O-vacancy-rich porous MnO2 nanosheets as highly efficient catalysts for propane catalytic oxidation

Wu, Shipeng; Liu, Huimin; Huang, Zhen; Xu, Hualong; Shen, Wei

doi:10.1016/j.apcatb.2022.121387

Cited by 133 publications

(71 citation statements)

References 57 publications

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“…For Mn 2 O 3 -B and Mn 2 O 3 -H, the EPR signals are very weak and no obvious vibration peaks can be observed, indicating the low density of surface oxygen vacancies on pure Mn 2 O 3 samples. On the contrary, the signal at g = 2.003 on 5%CeMn-H is obvious, which is attributed to the electrons trapped on oxygen vacancies in the sample. , Therefore, the addition of cerium is a good way to generate surface oxygen vacancies on pure Mn 2 O 3 , further promoting oxygen activation ability to achieve better catalytic oxidation performance.…”

Section: Resultsmentioning

confidence: 98%

“…Figure a displays the O 1s spectra of Mn 2 O 3 -B, Mn 2 O 3 -H, and 5%CeMn-H, which can be fitted with three peaks at 529.4–530.2, 530.9–531.6, and >532.6 eV, corresponding to lattice oxygen (O latt ), surface adsorbed oxygen (O sur ), and surface adsorbed water (O wat ), respectively. ,, The contents of different surface oxygen species are summarized in Table . Among them, adsorbed oxygen species (O 2 – , O – , and O 2 2– ) are the most active for the oxidation process and will be easier to regenerate by gaseous oxygen at low temperatures. , As expected, with HPMC-assisted gel combustion, more adsorbed oxygen species can be achieved over both Mn 2 O 3 -H and 5%CeMn-H, which would be highly active in the process of VOC oxidation.…”

Section: Resultsmentioning

confidence: 99%

“…On the contrary, the signal at g = 2.003 on 5%CeMn-H is obvious, which is attributed to the electrons trapped on oxygen vacancies in the sample. 56,61 Therefore, the addition of cerium is a good way to generate surface oxygen vacancies on pure Mn 2 O 3 , further promoting oxygen activation ability to achieve better catalytic oxidation performance.…”

Section: Catalytic Performance Of As-prepared Catalystsmentioning

confidence: 99%

“…As a result, two clear desorption peaks can be observed in both porous Mn 2 O 3 -H and CeMn-H, where the desorption peak at 400−600 °C can be attributed to the desorption peak of lattice oxygen species on the surface, and the peak above 600 °C is related to bulk lattice oxygen. 50,56 According to Mars−Van Krevelen model, surface lattice oxygen on the oxide participates in the oxidation of toluene molecules by the formation of oxygen vacancies, which can be compensated by gaseous oxygen and then dissociated to form active oxygen for reaction recycling. However, Mn 2 O 3 -B prepared by direct calcination without HPMC only has a desorption peak at higher temperatures, demonstrating that the porous manganese oxide prepared by HPMC-assisted gel combustion has more active surface oxygen for deep oxidation VOCs like toluene.…”

Section: Catalytic Performance Of As-prepared Catalystsmentioning

confidence: 99%

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Fabrication of Hierarchical Porous Metal Oxides by the HPMC-Assisted Gel Combustion Strategy: Incorporation of Nanoceria into Cookie-like Mn₂O₃ with Enhanced Oxidation Activity and Excellent Water Resistance

Cao

Zhang

et al. 2023

Ind. Eng. Chem. Res.

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Constructing nonprecious metal oxide catalysts with a hierarchical porous structure by a simple method for the deep catalytic oxidation of toxic volatile organic compounds at low temperatures is of great value and significance. In this work, a porous manganese trioxide catalyst (Mn 2 O 3 -H) was prepared by a hydroxypropyl methylcellulose-assisted combustion synthesis strategy for catalytic complete oxidation of gaseous toluene. Benefiting from the rich porous nanostructure, Mn 2 O 3 -H has much higher specific surface area and active site density, resulting in better low-temperature reducibility and oxygen activation ability than blank Mn 2 O 3 formed by direct calcination. With this sol−gel combustion process, CeO 2 nanoparticles could be successfully introduced to form cookie-like Ce−Mn composite oxide with a hierarchical porous nanostructure, which builds the strong interaction of CeO 2 − Mn 2 O 3 to weaken Mn−O with more active defects. Among Ce-doped catalysts, 5% CeMn-H shows the best catalytic activity in toluene oxidation with 90% conversion temperature at 242 °C under a weight hour space velocity of 60,000 mL•g −1 •h −1 , which is about 30 and 133 °C lower than that of Mn 2 O 3 -H and Mn 2 O 3 -B, respectively. This advantage is also shown in other typical hydrocarbons such as propylene and propane. Moreover, the as-prepared Ce-doped catalyst exhibits excellent stability and water resistance ability. This simple robust sol−gel combustion method will provide valuable enlightenment for designing porous catalysts with high performance for related catalytic reactions.

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Catalytic Performance Of As-prepared Catalystsmentioning

confidence: 99%

Section: Catalytic Performance Of As-prepared Catalystsmentioning

confidence: 99%

See 2 more Smart Citations

Fabrication of Hierarchical Porous Metal Oxides by the HPMC-Assisted Gel Combustion Strategy: Incorporation of Nanoceria into Cookie-like Mn₂O₃ with Enhanced Oxidation Activity and Excellent Water Resistance

Cao

Zhang

et al. 2023

Ind. Eng. Chem. Res.

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“…Notably, there is an extra small peak at ca. 206 °C, corresponding to the reduction of surface chemisorbed oxygen species . The initial H 2 reduction temperature dropped from 206 to 170 °C after the deposition of Cu species on Kln/Mn, indicating a more vital oxidation ability of KM@0.10CuO-NO 3 .…”

Section: Resultsmentioning

confidence: 99%

Biomimetic Tremelliform Ultrathin MnO₂/CuO Nanosheets on Kaolinite Driving Superior Catalytic Oxidation: An Example of CO

Liu

Wang

Han

et al. 2022

ACS Appl. Mater. Interfaces

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Highly efficient three-dimensional (3D) kaolinite/MnO2–CuO (KM@CuO–NO3) catalysts were synthesized by a mild biomimetic strategy. Kaolinite flakes were uniformly wrapped by ultrathin tremelliform MnO2 nanosheets with thicknesses of around 1.0–1.5 nm. Si–O and Al–O groups in kaolinite hosted MnO2 nanosheets to generate a robust composite structure. The ultrathin MnO2 lamellar structure exhibited excellent stability even after calcination above 350 °C. Kaolinite/MnO2 exhibited abundant edges, sharp corners, and interconnected diffusion channels, which are superior to the common stacked structure. Open channels guaranteed fast transportation and migration of CO and O2 during CO oxidation. The synthesized KM@CuO–NO3 achieved a 90% CO conversion efficiency at a relatively low temperature (110 °C). Furthermore, the abundant oxygen vacancies on KM@CuO-NO3 assisted the adsorption and activation of oxygen species and thus enhanced the oxygen mobility and reactivity in the catalytic process. The mechanism results suggest that CuO introduced to the catalyst not only acted as CO active sites but also weakened the Mn–O bond, subsequently improved the mobilities of the oxygen species, which was found to contribute to its high activity for CO oxidation. This study provides new conceptual insights into rationally regulating structural assembly between transition metal oxides and natural minerals for high-performance catalysis reactions.

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All‐In‐One Self‐Floating Wood‐Based Solar‐Thermal Evaporators for Simultaneous Solar Steam Generation and Catalytic Degradation

Zhang,

Qu,

et al. 2024

Adv Funct Materials

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Solar‐driven steam generation has emerged as a sustainable technology for addressing freshwater scarcity. However, significant challenges still exist in developing high‐performance, multifunctional evaporators that are adept at both efficiently evaporating water and degrading pollutants, primarily because of the trade‐offs among functional designs. Here, a self‐floating solar evaporator is reported by functionalizing balsa wood with solar‐thermal conversion material carbon nanotubes and catalytic manganese dioxide (MnO2) nanoflowers for simultaneous solar evaporation and pollutant degradation. MnO2 nanoflowers are rich in oxygen vacancies that can effectively activate peroxymonosulfate to generate reactive oxygen species for efficient organic pollutant degradation. A distinctive non‐wetted porous interior structure and a precisely targeted water pathway are spontaneously established in the multifunctional evaporator, ensuring fast water supply, thermal insulation, efficient mass transfer, and high buoyancy. The resulting evaporators successfully combine an impressive evaporation rate of 2.74 kg m−2 h−1, a high pollutant degradation efficiency (98.3% for 100 mg L−1 tetracycline and 97.4% for 200 mg L−1 Methyl orange), and stable self‐floating and self‐standing capabilities that ensure long‐term operation stability even in complex real‐world environments. This work provides an approach to design multifunctional solar evaporators, ensuring strong alignment with practical requirements while expanding their potential application scenarios.

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O-vacancy-rich porous MnO2 nanosheets as highly efficient catalysts for propane catalytic oxidation

Cited by 133 publications

References 57 publications

Fabrication of Hierarchical Porous Metal Oxides by the HPMC-Assisted Gel Combustion Strategy: Incorporation of Nanoceria into Cookie-like Mn₂O₃ with Enhanced Oxidation Activity and Excellent Water Resistance

Fabrication of Hierarchical Porous Metal Oxides by the HPMC-Assisted Gel Combustion Strategy: Incorporation of Nanoceria into Cookie-like Mn₂O₃ with Enhanced Oxidation Activity and Excellent Water Resistance

Biomimetic Tremelliform Ultrathin MnO₂/CuO Nanosheets on Kaolinite Driving Superior Catalytic Oxidation: An Example of CO

All‐In‐One Self‐Floating Wood‐Based Solar‐Thermal Evaporators for Simultaneous Solar Steam Generation and Catalytic Degradation

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O-vacancy-rich porous MnO2 nanosheets as highly efficient catalysts for propane catalytic oxidation

Cited by 133 publications

References 57 publications

Fabrication of Hierarchical Porous Metal Oxides by the HPMC-Assisted Gel Combustion Strategy: Incorporation of Nanoceria into Cookie-like Mn2O3 with Enhanced Oxidation Activity and Excellent Water Resistance

Fabrication of Hierarchical Porous Metal Oxides by the HPMC-Assisted Gel Combustion Strategy: Incorporation of Nanoceria into Cookie-like Mn2O3 with Enhanced Oxidation Activity and Excellent Water Resistance

Biomimetic Tremelliform Ultrathin MnO2/CuO Nanosheets on Kaolinite Driving Superior Catalytic Oxidation: An Example of CO

All‐In‐One Self‐Floating Wood‐Based Solar‐Thermal Evaporators for Simultaneous Solar Steam Generation and Catalytic Degradation

Contact Info

Product

Resources

About

Fabrication of Hierarchical Porous Metal Oxides by the HPMC-Assisted Gel Combustion Strategy: Incorporation of Nanoceria into Cookie-like Mn₂O₃ with Enhanced Oxidation Activity and Excellent Water Resistance

Fabrication of Hierarchical Porous Metal Oxides by the HPMC-Assisted Gel Combustion Strategy: Incorporation of Nanoceria into Cookie-like Mn₂O₃ with Enhanced Oxidation Activity and Excellent Water Resistance

Biomimetic Tremelliform Ultrathin MnO₂/CuO Nanosheets on Kaolinite Driving Superior Catalytic Oxidation: An Example of CO