Aerobic oxidation of 4-tert-butyltoluene over cobalt and manganese supported hexagonal mesoporous silicas as heterogeneous catalysts

Yu, Wei; Zhou, Chun Hui; Tong, Dong Shen; Xu, Tian

doi:10.1016/j.molcata.2012.09.004

Cited by 30 publications

(5 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The origins of the observed redox peaks were assigned on the basis of the peak characteristics and results of previous studies. Mn(III) in Mn 3 O 4 nanoparticles reportedly exhibits O 2– → Mn II (210–250 nm) and O 2– → Mn III (350–390 nm) charge transfer transitions and d–d crystal field transitions in the range of 550–700 nm. − In contrast, Mn(IV) species in MnO 2 exhibit a broad peak in the region of 400 nm and shoulder peaks at approximately 575 and 700 nm . The in situ UV–vis spectral changes for the MnO NPs, in which a continuous peak between 350 and 500 nm and a broad shoulder between 500 and 700 nm were observed, are nearly identical to those previously reported for Mn(IV) species in MnO 2 nanocrystals. , Although no distinct peak was observed for Mn(V), we could not exclude the formation of Mn(V) species during catalysis.…”

Section: Resultsmentioning

confidence: 99%

Mechanistic Investigation of Water Oxidation Catalyzed by Uniform, Assembled MnO Nanoparticles

et al. 2017

View full text Add to dashboard Cite

The development of active water oxidation catalysts is critical to achieve high efficiency in overall water splitting. Recently, sub-10 nm-sized monodispersed partially oxidized manganese oxide nanoparticles were shown to exhibit not only superior catalytic performance for oxygen evolution, but also unique electrokinetics, as compared to their bulk counterparts. In the present work, the water-oxidizing mechanism of partially oxidized MnO nanoparticles was investigated using integrated in situ spectroscopic and electrokinetic analyses. We successfully demonstrated that, in contrast to previously reported manganese (Mn)-based catalysts, Mn(III) species are stably generated on the surface of MnO nanoparticles via a proton-coupled electron transfer pathway. Furthermore, we confirmed as to MnO nanoparticles that the one-electron oxidation step from Mn(II) to Mn(III) is no longer the rate-determining step for water oxidation and that Mn(IV)═O species are generated as reaction intermediates during catalysis.

show abstract

Section: Resultsmentioning

confidence: 99%

Mechanistic Investigation of Water Oxidation Catalyzed by Uniform, Assembled MnO Nanoparticles

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Based on the literature reports and experimental results [ 19 , 27 , 31 , 45 , 50 , 51 ], we propose a possible reaction mechanism ( Scheme 4 ). First, benzylamine undergoes a single-electron oxidation process at the anode to form the nitrogen radical cationic intermediate I .…”

Section: Resultsmentioning

confidence: 98%

Selective Oxidative Cleavage of Benzyl C–N Bond under Metal-Free Electrochemical Conditions

Huang,

Li,

Liu

et al. 2024

Molecules

View full text Add to dashboard Cite

With the growing significance of green chemistry in organic synthesis, electrochemical oxidation has seen rapid development. Compounds undergo oxidation–reduction reactions through electron transfer at the electrode surface. This article proposes the use of electrochemical methods to achieve cleavage of the benzyl C–N bond. This method selectively oxidatively cleaves the C–N bond without the need for metal catalysts or external oxidants. Additionally, primary, secondary, and tertiary amines exhibit good adaptability under these conditions, utilizing water as the sole source of oxygen.

show abstract

“…Moreover, it has several features, such as being highly active, stable, inexpensive, and ecofriendly catalyst [51][52][53][54][55][56]. However, different types of manganese oxide, mixed manganese oxide, and noble metal doped/supported Mn oxides were widely employed for the catalytic oxidation of numerous organic substrates, for instance, oxidation of naphthalene to carbon dioxide [57], oxidation of carbon monoxide to CO 2 [58,59], oxidation of toluene to CO 2 [60], oxidation of ethylene and propylene to CO 2 [61], oxidation of cyclohexane to cyclohexanol and cyclohexanone [62], oxidation of alkyl aromatics to ketones [63], oxidation of 4-tert-butyltoluene to 4-tert-butylbenzaldehyde [64], and oxidation of formaldehyde to CO 2 [65].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Relative Study on the Catalytic Activity of Zinc Oxide Nanoparticles Doped MnCO₃, –MnO₂, and –Mn₂O₃ Nanocomposites for Aerial Oxidation of Alcohols

Assal

Kuniyil

Shaik

et al. 2017

Journal of Chemistry

View full text Add to dashboard Cite

Zinc oxide nanoparticles doped manganese carbonate catalysts [ % ZnO x -MnCO 3 ] (where = 0-7) were prepared via a facile and straightforward coprecipitation procedure, which upon different calcination treatments yields different manganese oxides, that is, [ % ZnO x -MnO 2 ] and [ % ZnO x -Mn 2 O 3 ]. A comparative catalytic study was conducted to evaluate the catalytic efficiency between carbonates and oxides for the selective oxidation of secondary alcohols to corresponding ketones using molecular oxygen as a green oxidizing agent without using any additives or bases. The prepared catalysts were characterized by different techniques such as SEM, EDX, XRD, TEM, TGA, BET, and FTIR spectroscopy. The 1% ZnO x -MnCO 3 calcined at 300 ∘ C exhibited the best catalytic performance and possessed highest surface area, suggesting that the calcination temperature and surface area play a significant role in the alcohol oxidation. The 1% ZnO x -MnCO 3 catalyst exhibited superior catalytic performance and selectivity in the aerial oxidation of 1-phenylethanol, where 100% alcohol conversion and more than 99% product selectivity were obtained in only 5 min with superior specific activity (48 mmol⋅g −1 ⋅h −1 ) and 390.6 turnover frequency (TOF). The specific activity obtained is the highest so far (to the best of our knowledge) compared to the catalysts already reported in the literatures used for the oxidation of 1-phenylethanol. It was found that ZnO x nanoparticles play an essential role in enhancing the catalytic efficiency for the selective oxidation of alcohols. The scope of the oxidation process is extended to different types of alcohols. A variety of primary, benzylic, aliphatic, allylic, and heteroaromatic alcohols were selectively oxidized into their corresponding carbonyls with 100% convertibility without overoxidation to the carboxylic acids under base-free conditions.

show abstract

Aerobic oxidation of 4-tert-butyltoluene over cobalt and manganese supported hexagonal mesoporous silicas as heterogeneous catalysts

Cited by 30 publications

References 46 publications

Mechanistic Investigation of Water Oxidation Catalyzed by Uniform, Assembled MnO Nanoparticles

Mechanistic Investigation of Water Oxidation Catalyzed by Uniform, Assembled MnO Nanoparticles

Selective Oxidative Cleavage of Benzyl C–N Bond under Metal-Free Electrochemical Conditions

Synthesis, Characterization, and Relative Study on the Catalytic Activity of Zinc Oxide Nanoparticles Doped MnCO₃, –MnO₂, and –Mn₂O₃ Nanocomposites for Aerial Oxidation of Alcohols

Contact Info

Product

Resources

About

Aerobic oxidation of 4-tert-butyltoluene over cobalt and manganese supported hexagonal mesoporous silicas as heterogeneous catalysts

Cited by 30 publications

References 46 publications

Mechanistic Investigation of Water Oxidation Catalyzed by Uniform, Assembled MnO Nanoparticles

Mechanistic Investigation of Water Oxidation Catalyzed by Uniform, Assembled MnO Nanoparticles

Selective Oxidative Cleavage of Benzyl C–N Bond under Metal-Free Electrochemical Conditions

Synthesis, Characterization, and Relative Study on the Catalytic Activity of Zinc Oxide Nanoparticles Doped MnCO3, –MnO2, and –Mn2O3 Nanocomposites for Aerial Oxidation of Alcohols

Contact Info

Product

Resources

About

Synthesis, Characterization, and Relative Study on the Catalytic Activity of Zinc Oxide Nanoparticles Doped MnCO₃, –MnO₂, and –Mn₂O₃ Nanocomposites for Aerial Oxidation of Alcohols