Surface Engineering of CeO2 Catalysts: Differences Between Solid Solution Based and Interfacially Designed Ce1−xMxO2 and MO/CeO2 (M = Zn, Mn) in CO2 Hydrogenation Reaction

Rajkumar, T.; Sápi, András; Ábel, Marietta; Kiss, János; Szenti, Imre; Baán, Kornélia; Gómez-Pérez, Juan; Kukovecz, Ákos; Kónya, Zoltán

doi:10.1007/s10562-021-03591-y

Cited by 26 publications

(14 citation statements)

References 78 publications

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“…The samples were formed as nanocrystalline powders with crystallite sizes less than 5 nm [88]. A 10% Zn-containing CeO 2 was found to be an effective catalyst for the CO 2 hydrogenation reaction, ascribed to the highest level of Ce 3+ defects [89]. Although not an elemental substitution, the formation of ZnO-CeO 2 heterojunctions by hydrothermal synthesis has also been studied, where the purposeful growth of the two phases in intimate contact leads to superior visible-light photocatalytic performance [90].…”

Section: Main Group Substituentsmentioning

confidence: 99%

Solvothermal Synthesis Routes to Substituted Cerium Dioxide Materials

et al. 2021

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We review the solution-based synthesis routes to cerium oxide materials where one or more elements are included in place of a proportion of the cerium, i.e., substitution of cerium is performed. The focus is on the solvothermal method, where reagents are heated above the boiling point of the solvent to induce crystallisation directly from the solution. This yields unusual compositions with crystal morphology often on the nanoscale. Chemical elements from all parts of the periodic table are considered, from transition metals to main group elements and the rare earths, including isovalent and aliovalent cations, and surveyed using the literature published in the past ten years. We illustrate the versatility of this synthesis method to allow the formation of functional materials with applications in contemporary applications such as heterogeneous catalysis, electrodes for solid oxide fuel cells, photocatalysis, luminescence and biomedicine. We pick out emerging trends towards control of crystal habit by use of non-aqueous solvents and solution additives and identify challenges still remaining, including in detailed structural characterisation, the understanding of crystallisation mechanisms and the scale-up of synthesis.

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Section: Main Group Substituentsmentioning

confidence: 99%

Solvothermal Synthesis Routes to Substituted Cerium Dioxide Materials

et al. 2021

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“…[ 53 ] The loading of different oxides of Mn on CeO 2 caused the peak shift of CeO 2 towards the higher temperature due to the decreased oxygen mobility. [ 54 ] The lower temperature peak was observed in the MnO 2 /CeO 2 ‐NR catalyst at 359°C, which is lower than that observed in the MnO/CeO 2 ‐NR (437°C) and Mn 2 O 3 /CeO 2 ‐NR (391°C) catalysts. Therefore, it is evident that among all catalysts, the MnO 2 /CeO 2 ‐NR catalyst exhibits the highest redox abilities at the lowest temperature as also validated by the XPS.…”

Section: Resultsmentioning

confidence: 90%

“…When MnO x was introduced, the interaction between Mn 4+ /Mn 3+ and Ce 4+ /Ce 3+ allowed the MnO x / CeO 2 samples to trap and release oxygen efficiently. [54,55] Table 3 shows the amount of hydrogen consumed by the samples in the H 2 -TPR experiments. In all these data, the MnO/CeO 2 -NR showed the lowest hydrogen consumption while MnO 2 /CeO 2 -NR catalyst exhibited highest hydrogen consumption.…”

Section: Hydrogen-temperatureprogrammed Reduction (H 2 -Tpr)mentioning

confidence: 99%

MnO_x/CeO₂ catalysts for the low‐temperature selective catalytic reduction of NO with NH₃

Rao

Sharma

2023

Can J Chem Eng

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CeO2–nanorod support was synthesized by hydrothermal method and different manganese oxides (MnO, MnO2, and Mn2O3) were impregnated over support by the wet‐impregnation forming MnO/CeO2‐NR, MnO2/CeO2‐NRm and Mn2O3/CeO2‐NR. The physico‐chemical properties of the as‐prepared catalysts were analyzed using x‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, x‐ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscope–energy‐dispersive x‐ray spectroscopy (SEM–EDX), hydrogen‐temperature‐programmed reduction (H2‐TPR), and Raman spectroscopy. These catalysts were further analyzed for NO reduction using NH3 as a reducing gas in the temperature range of 50 to 450°C. The results confirmed that MnO2/CeO2‐NR gave the maximum NO conversion (65%) and N2 selectivity (89%) among all catalysts. Further, MnO2/CeO2‐NR catalyst was studied for the effect of MnO2 loading and more than 90% NO conversion and N2 selectivity were obtained in the temperature range of 250 to 300°C.

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“…Overtones of gas-phase CO 2 and OH bonds were observed between 3590 and 3730 cm −1 in both CeO 2 and CZLNS compounds. 63 A broad band in the 1600−800 cm −1 range corresponds to intense C−O vibration modes associated with surface carbonates, carboxylates, formates, and alkoxides. Vibrations related to C−H bonds were detected between 2800 and 3000 cm −1 , with a minor peak at 2858 cm −1 attributed to C−H vibrations of surface formate species, 63 although gas phase CH 4 was not visible as it typically emerges at higher reaction temperatures (>250 °C).…”

Section: = ( )( )mentioning

confidence: 99%

High-Entropy Oxides: A New Frontier in Photocatalytic CO₂ Hydrogenation

Tatar,

Ullah,

Yadav

et al. 2024

ACS Appl. Mater. Interfaces

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Herein, we investigate the potential of nanostructured high-entropy oxides (HEOs) for photocatalytic CO2 hydrogenation, a process with significant implications for environmental sustainability and energy production. Several cerium-oxide-based rare-earth HEOs with fluorite structures were prepared for UV-light driven photocatalytic CO2 hydrogenation toward valuable fuels and petrochemical precursors. The cationic composition profoundly influences the selectivity and activity of the HEOs, where the Ce0.2Zr0.2La0.2Nd0.2Sm0.2O2−δ catalyst showed outstanding CO2 activation (14.4 molCO kgcat –1 h–1 and 1.27 mol CH 3 OH kgcat –1 h–1) and high methanol and CO selectivity (7.84% CH3OH and 89.26% CO) under ambient conditions with 4 times better performance in comparison to pristine CeO2. Systematic tests showed the effect of a high-entropy system compared to midentropy oxides. XPS, in situ DRIFTS, as well as DFT calculation elucidate the synergistic impact of Ce, Zr, La, Nd, and Sm, resulting in an optimal Ce3+/Ce4+ ratio. The observed formate-routed mechanism and a surface with high affinity to CO2 reduction offer insights into the photocatalytic enhancement. While our findings lay a solid foundation, further research is needed to optimize these catalysts and expand their applications.

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Surface Engineering of CeO2 Catalysts: Differences Between Solid Solution Based and Interfacially Designed Ce1−xMxO2 and MO/CeO2 (M = Zn, Mn) in CO2 Hydrogenation Reaction

Cited by 26 publications

References 78 publications

Solvothermal Synthesis Routes to Substituted Cerium Dioxide Materials

Solvothermal Synthesis Routes to Substituted Cerium Dioxide Materials

MnO_x/CeO₂ catalysts for the low‐temperature selective catalytic reduction of NO with NH₃

High-Entropy Oxides: A New Frontier in Photocatalytic CO₂ Hydrogenation

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Surface Engineering of CeO2 Catalysts: Differences Between Solid Solution Based and Interfacially Designed Ce1−xMxO2 and MO/CeO2 (M = Zn, Mn) in CO2 Hydrogenation Reaction

Cited by 26 publications

References 78 publications

Solvothermal Synthesis Routes to Substituted Cerium Dioxide Materials

Solvothermal Synthesis Routes to Substituted Cerium Dioxide Materials

MnOx/CeO2 catalysts for the low‐temperature selective catalytic reduction of NO with NH3

High-Entropy Oxides: A New Frontier in Photocatalytic CO2 Hydrogenation

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MnO_x/CeO₂ catalysts for the low‐temperature selective catalytic reduction of NO with NH₃

High-Entropy Oxides: A New Frontier in Photocatalytic CO₂ Hydrogenation