

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Section: Resultsmentioning

confidence: 99%

Electrochemical properties of PtPdRh alloy catalysts for ammonia electrocatalytic oxidation

Dong

2012

International Journal of Hydrogen Energy

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“…Highly pure He was used as a carrier gas at a flow rate ranging from 8 to 13 L/min and was controlled using a mass flow meter (830 Series Side-Trak TM , Sierra, Monterey, CA, USA). This approach resembled that of Hung (2008b), who conducted experiments on the catalytic oxidation of NH 3 . A reaction tube with a length of 300 mm and an inner diameter of 28 mm was placed inside a split tube furnace with the tube that contained the catalyst.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…Additionally, a recent study described the efficient catalytic oxidation of NH 3 in a gaseous stream using a nanoscale copper-cerium bimetallic catalyst in a temperature range of 423 to 673 K at a GHSV of 92,000/hr. The bimetallic nanoscale structure had the greatest NH 3 reduction activity, and the N 2 selectivity exhibited a synergistic effect (Hung, 2008b). Brüggemann and co-workers (2009) stated that a density functional theory of the effect of H-ZSM5 catalysts and their activity and selectivity in oxidizing NH 3 .…”

Section: Introductionmentioning

confidence: 99%

Removal of Gaseous Ammonia in Pt-Rh Binary Catalytic Oxidation

Dong

Lai

Lin

2012

Aerosol Air Qual. Res.

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In this study, the oxidation of ammonia (NH 3 ) to form nitrogen was investigated by selective catalytic oxidation (SCO) over a Pt-Rh binary catalyst fabricated by the incipient wetness impregnation process in a tubular fixed-bed flow quartz reactor (TFBR). The catalysts were analysed by three-dimensional excitation-emission fluorescent matrix (EEFM) spectroscopy, UV-Vis absorption, dynamic light-scattering (DLS), zeta potential measurements, and linear sweep voltammograms (LSV). At optimum conditions, namely, a temperature of 673 K and an oxygen content of 4%, nearly 100% of the NH 3 was removed by catalytic oxidation over the Pt-Rh binary catalyst. The main product of the NH 3 -SCO process was N 2 . Additionally, for the freshly prepared Pt-Rh binary catalyst, three peaks (at 235/295 nm, 245/315 nm, and 240/365 nm) were observed via EEFM; however, the peak with the highest emission wavelength disappeared over time as Pt-Rh binary catalyst was exhausted by NH 3 . These results show that EEFM spectroscopy, which enhances intrinsic emission Pt clusters in the Pt-Rh binary catalyst, is an effective method for characterizing this catalyst in catalytic treatment systems. The UV-Vis absorption spectra revealed that the bands associated with such octahedral platinum (IV) species were observed at about 350 nm. Moreover, the LSV reversible redox ability may explain the significant activity of the catalysts.

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“…An inert material formed from (hydrophilic and inert) γ-Al 2 O 3 spheres was used to increase the interfacial area between the solid and the gas phase to increase the mass transfer of NH 3 from gaseous streams. This approach resembled that of Hung (2008a), who conducted experiments on the catalytic oxidation of NH 3 . A reaction tube with a length of 300 mm and an inner diameter of 28-mm was placed inside a split tube furnace.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…Moreover, Wang et al (1999), who developed Ni-based catalysts for oxidizing fuel gas generated by gasifying biomass, found that fresh Ni-based catalysts were more active at lower temperatures in decomposing of NH 3 , and the partial pressure of H 2 in the flue gas is a critical factor that governed NH 3 oxidation. One of the recent works has summarized that the catalytic oxidation of NH 3 in gaseous stream by a nanoscale Cu/Ce bimetallic catalyst in the temperature range 423-673 K at GHSV=92,000 1/hr (Hung, 2008a). There is a synergistic effect of the bimetallic nanoscale structure, which is the material with the highest NH 3 reduction activity and the highest N 2 selectivity.…”

Section: Introductionmentioning

confidence: 99%

Honeycomb Cordierite-Carriers Pt-Pd-Rh Ternary Composite for Ammonia Removal

Dong

2010

Aerosol Air Qual. Res.

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This work considers the development of ammonia (NH 3 ) by selective catalytic oxidation (SCO) over a honeycomb Pt-Pd-Rh ternary composite cordierite catalyst in a tubular fixed-bed flow quartz reactor (TFBR) at temperatures between 423 and 623 K. A honeycomb Pt-Pd-Rh ternary composite cordierite catalyst was prepared by incipient wetness impregnation with aqueous solutions of H 2 PtCl 6 , Pd(NO 3 ) 3 and Rh(NO 3 ) 3 that were coated on cordierite cellular ceramic materials. The catalysts were characterized using OM, TGA-DTA, SEM/EDX and TEM. Based on the experimental results show that around 99.5% NH 3 removal was achieved during catalytic oxidation over the honeycomb Pt-Pd-Rh ternary composite cordierite catalyst at 623 K with an oxygen content of 4%. N 2 was the main product in the NH 3 -SCO process over the honeycomb Pt-Pd-Rh ternary composite cordierite catalyst. Moreover, the present study also shows that contaminants crystal aggregation phases and washcoat loss may be responsible for the deactivation of the catalysts. These results also verify that the high initial concentration of the influent NH 3 decreases the efficiency of removal of ammonia.

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Decomposition kinetics of ammonia in gaseous stream by a nanoscale copper-cerium bimetallic catalyst

Cited by 33 publications

References 35 publications

Electrochemical properties of PtPdRh alloy catalysts for ammonia electrocatalytic oxidation

Electrochemical properties of PtPdRh alloy catalysts for ammonia electrocatalytic oxidation

Removal of Gaseous Ammonia in Pt-Rh Binary Catalytic Oxidation

Honeycomb Cordierite-Carriers Pt-Pd-Rh Ternary Composite for Ammonia Removal

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