The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
M. Kantcheva - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Niobium-zirconium Mixed Oxide as a Novel Catalyst for Selective Catalytic Reduction of NO_ x
Catalysis Letters, 2009Co-Authors: I. Cayirtepe, A. Naydenov, G. Ivanov, M. KantchevaAbstract:The performance of mixed niobium-zirconium oxide in the SCR of NO_ x with propene in excess oxygen has been studied. The mixed oxide is prepared by impregnation of hydrated zirconia with acidic solution (pH 0.5) of peroxoniobium(V) complex, [Nb_2(O_2)_3]^4+, ensuring ZrO_2:Nb_2O_5 mole ratio of 6:1. The calcined sample (denoted as 25NbZ-P) has the structure of Zr_6Nb_2O_17. According to the catalytic test, the conversion of NO_ x over the 25NbZ-P Catalyst passes through a maximum at 220 °C. Based on the in situ FT-IR results, a reaction mechanism is proposed with nitroacetone and NCO species as the key reaction intermediates. The results of the investigation show that the catalytic properties of the Zr_6Nb_2O_17 solid solution could be of interest regarding the development of Low-Temperature Catalyst for the SCR of NO_ x with hydrocarbons.
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Characterization of Niobium-zirconium Mixed Oxide as a Novel Catalyst for Selective Catalytic Reduction of NOx
Catalysis Letters, 2009Co-Authors: I. Cayirtepe, A. Naydenov, G. Ivanov, M. KantchevaAbstract:The performance of mixed niobium-zirconium oxide in the SCR of NOx with propene in excess oxygen has been studied. The mixed oxide is prepared by impregnation of hydrated zirconia with acidic solution (pH 0.5) of peroxoniobium(V) complex, [Nb2(O2)3]4+, ensuring ZrO2:Nb2O5 mole ratio of 6:1. The calcined sample (denoted as 25NbZ-P) has the structure of Zr6Nb2O17. According to the catalytic test, the conversion of NOx over the 25NbZ-P Catalyst passes through a maximum at 220 °C. Based on the in situ FT-IR results, a reaction mechanism is proposed with nitroacetone and NCO species as the key reaction intermediates. The results of the investigation show that the catalytic properties of the Zr6Nb2O17 solid solution could be of interest regarding the development of Low-Temperature Catalyst for the SCR of NOx with hydrocarbons.
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Characterization of Niobium-zirconium Mixed Oxide as a Novel Catalyst for Selective Catalytic Reduction of NO x
Catalysis Letters, 2009Co-Authors: I. Cayirtepe, A. Naydenov, G. Ivanov, M. KantchevaAbstract:The performance of mixed niobium-zirconium oxide in the SCR of NO x with propene in excess oxygen has been studied. The mixed oxide is prepared by impregnation of hydrated zirconia with acidic solution (pH 0.5) of peroxoniobium(V) complex, [Nb2(O2)3] 4+, ensuring ZrO2:Nb2O5 mole ratio of 6:1. The calcined sample (denoted as 25NbZ-P) has the structure of Zr 6Nb2O17. According to the catalytic test, the conversion of NO x over the 25NbZ-P Catalyst passes through a maximum at 220 °C. Based on the in situ FT-IR results, a reaction mechanism is proposed with nitroacetone and NCO species as the key reaction intermediates. The results of the investigation show that the catalytic properties of the Zr6Nb2O17 solid solution could be of interest regarding the development of Low-Temperature Catalyst for the SCR of NO x with hydrocarbons. © 2009 Springer Science+Business Media, LLC
Shoou-jinn Chang - One of the best experts on this subject based on the ideXlab platform.
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Two-dimensional ZnO nanowalls for gas sensor and photoelectrochemical applications
Electronic Materials Letters, 2014Co-Authors: Sheng-po Chang, Shoou-jinn ChangAbstract:Zinc oxide (ZnO) nanowalls were vertically grown on a glass substrate through a fast, Low-Temperature, Catalyst-free process in a tube furnace. The morphology and microstructure of ZnO nanowalls were characterized by field-emission scanning electron microscopy, x-ray diffraction analysis, transmission electron microscopy, and photoluminescence measurements. The ZnO nanowall films showed strong UV emission and preferential c -axis orientation, with a hexagonal structure. Potential applications of the ZnO nanowalls were further investigated through experiments. The sensitivity of ZnO-based carbon monoxide gas sensors increased with increasing Temperature and reached a maximum value at 300°C. In photoelectrochemical experiments, direct photoelectrolysis of water to generate hydrogen was performed using the ZnO nanowalls as the working photoelectrode. For an external bias of 1.2 V, the photocurrent densities reached 0.037 A/cm^2 under Xe lamp illumination.
I. Cayirtepe - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Niobium-zirconium Mixed Oxide as a Novel Catalyst for Selective Catalytic Reduction of NO_ x
Catalysis Letters, 2009Co-Authors: I. Cayirtepe, A. Naydenov, G. Ivanov, M. KantchevaAbstract:The performance of mixed niobium-zirconium oxide in the SCR of NO_ x with propene in excess oxygen has been studied. The mixed oxide is prepared by impregnation of hydrated zirconia with acidic solution (pH 0.5) of peroxoniobium(V) complex, [Nb_2(O_2)_3]^4+, ensuring ZrO_2:Nb_2O_5 mole ratio of 6:1. The calcined sample (denoted as 25NbZ-P) has the structure of Zr_6Nb_2O_17. According to the catalytic test, the conversion of NO_ x over the 25NbZ-P Catalyst passes through a maximum at 220 °C. Based on the in situ FT-IR results, a reaction mechanism is proposed with nitroacetone and NCO species as the key reaction intermediates. The results of the investigation show that the catalytic properties of the Zr_6Nb_2O_17 solid solution could be of interest regarding the development of Low-Temperature Catalyst for the SCR of NO_ x with hydrocarbons.
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Characterization of Niobium-zirconium Mixed Oxide as a Novel Catalyst for Selective Catalytic Reduction of NOx
Catalysis Letters, 2009Co-Authors: I. Cayirtepe, A. Naydenov, G. Ivanov, M. KantchevaAbstract:The performance of mixed niobium-zirconium oxide in the SCR of NOx with propene in excess oxygen has been studied. The mixed oxide is prepared by impregnation of hydrated zirconia with acidic solution (pH 0.5) of peroxoniobium(V) complex, [Nb2(O2)3]4+, ensuring ZrO2:Nb2O5 mole ratio of 6:1. The calcined sample (denoted as 25NbZ-P) has the structure of Zr6Nb2O17. According to the catalytic test, the conversion of NOx over the 25NbZ-P Catalyst passes through a maximum at 220 °C. Based on the in situ FT-IR results, a reaction mechanism is proposed with nitroacetone and NCO species as the key reaction intermediates. The results of the investigation show that the catalytic properties of the Zr6Nb2O17 solid solution could be of interest regarding the development of Low-Temperature Catalyst for the SCR of NOx with hydrocarbons.
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Characterization of Niobium-zirconium Mixed Oxide as a Novel Catalyst for Selective Catalytic Reduction of NO x
Catalysis Letters, 2009Co-Authors: I. Cayirtepe, A. Naydenov, G. Ivanov, M. KantchevaAbstract:The performance of mixed niobium-zirconium oxide in the SCR of NO x with propene in excess oxygen has been studied. The mixed oxide is prepared by impregnation of hydrated zirconia with acidic solution (pH 0.5) of peroxoniobium(V) complex, [Nb2(O2)3] 4+, ensuring ZrO2:Nb2O5 mole ratio of 6:1. The calcined sample (denoted as 25NbZ-P) has the structure of Zr 6Nb2O17. According to the catalytic test, the conversion of NO x over the 25NbZ-P Catalyst passes through a maximum at 220 °C. Based on the in situ FT-IR results, a reaction mechanism is proposed with nitroacetone and NCO species as the key reaction intermediates. The results of the investigation show that the catalytic properties of the Zr6Nb2O17 solid solution could be of interest regarding the development of Low-Temperature Catalyst for the SCR of NO x with hydrocarbons. © 2009 Springer Science+Business Media, LLC
Dan Luss - One of the best experts on this subject based on the ideXlab platform.
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Lean NO_x Reduction with H_2 and CO in Dual-Layer LNT–SCR Monolithic Catalysts: Impact of Ceria Loading
Topics in Catalysis, 2013Co-Authors: Yang Zheng, Michael P. Harold, Dan LussAbstract:A series of monolithic Catalysts consisting of a layer of selective catalytic reduction (SCR) Catalyst deposited on top of lean NO_x trap (LNT) Catalyst were synthesized for lean reduction of NO_x (NO&NO_2) with H_2 and CO. The LNT Catalyst exhibited a rather Low NO_x conversion beLow 250 °C due to CO inhibition. The top SCR layer comprising Cu/ZSM5 significantly increased the NO_x conversion at Low Temperature by its reaction with NH_3 formed during the regeneration phase. The addition of CeO_2 to the LNT layer promoted the water gas shift reaction (CO + H_2O ↔ H_2 + CO_2). The WGS reaction mitigated the CO inhibition and the generated H_2 enhanced the Low-Temperature Catalyst regeneration. The ceria addition decreased the performance at high Temperatures due to increased oxidation of NH_3. The ceria loading was optimized by applying a non-uniform axial profile. A dual-layer Catalyst with an increasing ceria loading axial profile improved the performance over a wide (Low and high) Temperature range.
Sheng-po Chang - One of the best experts on this subject based on the ideXlab platform.
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Two-dimensional ZnO nanowalls for gas sensor and photoelectrochemical applications
Electronic Materials Letters, 2014Co-Authors: Sheng-po Chang, Shoou-jinn ChangAbstract:Zinc oxide (ZnO) nanowalls were vertically grown on a glass substrate through a fast, Low-Temperature, Catalyst-free process in a tube furnace. The morphology and microstructure of ZnO nanowalls were characterized by field-emission scanning electron microscopy, x-ray diffraction analysis, transmission electron microscopy, and photoluminescence measurements. The ZnO nanowall films showed strong UV emission and preferential c -axis orientation, with a hexagonal structure. Potential applications of the ZnO nanowalls were further investigated through experiments. The sensitivity of ZnO-based carbon monoxide gas sensors increased with increasing Temperature and reached a maximum value at 300°C. In photoelectrochemical experiments, direct photoelectrolysis of water to generate hydrogen was performed using the ZnO nanowalls as the working photoelectrode. For an external bias of 1.2 V, the photocurrent densities reached 0.037 A/cm^2 under Xe lamp illumination.
