Catalytic decomposition of nitrous oxide over catalysts prepared from Co/Mg-Mn/Al hydrotalcite-like compounds

Obalová, Lucie; Jirátová, Květa; Kovanda, František; Pacultová, Kateřina; Lacný, Zdeněk; Mikulová, Zuzana

doi:10.1016/j.apcatb.2005.04.002

Cited by 79 publications

(47 citation statements)

References 71 publications

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“…However, on comparing the CO 2 -TPD results and the catalytic activity measurement results, it can be seen that there is no clear relationship between the number of basic sites and the catalytic activities of these catalysts. Our observation is similar to the findings of Obalová et al (33,34). Therefore, we conclude that the number of basic sites on the catalyst is not a key parameter in determining the catalytic decomposition of N 2 O.…”

Section: Catalytic Activity Measurementssupporting

confidence: 92%

Promotion Effects and Mechanism of Alkali Metals and Alkaline Earth Metals on Cobalt−Cerium Composite Oxide Catalysts for N₂O Decomposition

Xue

Liu

et al. 2009

Environ. Sci. Technol.

124

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A series of alkali metal-and alkaline earth metal-doped cobalt-cerium composite oxide catalysts were prepared by the citrate method and tested for the decomposition of N 2 O. Strong promotion effects of alkali and alkaline earth metals on the activity of the catalyst were obtained in the order Li < Na < K < Rb < Cs and Mg < Ca < Sr, Ba. The promotion effects of alkaline earth metals were much weaker than the effects of alkali metals. To investigate the origin of the promotion effect, X-ray diffraction, Brunauer-Emmett-Teller surface area measurement, X-ray photoelectron spectroscopy, temperature-programmed desorption, and hydrogen temperatureprogrammed reduction methods were used to characterize the alkali metal-doped catalyst. The analytical results indicated that alkali metals improved the redox ability of active site Co 2+ by acting as electronic promoters. Catalytic decomposition of N 2 O proceeds through an oxidation-reduction mechanism with participation of electrons from Co 2+ , thus the increase in the redox ability of Co 2+ should lead to an increase in the activity of the catalyst.

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Section: Catalytic Activity Measurementssupporting

confidence: 92%

Promotion Effects and Mechanism of Alkali Metals and Alkaline Earth Metals on Cobalt−Cerium Composite Oxide Catalysts for N₂O Decomposition

Xue

Liu

et al. 2009

Environ. Sci. Technol.

124

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“…The best results were obtained for the Co-Al sample with the Co/Al ratio of 3. Calcined Co-Mn-Al hydrotalcites were studied by Obalova et al [18][19][20], who proposed the optimal method for synthesis of effective catalysts and reported high activity of these oxide systems in the presence of O 2 and NO x . Chang et al [21] reported high activity of calcined Co-Al hydrotalcites containing additionally rhodium, palladium, or cerium in the process of N 2 O decomposition and reduction by carbon monoxide.…”

Section: Introductionmentioning

confidence: 99%

An influence of thermal treatment conditions of hydrotalcite-like materials on their catalytic activity in the process of N2O decomposition

Chmielarz

Rutkowska

Kuśtrowski

et al. 2011

J Therm Anal Calorim

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Hydrotalcite-like materials containing apart from magnesium and aluminum also copper, cobalt, nickel, and iron were prepared by a co-precipitation method. Thermal transformations of hydrotalcite-like materials were studied by thermal analysis methods as well as XRD, UV-vis-DRS, and XPS measurements of the samples calcined at various temperatures (600, 700, and 800°C). Calcined hydrotalcites, especially those containing cobalt and copper, were found to be active and selective catalysts of N 2 O decomposition. It was shown that an increase in the calcination temperature significantly activated the Co-containing catalysts. Promotion of the samples with potassium resulted in activation of the hydrotalcite-based catalysts.

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“…As a catalyst support, CHT can be used for nitrous oxide decomposition [28], MIBK synthesis [29], etc.…”

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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Catalytic decomposition of nitrous oxide over catalysts prepared from Co/Mg-Mn/Al hydrotalcite-like compounds

Cited by 79 publications

References 71 publications

Promotion Effects and Mechanism of Alkali Metals and Alkaline Earth Metals on Cobalt−Cerium Composite Oxide Catalysts for N₂O Decomposition

Promotion Effects and Mechanism of Alkali Metals and Alkaline Earth Metals on Cobalt−Cerium Composite Oxide Catalysts for N₂O Decomposition

An influence of thermal treatment conditions of hydrotalcite-like materials on their catalytic activity in the process of N2O decomposition

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

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Catalytic decomposition of nitrous oxide over catalysts prepared from Co/Mg-Mn/Al hydrotalcite-like compounds

Cited by 79 publications

References 71 publications

Promotion Effects and Mechanism of Alkali Metals and Alkaline Earth Metals on Cobalt−Cerium Composite Oxide Catalysts for N2O Decomposition

Promotion Effects and Mechanism of Alkali Metals and Alkaline Earth Metals on Cobalt−Cerium Composite Oxide Catalysts for N2O Decomposition

An influence of thermal treatment conditions of hydrotalcite-like materials on their catalytic activity in the process of N2O decomposition

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

Contact Info

Product

Resources

About

Promotion Effects and Mechanism of Alkali Metals and Alkaline Earth Metals on Cobalt−Cerium Composite Oxide Catalysts for N₂O Decomposition

Promotion Effects and Mechanism of Alkali Metals and Alkaline Earth Metals on Cobalt−Cerium Composite Oxide Catalysts for N₂O Decomposition