Selective catalytic reduction of NO by C3H8 over CoOx/Al2O3: An investigation of structure–activity relationships

This work is aimed at solving the problem on sorption purification of waste gases from sulfur dioxide on the wastes of phosphoric industry, i.e. thermophosphorus slags (TPhS). The solution of this problem is implemented by the new technical result, which is caused in increasing the depth of treatment by sulfur dioxide. Essential features of the claimed technical solution are the sorption purification of sulfur dioxide from waste gases on sorbent, containing layer of the granular TPhS. The experimental results showed that the highest activity of the sorbent, calcined at 500°C, is manifested at a temperature of sorption of 200 °C. With further increase of the process temperature, the degree of sorption does not change and duration of work of the sorbent is reduced.

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“…The temperature in the reactor is regulated by a potentiometer 13 . The installation is equipped with samplers 8,14 .…”

Section: Methodsmentioning

confidence: 99%

Adsorption-catalytic Purification of Gas Mixtures from Sulphur Dioxide by Sorbent of Phosphoric Production Wastes

Kaldybayev¹,

Shakirov²,

Adilbekovna³

et al. 2015

Biosci., Biotech. Res. Asia

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“…Na crystallite (2h of 29.420) is obtained in Rh-Na/Al 2 O 3 catalysts (Fig. 2b) [13,14], which indicated that the catalysts containing metal aluminates had higher activity for NO reduction than metal oxides at low temperatures. As a result, adding Na to modify the Rh/Al 2 O 3 catalysts can significantly improve the efficiency of NO removal in the simulated flue gas which contains 6% O 2 .…”

Section: Catalyst Characterizationmentioning

confidence: 99%

Effects of Na, Cu, Ni and Co Modifications on the Activity and Characteristics of Rh/Al2O3 Catalysts for NO Reduction

2008

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This study used different metals to modify Rh/ Al 2 O 3 catalysts for NO reduction in a simulated waste incineration flue gas containing 6% O 2 . The characteristics of the modified catalysts were analyzed using BET, TEM and XRD. The results of the experiment reveal that Na addition can significantly affect the properties of Rh/Al 2 O 3 catalysts on the BET surface area and Rh metal dispersion. Furthermore, Na addition was found to significantly enhance the NO conversion of Rh/Al 2 O 3 at 250-350°C. On the contrary, Cu, Ni, and Co addition was found to have slight suppression effects.

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“…However, highly dispersed CoAl 2 O 4 crystallites on alumina have also been proposed to be the active centers of NO reduction by investigating the effects of catalyst preparation method and calcination temperatures on the properties of Co/Al 2 O 3 [15]. Likewise, a recent report by He et al [14], in which the structure of CoO x / Al 2 O 3 catalysts and their activity for C 3 H 6 -SCR were studied, proposed that tiny CoAl 2 O 4 crystallites highly dispersed on alumina were responsible for the efficient catalytic reduction of NO, whereas Co 3 O 4 crystallites only catalyzed the combustion of C 3 H 8 . These results were different from that reported by Yan and Maunula et al [8,13].…”

Section: Introductionmentioning

confidence: 95%

“…Generally, the catalytic activity of cobalt supported alumina catalysts depends on the type of support, preparation method, metal loading and calcination temperatures [8,14,15], major challenge to understand the activity of Co/Al 2 O 3 catalysts lies in the heterogeneous distribution of cobalt species. Indeed, the state of Co species is a key issue which closely associates with the activity and mechanism of Co/Al 2 O 3 .…”

Section: Introductionmentioning

confidence: 99%

The Nature of Active Sites of Co/Al2O3 for the Selective Catalytic Reduction of NO with C2H4

2009

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The effects of Co loading and calcination temperatures on the catalytic activity of Co/Al 2 O 3 for selective catalytic reduction (SCR) of NO with ethylene in excess oxygen were investigated. Co/Al 2 O 3 showed high and low activities when calcined at high (800°C) and low (350°C) temperatures, respectively. The formation and dispersion of cobalt species for catalysts calcined at 350 and 800°C as well as for Al 2 O 3 were studied by XRD, UV-vis and FTIR spectra. Combined with DRIFTS results of ad-species and reaction experiments, it allowed us to correlate the catalytic activity with active sites of Co/Al 2 O 3 , and the catalytic functions of active cobalt species and support were clarified. Co 3 O 4 species contributed to the oxidation of NO to various nitrates and of C 2 H 4 to reactive formate species, even in the absence of O 2 , whereas the side reaction of ethylene combustion occurred simultaneously when excess oxygen was present. Tetrahedral Co 2? ions in CoAl 2 O 4 , which acted as the active sites, were responsible for the reaction between formate and nitrate species to form organic nitro compound.

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Selective catalytic reduction of NO by C3H8 over CoOx/Al2O3: An investigation of structure–activity relationships

Cited by 41 publications

References 43 publications

Adsorption-catalytic Purification of Gas Mixtures from Sulphur Dioxide by Sorbent of Phosphoric Production Wastes

Adsorption-catalytic Purification of Gas Mixtures from Sulphur Dioxide by Sorbent of Phosphoric Production Wastes

Effects of Na, Cu, Ni and Co Modifications on the Activity and Characteristics of Rh/Al2O3 Catalysts for NO Reduction

The Nature of Active Sites of Co/Al2O3 for the Selective Catalytic Reduction of NO with C2H4

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