K-Modified Co–Mn–Al Mixed Oxide—Effect of Calcination Temperature on N2O Conversion in the Presence of H2O and NOx

Karásková, Kateřina; Pacultová, Kateřina; Jirátová, Květa; Fridrichová, Dagmar; Koštejn, Martin; Obalová, Lucie

doi:10.3390/catal10101134

Cited by 12 publications

(6 citation statements)

References 69 publications

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“…The binding energy of Co 2p and the shape of the spectra correspond to Co 3 O 4 , which is consistent with the results published in [52]. Based on our recent XPS study using appropriate standards [53][54][55] and work [52,56], the lower BE component (around 780 eV) was assigned to octahedral Co 3+ and the higher BE components (around 781.5 and around 783.5 eV) to tetrahedral Co 2+ . The positions of the second and third fitting peaks from the first fitting peak were set to +1.5 and +3.6 eV, respectively.…”

Section: Surface Compositionsupporting

confidence: 90%

Effect of Zinc on the Structure and Activity of the Cobalt Oxide Catalysts for NO Decomposition

et al. 2022

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Co4−iZniMnAlOx mixed oxides (i = 0, 0.5 and 1) were prepared by coprecipitation, subsequently modified with potassium (2 or 4 wt.% K), and investigated for direct catalytic NO decomposition, one of the most attractive and challenging NOx abatement processes. The catalysts were characterised by atomic absorption spectroscopy, powder X-ray diffraction, Raman and infrared spectroscopy, temperature-programmed reduction by hydrogen, the temperature-programmed desorption of CO2 and NO, X-ray photoelectron spectroscopy, scanning electron microscopy, the work function, and N2 physisorption. The partial substitution of cobalt increased the specific surface area, decreased the pore sizes, influenced the surface composition, and obtained acid-base properties as a result of the higher availability of medium and strong basic sites. No visible changes in the morphology, crystallite size, and work function were observed upon the cobalt substitution. The conversion of NO increased after the Co substitution, however, the increase in the amount of zinc did not affect the catalytic activity, whereas a higher amount of potassium caused a decrease in the NO conversion. The results obtained, which were predominantly the acid-base characteristics of the catalyst, are in direct correlation with the proposed NO decomposition reaction mechanisms with NOx− as the main reaction intermediates.

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Section: Surface Compositionsupporting

confidence: 90%

Effect of Zinc on the Structure and Activity of the Cobalt Oxide Catalysts for NO Decomposition

et al. 2022

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“…Activity levels for these catalysts can be altered by changing the Mg/Al ratio and calcination temperature [177]. The highest activity levels were achieved with a combination of an Mg/Al at a molar ratio of approximately 3 and a calcination temperature of 500 • C [178,179]. In a study carried out by Zhang et al, (2008), biodiesel conversion of 99% was achieved for acidic cottonseed oil (FFA 9.5 wt%).…”

Section: Heterogeneous Base Catalysts For Biodiesel Productionmentioning

confidence: 99%

A Short Review on Catalyst, Feedstock, Modernised Process, Current State and Challenges on Biodiesel Production

et al. 2021

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Biodiesel, comprising mono alkyl fatty acid esters or methyl ethyl esters, is an encouraging option to fossil fuels or diesel produced from petroleum; it has comparable characteristics and its use has the potential to diminish carbon dioxide production and greenhouse gas emissions. Manufactured from recyclable and sustainable feedstocks, e.g., oils originating from vegetation, biodiesel has biodegradable properties and has no toxic impact on ecosystems. The evolution of biodiesel has been precipitated by the continuing environmental damage created by the deployment of fossil fuels. Biodiesel is predominantly synthesised via transesterification and esterification procedures. These involve a number of key constituents, i.e., the feedstock and catalytic agent, the proportion of methanol to oil, the circumstances of the reaction and the product segregation and purification processes. Elements that influence the yield and standard of the obtained biodiesel encompass the form and quantity of the feedstock and reaction catalyst, the proportion of alcohol to feedstock, the temperature of the reaction, and its duration. Contemporary research has evaluated the output of biodiesel reactors in terms of energy production and timely biodiesel manufacture. In order to synthesise biodiesel for industrial use efficaciously, it is essential to acknowledge the technological advances that have significant potential in this sector. The current paper therefore offers a review of contemporary progress, feedstock categorisation, and catalytic agents for the manufacture of biodiesel and production reactors, together with modernised processing techniques. The production reactor, form of catalyst, methods of synthesis, and feedstock standards are additionally subjects of discourse so as to detail a comprehensive setting pertaining to the chemical process. Numerous studies are ongoing in order to develop increasingly efficacious techniques for biodiesel manufacture; these acknowledge the use of solid catalytic agents and non-catalytic supercritical events. This review appraises the contemporary situation with respect to biodiesel production in a range of contexts. The spectrum of techniques for the efficacious manufacture of biodiesel encompasses production catalysed by homogeneous or heterogeneous enzymes or promoted by microwave or ultrasonic technologies. A description of the difficulties to be surmounted going forward in the sector is presented.

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“…The wide range of anions and divalent and trivalent cations that can be used to prepare LDH, provide them with a diversity of compositions. In recent decades, LDHs have established themselves as promising materials, due to their properties and applications in a number of fields, such as water remediation [5][6][7], catalysis [8][9][10], drug delivery [11,12], electroactivity [13], biomedicine [14,15], and others. Their applications as anion exchanging solids depend on the interlayer anion and its affinity for the LDH layers.…”

Section: Introductionmentioning

confidence: 99%

Use of Ethylamine, Diethylamine and Triethylamine in the Synthesis of Zn,Al Layered Double Hydroxides

2022

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Amines with two carbon atoms in the organic chain [ethylamine (EA), diethylamine (DEA), triethylamine (TEA)] have been used as precipitant agents to obtain a hydrotalcite-like compound with Zn (II) and Al (III) as layered cations and with nitrate anions in the interlayered region to balance the charge. This Layered Double Hydroxide was prepared following the coprecipitation method, and the effect on the crystal and particle sizes was studied. Also, the effect of submitting the obtained solids to hydrothermal post-synthesis treatment by conventional heating and microwave assisted heating were studied. The obtained solids were exhaustively characterized using several instrumental techniques, such as X-ray diffraction, Thermal Analysis (DTA and TG), Chemical Analysis, Infrared Spectroscopy (FT-IR), determination of Particle Size Distribution and BET-Surface area. Well crystallized solids were obtained showing two possible LDH phases, depending on the orientation of the interlayer anion with respect to the brucite-like layers. The results indicated that there is a certain influence of the amine, when used as a precipitating agent, and as a consequence of the degree of substitution, on the crystallinity and particle size of the final solid obtained. The LDHs obtained using TEA exhibited higher crystallinity, which was improved after a long hydrothermal treatment by conventional heating. Regarding the shape of the particles, the formation of aggregates in the former solid was detected, which could be easily disintegrated using ultrasound treatments, producing solid powder with high crystallinity and small particle size, with homogeneous size distribution.

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K-Modified Co–Mn–Al Mixed Oxide—Effect of Calcination Temperature on N2O Conversion in the Presence of H2O and NOx

Cited by 12 publications

References 69 publications

Effect of Zinc on the Structure and Activity of the Cobalt Oxide Catalysts for NO Decomposition

Effect of Zinc on the Structure and Activity of the Cobalt Oxide Catalysts for NO Decomposition

A Short Review on Catalyst, Feedstock, Modernised Process, Current State and Challenges on Biodiesel Production

Use of Ethylamine, Diethylamine and Triethylamine in the Synthesis of Zn,Al Layered Double Hydroxides

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