A novel generalized metal dissolution approach for the synthesis of mixed valent mesoporous metal oxides

Thalgaspitiya, Wimalika R.K.; Kapuge, Tharindu Kankanam; Rathnayake, Dinithi; He, Jian; Willis, William S.; Suib, Steven L.

doi:10.1016/j.mattod.2019.10.024

Cited by 12 publications

(17 citation statements)

References 105 publications

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“…Correspondingly, the high-resolution transmission electron microscopy (HRTEM) image of solid MoO 3 shows a smooth surface with lattice fringes of the (200) crystal face of MoO 3 (Figure 1c,f), while a large amount of hollow mesopores is generated on CeO 2 and MoO 3 /CeO 2 through the accumulation of nanoparticles (Figure 1d,e). 46 O I and O III /O I peak area ratios of MoO 3 /CeO 2 are higher than those of CeO 2 (24% vs 20%, 10% vs 8%) (Table S1).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…MoO 3 shows a type I isotherm, and the specific surface area and pore volume are 3.2 m 2 g –1 and 0.011 cm 3 g –1 , respectively. Correspondingly, the high-resolution transmission electron microscopy (HRTEM) image of solid MoO 3 shows a smooth surface with lattice fringes of the (200) crystal face of MoO 3 (Figure c,f), while a large amount of hollow mesopores is generated on CeO 2 and MoO 3 /CeO 2 through the accumulation of nanoparticles (Figure d,e) Figure g,h reveals the same representative polycrystals with two adjacent lattice fringes of 0.31–0.33 nm, which are equivalent to those of the (111) crystal face of CeO 2 .…”

Section: Resultsmentioning

confidence: 99%

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Controlled Synthesis of Dibenzenetriol and Diquinone from 1,2,4-Benzenetriol by Catalytic Aerobic Oxidation

Zhong

Cai

et al. 2022

ACS Sustainable Chem. Eng.

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The preparation of diphenol and diquinone from biomass is significant for sustainable fine chemicals, which are currently developed from fossil-based or ligninderived phenols. Herein, a class of transition-metal oxides (CeO 2 , MoO 3 , and MoO 3 / CeO 2 ) with different O 2 activation abilities and basicity was prepared for the catalytic aerobic oxidation of 1,2,4-benzenetriol to dibenzenetriol and diquinone. CeO 2 with a moderate O 2 activation ability and basicity shows a 98% yield of dibenzenetriol upon the oxidative coupling reaction, whereas MoO 3 /CeO 2 with a strong O 2 activation ability and basicity results in a highly efficient synthesis of diquinone with a 79% yield via tandem oxidative coupling and further oxidation reactions. Meanwhile, these metal oxides exhibit stable recycling performance and reusability. This work can lead to the facile and efficient synthesis of dibenzenetriol and diquinone, which is unattainable with the previous ligninbased route.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Controlled Synthesis of Dibenzenetriol and Diquinone from 1,2,4-Benzenetriol by Catalytic Aerobic Oxidation

Zhong

Cai

et al. 2022

ACS Sustainable Chem. Eng.

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“…The XP spectrum of oxygen showed two bands at 530.3 and 531.4 eV, which correspond to bulk lattice oxygen of the mixed oxide (O 2– ) and chemisorbed oxygen species (O – , O 2 – , etc. ) The surface acid site densities calculated by using neutralization ion-exchange methods − showed the presence of a higher density of moderate/weak acid sites in the mixed metal oxide (19.3 mmol/g) compared to pure MoO 3 (8.0 mmol/g) and pure WO 3 (12.1 mmol/g) (Table ).…”

Section: Resultsmentioning

confidence: 99%

“…The neutralization ion-exchange method was used to calculate strong and weak/moderate acid site densities. − To calculate strong acid site density, the catalyst (100 mg) was stirred overnight with 1 M NaCl (100 mL). The supernatant was separated, and a 25 mL aliquot was titrated with 0.1 M NaOH in the presence of phenolphthalein indicator.…”

Section: Methodsmentioning

confidence: 99%

Mesoporous Molybdenum–Tungsten Mixed Metal Oxide: A Solid Acid Catalyst for Green, Highly Efficient sp³–sp² C–C Coupling Reactions

Thalgaspitiya

Kapuge

et al. 2020

ACS Appl. Mater. Interfaces

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A mesoporous molybdenum tungsten mixed metal oxide with high surface area (173 m2/g) was synthesized by using metal dissolution coupled with a surfactant assisted reverse micelle formation synthesis method. Comprehensive characterization of the mixed oxide was performed by using PXRD, Raman, BET, SEM, EDX, TEM, and XPS. Thus, the formation of α-Mo0.5W0.5O3 with a homogeneous distribution of Mo and W throughout the material was seen. Furthermore, multiple oxidation states of molybdenum (Mo6+ and Mo5+) and a single oxidation state of tungsten (W6+) were observed. The weak/moderate acidic sites present in the mixed metal oxide resulted in excellent catalytic properties toward the sp3–sp2 carbon–carbon coupling reactions. The coupling of benzyl alcohol and toluene was completed within 15 min at 110 °C with 99% yield.

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“…Molybdenum forms the basis of many heterogeneous catalytic systems that are very effective in controlling the rate and selectivity of a wide range of organic transformation reactions. − Besides catalysis, molybdenum-based materials show great applications in energy storage, optoelectronics, gas sensors, adsorption, and electrochemistry among others. − Molybdenum oxides and molybdenum sulfides are the most frequently used catalysts, while bromide, boride, nitride, phosphide, and carbide systems have also gotten much attention recently . Molybdenum oxides provide a series of oxidation states from 0 to +6, which are widely used for electrophilic addition, oxidation, and coupling reactions .…”

Section: Introductionmentioning

confidence: 99%

Highly Mesoporous MoO₃ Catalysts for Electrophilic Aromatic Substitution

Shubhashish

Wijenayake

Huang

et al. 2022

ACS Appl. Mater. Interfaces

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Herein, a straightforward synthesis method for highly mesoporous molybdenum oxide has been demonstrated via use of inverse micelles and molybdenum-oxo cluster formation. The synthesized catalyst is stable, crystalline, and MoO3 phase pure, as confirmed through thermogravimetric analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. Further results from electron paramagnetic resonance, Raman spectroscopy, and UV–vis spectroscopy confirm the MoO3 phase purity. Chemisorption studies reveal that the synthesized material is 65 times more active than its commercial parts. The quantitative value of ammonia chemisorption for the synthesized catalyst is 1270 μmol/g, whereas the commercial catalyst only gives 22 μmol/g. These materials were tested for electrophilic substitution reactions since they are excellent solid acid. Electrophilic substitution of benzyl alcohol with toluene gives a >99% conversion with ∼80% of selectivity toward the methyl diphenylmethane product. The turnover number and turnover frequency values were calculated to be as high as 115 and 38, respectively. A substrate scope study shows that the reaction has preference toward electron-donating groups, whereas electron-withdrawing groups block the reaction. Based on the obtained results, a mechanism has been proposed.

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A novel generalized metal dissolution approach for the synthesis of mixed valent mesoporous metal oxides

Cited by 12 publications

References 105 publications

Controlled Synthesis of Dibenzenetriol and Diquinone from 1,2,4-Benzenetriol by Catalytic Aerobic Oxidation

Controlled Synthesis of Dibenzenetriol and Diquinone from 1,2,4-Benzenetriol by Catalytic Aerobic Oxidation

Mesoporous Molybdenum–Tungsten Mixed Metal Oxide: A Solid Acid Catalyst for Green, Highly Efficient sp³–sp² C–C Coupling Reactions

Highly Mesoporous MoO₃ Catalysts for Electrophilic Aromatic Substitution

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A novel generalized metal dissolution approach for the synthesis of mixed valent mesoporous metal oxides

Cited by 12 publications

References 105 publications

Controlled Synthesis of Dibenzenetriol and Diquinone from 1,2,4-Benzenetriol by Catalytic Aerobic Oxidation

Controlled Synthesis of Dibenzenetriol and Diquinone from 1,2,4-Benzenetriol by Catalytic Aerobic Oxidation

Mesoporous Molybdenum–Tungsten Mixed Metal Oxide: A Solid Acid Catalyst for Green, Highly Efficient sp3–sp2 C–C Coupling Reactions

Highly Mesoporous MoO3 Catalysts for Electrophilic Aromatic Substitution

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Product

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Mesoporous Molybdenum–Tungsten Mixed Metal Oxide: A Solid Acid Catalyst for Green, Highly Efficient sp³–sp² C–C Coupling Reactions

Highly Mesoporous MoO₃ Catalysts for Electrophilic Aromatic Substitution