CeO₂-modified Au@SBA-15 nanocatalysts for liquid-phase selective oxidation of benzyl alcohol

Abstract

Tuning the interfacial perimeter and structure is crucial to understanding the origin of catalytic performance. This paper describes the design, characterization, and application of CeO2 modified Au@SBA-15 (Au-CeO2@SBA-15) catalysts in selective oxidation of benzyl alcohol. The reaction results showed that Au-CeO2@SBA-15 catalysts exhibited higher catalytic activity compared with Au@SBA-15 and Au/CeO2 catalysts under identical conditions along with the high selectivity towards benzaldehyde (>99%). The turnover frequency of benzyl alcohol over the Au-100CeO2@SBA-15 catalyst is about nine-fold and four-fold higher than those of Au@SBA-15 and Au/CeO2 catalysts, respectively. The supported catalysts were characterized by N2 adsorption-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, scanning transmission electron microscopy-energy dispersive spectrometry, and X-ray photoelectron spectroscopy. It was found that the Au and small CeO2 nanoparticles (∼5 nm) were homogeneously mixed in the channels of SBA-15, which led to an increase in the interfacial area between Au and CeO2 and consequently a better catalytic performance of Au-CeO2@SBA-15 catalysts for the selective oxidation of benzyl alcohol to benzaldehyde compared with that of Au/CeO2. The prevention of agglomeration and leaching of Au nanoparticles by restricting them inside the mesopores of SBA-15 was conducive to the stable existence of large quantities of Au-CeO2 interface, which leads to high stability of the Au-CeO2@SBA-15 catalyst.

Selective liquid phase benzyl alcohol oxidation over Cu-loaded LaFeO3 perovskite

“…The significant activity behaviour (~ 99 % conversion with 100 % selectivity at 80 °C after 3 h in acetonitrile media that corresponds to a TON of 481) of our presently reported copper based perovskite catalyst Cu10LaFe becomes even more evident when this system is compared with the already reported catalysts in the literature. Apart from the general functioning of most of the catalyst materials in a solvent medium, there are several types of catalyst systems that are reported to work under a solvent free condition [17,19,23,24,26], under an aerobic condition [16,18,23,[32][33][34][36][37][38][39][40] and in the vapour phase [41][42][43]. To cite some of these different (in the sense that these cannot be directly compared to the present catalyst) types of catalytic systems, Ru/TiO 2 catalysts prepared by a wet chemical route with a low loading of Ru has been reported to show good activity behaviour with molecular oxygen [18].…”

Ag2O Nanoparticles-Doped Manganese Immobilized on Graphene Nanocomposites for Aerial Oxidation of Secondary Alcohols

“…Fortunately, these alcohols are selectively oxidized to their respective aldehydes employing optimum conditions. It is clear that the catalytic system was found to be also effective for the selective oxidation of primary aromatic alcohols (Table 6, entries [10][11][12][13][14][15][16][17][18][19][20][21][22]. In addition, selectivity toward aldehydes is more than 99%, because there no over-oxidation to acids occurred, except that the aldehyde was observed.…”

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

“…In order to exploit the applicability of the present catalytic system and to generalize the scope of the oxidation process, the oxidation reaction has extended to various types of alcohol such as primary aromatic, allylic, heteroaromatic, and aliphatic alcohols. Generally, all primary aromatic alcohols could be oxidized rapidly to the corresponding aldehydes with complete conversions within very short reaction times (Table 6, entries [10][11][12][13][14][15][16][17][18][19][20][21][22]. Moreover, more than 99% selectivity to corresponding aldehydes has been achieved in most of oxidation reactions and no other products were detected in the reaction mixture because no overoxidation to carboxylic acids occurred.…”

“…In contrast, using clean and low cost oxidizing agents, such as aqueous hydrogen peroxide and particularly molecular oxygen to produce water, is the only side product and has gained growing interest from the sustainable and green chemistry point of views [14,15]. In this context, noble metals such as gold [16][17][18][19][20], palladium [21], platinum [22][23][24], ruthenium [25,26], and rhodium [27,28] have been used as a heterogeneous catalyst for the alcohol oxidation with high catalytic activities and selectivities. Beside their high costs, these precious metals also have serious toxicity issues and difficulty in preparation and rarity of these noble metals makes these catalysts 2 Journal of Chemistry impractical for industrial applications [29,30].…”