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

Abstract

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.

NiFe2O4nanoparticles: an efficient and reusable catalyst for the selective oxidation of benzyl alcohol to benzaldehyde under mild conditions

“…29 Also, the literature reports suggest that the oxidation of aliphatic alcohols is much more difficult than the oxidation of aromatic alcohols. 30,31,51,52 From these results, we conclude that the experimental conditions of the present catalyst system are not so favourable for the oxidation of aliphatic alcohols but very effective for selective oxidation of benzylic alcohols.…”

“…But satisfactory results in terms of selectivity were attained in only a few cases. [29][30][31][32][33][34] Therefore, the demands of efficient and selective catalysts are the driving forces for the researchers to synthesize new catalysts.…”

Selective Catalytic Oxidation of Toluene to Benzaldehyde: Effect of Aging Time and Calcination Temperature Using CuxZnyO Mixed Metal Oxide Nanoparticles

“…Hence, based on the above literature reports and in continuation of our studies towards preparation of various catalysts for different conversion reactions [36][37][38][39][40][41][42], in the present work we report the synthesis of Cu x Zn y O mixed oxide by coprecipitation with varied aging time and calcination temperature. The prepared catalysts were characterized by various techniques such as XRD, XPS, FT-IR, TGA, SEM, and TEM.…”

Synthesis, characterization and catalytic performance of ZnO–CeO2 nanoparticles in wet oxidation of wastewater containing chlorinated compounds

“…The interaction of CeO 2 with & Anushree anushreejatrana@gmail.com low valent element strongly enhances its redox property, which leads to the promoted oxidation efficiency (Anushree and Kumar 2015a; Arena 2014). We have selected ZnO-CeO 2 by taking its wide catalytic applications in consideration (Habibi and Fakhrpor 2016;Faisal et al 2011;Assal et al 2017). Here we investigate the potential of ZnO-CeO 2 nanoparticles toward oxidative abatement of pollutants present in paper industry wastewater.…”