Catalytic Oxidation of Alcohols in Water under Atmospheric Oxygen by Use of an Amphiphilic Resin‐Dispersion of a Nanopalladium Catalyst

Abstract

Der idealen Alkoholoxidation einen Schritt näher: Die katalytische Oxidation von Alkoholen in Wasser mit O2 unter Atmosphärendruck wurde mit Pd‐Nanokatalysatoren erreicht, die in einem amphiphilen Harz dispergiert sind (siehe Schema). Dieses Katalysatorsystem vereint in sich hohe katalytische Aktivität (bedingt durch die große Oberfläche der Nanopartikel) und Reaktivität in wässrigem Medium (dank der Amphiphilie der polymeren Matrix).

Efficient Aerobic Oxidation of Alcohols using a Hydrotalcite‐Supported Gold Nanoparticle Catalyst

“…The Au/HT catalyst was also effective for the oxidation of various allylic alcohols (entries 7, 16 and 17) to the corresponding a,b-unsaturated carbonyl compounds. For heteroaromatic alcohols (entries [18][19][20], the catalytic activity may be hampered by strong coordination between the active metal atom and the oxygen (entry 19) or sulfur (entry 20) atoms of the heteroaromatic ring. Surprisingly, the catalyst was tolerant of nitrogen atoms in the heteroaromatic ring (entry 18), giving a high yield of the corresponding ketone.…”

Size‐Dependent Catalytic Activity of Supported Palladium Nanoparticles for Aerobic Oxidation of Alcohols

“…Nevertheless, for the heterogeneous Pd-catalyzed oxidation of alcohols, Pd(0) has been proposed as the active phase in many systems. [7,8,[11][12][13][14][15][16] Solid evidence has been obtained to support this in some research papers. For examples, Mori et al [7b] have confirmed that Pd species over hydroxyapatite are transformed to Pd(0) nanoparticles after the oxidation of 1-phenylethanol via EXAFS measurements; Grunwaldt et al [8] have clarified that the metallic Pd over Al 2 O 3 support is much more active (over 50 times) for the aerobic oxidation of benzyl alcohol than the oxidic Pd species.…”

“…Although a few papers report that palladium oxide can act as the active phase for alcohol oxidation, [9,10] most of recent studies have shown that the supported Pd nanoparticles are excellent catalysts for the selective oxidation of alcohols by oxygen or air. [11][12][13][14][15] For example, Pd/ MgO containing Pd particles with a mean size of 6.9 nm was reported to be efficient for the aerobic oxidation of various alcohols in trifluorotoluene solvent. [11] Pd nanoparticles with a mean diameter of ca.…”

“…9 nm supported on an amphiphilic resin catalyzed the aerobic oxidation of benzylic and allylic alcohols in water medium. [12] Palladium nanoparticles entrapped in aluminum hydroxide with sizes of ca. 2-3 nm or supported on aluminum oxide with diameters of ca.…”

“…[19][20][21][22] In other words, the conversion rate per surface Pd atom in these reactions changes with the size of Pd particles. Although many papers have been contributed to the Pd nanoparticles-catalyzed oxidation of alcohols, [11][12][13][14][15][16][17] studies on the effect of Pd particle size are unexpectedly scarce.…”