Effect of indium doping on magnetic properties of cerium oxide nanoparticles

Naik, M.Z.; Salker, A. V.

doi:10.1016/j.matchemphys.2018.03.043

Cited by 11 publications

(9 citation statements)

References 34 publications

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“…13,23,24 Based on this, the experimental observation indicates that indium atoms are doping both CeO 2 and CuO structures. Although detecting Reaction Chemistry & Engineering Paper highly dispersed or non-crystalline indium oxide nanoparticles is not possible by X-ray diffraction, 23,25,26 the linear behavior of expansion/retraction of CeO 2 and CuO unit cells strongly suggests that all indium introduced are homogeneously doping these structures.…”

Section: Resultsmentioning

confidence: 99%

Promoting effects of indium doped Cu/CeO₂ catalysts on CO₂ hydrogenation to methanol

et al. 2022

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Section: Resultsmentioning

confidence: 99%

Promoting effects of indium doped Cu/CeO₂ catalysts on CO₂ hydrogenation to methanol

et al. 2022

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“…In Table , the Ce 3+ /Ce ratios of Mn 6 Ce 0.3 In 0.7 O x and Mn 6 CeO x catalysts are 21.1 and 18.3%, respectively. It indicates that the doping of indium leads to the decrease in the relative content of Ce 4+ , which is because the In 3+ ions inserted into the catalyst replace the position of Ce 4+ , thus changing the oxygen content in the sintering process of the catalyst, transforming Ce 4+ into Ce 3+ . Increasing the concentration of Ce 3+ at the catalyst surface can promote the formation of charge imbalance, unsaturated bonds, and vacancies. , Therefore, the following processes may occur between Ce 4+ and Ce 3+ on the catalyst surface in the SCR reaction: (1) 2CeO 2 → Ce 2 O 3 + O* and (2) Ce 2 O 3 + 1/2O 2 → 2CeO 2 . , In this process, the oxygen in the flue gas is adsorbed and dissociated on the catalyst surface through the oxygen vacancy to produce oxygen with high fluidity and promote the oxidation of NO to NO 2 .…”

Section: Resultsmentioning

confidence: 99%

Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NO_x by NH₃ over MnCeO_x Catalysts: The Promotion Effect and Mechanism

Yang

Zhang

et al. 2022

ACS Omega

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A MnCeInO x catalyst was prepared by a coprecipitation method for denitrification of NH3-SCR (selective catalytic reduction). The catalysts were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analysis, H2 temperature-programmed reduction, and NH3 temperature-programmed desorption. The NH3-SCR activity and H2O and SO2 resistance of the catalysts were evaluated. The test results showed that the SCR and water resistance and sulfur resistance were good in the range of 125–225 °C. The calcination temperature of the Mn6Ce0.3In0.7O x catalyst preparation was studied. The crystallization of the Mn6Ce0.3In0.7O x catalyst was poor when calcined at 300 °C; however, the crystallization is excessive at a 500 °C calcination temperature. The influence of space velocity on the performance of the catalyst is great at 100–225 °C. FTIR test results showed that indium distribution on the surface of the catalyst reduced the content of sulfate on the surface, protected the acidic site of MnCe, and improved the sulfur resistance of the catalyst. The excellent performance of the Mn6Ce0.3In0.7O x catalyst may be due to its high content of Mn4+, surface adsorbed oxygen species, high specific surface area, redox sites and acid sites on the surface, high turnover frequency, and low apparent activation energy.

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“…Em nenhum dos materiais promovidos foram verificados picos referentes ao óxido de índio. De acordo com uma série de autores, a não observância de In2O3 nos difratogramas sugere duas possibilidades, sendo a primeira a de que átomos de índio podem ter sido incorporados como dopantes nas redes estruturais dos demais óxidos e a segunda que as partículas de óxido de índio formadas se encontram não-cristalinas ou mesmo que as nanopartículas desse óxido estejam altamente dispersas, o que impediria a sua detecção pela técnica de difração de raios X devido à seu pequeno diâmetro (CHUAH et al, 1996;GUO et al, 2011;LI, L. et al, 2015;LOU et al, 2014;NAIK;SALKER, 2018 Além disso, à medida que o teor de índio aumenta nos materiais, há um deslocamento dos picos de difração referentes à CeO2 para maiores ângulos, o que, de acordo com Lou et al, (2014) e Naik e Salker, (2018), corrobora a dopagem de átomos de índio na estrutura da céria (LOU et al, 2014;NAIK;SALKER, 2018).…”

Section: Resultsunclassified

“…No entanto, apesar da verificação da dopagem, é importante ressaltar que não é possível comprovar que, necessariamente, todos os átomos de índio introduzidos nos materiais estejam presentes como dopantes na estrutura da céria (LOU et al, 2014;NAIK;SALKER, 2018).…”

Section: Resultsunclassified

“…Parte dos átomos de índio podem ter gerado nanopartículas de óxido de índio segregadas que não poderiam ser detectadas pela técnica da difração de raios X por serem não-cristalinas ou por estarem altamente dispersas devido ao baixo teor desse elemento gerando perfis de difração com intensidade muito baixa (CHUAH et al, 1996;LOU et al, 2014;NAIK;SALKER, 2018).…”

Section: Resultsunclassified

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Estudo dos efeitos de estratégias de manipulação química e estrutural em catalisadores heterogêneos aplicados à hidrogenação de CO>sub<2>/sub< a metanol

Rossi¹

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Nowadays, factors such as population growth, indiscriminate use of water, and contamination of its sources and reservoirs created a need for actions capable of promoting sustainable management of this resource through the conscious use, treatment, and reuse of this resource.Despite the high efficiency of modern treatment systems, some aspects can still be improved, such as the proper destination of the CO2 molecules generated in the anaerobic decomposition stage of organic contaminants, considering that this is the main greenhouse gas whose high concentrations in the atmosphere have led to the recent climate issues. Among the possibilities for this purpose, one of the most promising strategies involves the conversion of this compound into molecules of high added value, such as methanol through hydrogenation reactions through the use of heterogeneous catalysts. In this context, the present work aims to apply strategies for manipulating the chemical and structural nature of catalysts based on copper and zirconia or ceria, in an attempt to achieve considerable improvements in the catalytic performance presented by them. In the first stage, the effects of modifying these materials with indium atoms were studied. As a result, it was found that a considerable increase in methanol selectivity occurred due to indium atoms effects involving changes in the intermediate adsorption and activation energy for specific stages of hydrogenation that are, in general, very high, hindering methanol production. Also, the greater basicity of these materials due to oxygen vacancies was important. In the second stage, the effects of the catalysts encapsulation by porous silica coating were studied. It was observed that the core-shell type materials presented a performance remarkably superior to the other catalysts due to the efficiency of the silica coating in minimizing particles sintering during the heat treatment steps in the synthesis procedure and in reaction steps occurring at high temperatures. In addition to the effects arising from the indium atoms presence, the low dimensions and high homogeneity of the particles obtained enabled considerable values of basicity which have led to high selectivity values for methanol. Also, the high copper dispersion and metallic area values have led to higher CO2 conversion, which associated to the high methanol selectivity, resulted in significant molar productivity for methanol in all tested temperature ranges.

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Effect of indium doping on magnetic properties of cerium oxide nanoparticles

Cited by 11 publications

References 34 publications

Promoting effects of indium doped Cu/CeO₂ catalysts on CO₂ hydrogenation to methanol

Promoting effects of indium doped Cu/CeO₂ catalysts on CO₂ hydrogenation to methanol

Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NO_x by NH₃ over MnCeO_x Catalysts: The Promotion Effect and Mechanism

Estudo dos efeitos de estratégias de manipulação química e estrutural em catalisadores heterogêneos aplicados à hidrogenação de CO>sub<2>/sub< a metanol

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Effect of indium doping on magnetic properties of cerium oxide nanoparticles

Cited by 11 publications

References 34 publications

Promoting effects of indium doped Cu/CeO2 catalysts on CO2 hydrogenation to methanol

Promoting effects of indium doped Cu/CeO2 catalysts on CO2 hydrogenation to methanol

Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NOx by NH3 over MnCeOx Catalysts: The Promotion Effect and Mechanism

Estudo dos efeitos de estratégias de manipulação química e estrutural em catalisadores heterogêneos aplicados à hidrogenação de CO>sub<2>/sub< a metanol

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Promoting effects of indium doped Cu/CeO₂ catalysts on CO₂ hydrogenation to methanol

Promoting effects of indium doped Cu/CeO₂ catalysts on CO₂ hydrogenation to methanol

Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NO_x by NH₃ over MnCeO_x Catalysts: The Promotion Effect and Mechanism