Bismuth glucose oxidation

The reaction scheme is rather complex also in the case of the oxidation of o-xylene (41a, 87a), of the oxidative dehydrogenation of n-butenes over bismuth-molybdenum catalyst (87b), or of ethylbenzene on aluminum oxide catalysts (87c), in the hydrogenolysis of glucose (87d) over Ni-kieselguhr or of n-butane on a nickel on silica catalyst (87e), and in the hydrogenation of succinimide in isopropyl alcohol on Ni-Al2Oa catalyst (87f) or of acetophenone on Rh-Al203 catalyst (87g). Decomposition of n-and sec-butyl acetates on synthetic zeolites accompanied by the isomerization of the formed butenes has also been the subject of a kinetic study (87h). 

Wenkin, M., Touillaux, R., Ruiz, P., Delmon, B., and Devillers, M. (1996) Influence of metallic precursors on the properties of carbon-supported bismuth-promoted palladium catalysts for the selective oxidation of glucose to gluconic acid. Appl. Catal., A, 148, 181-199. 

Bonnemann, H. etal., Selective oxidation of glucose on bismuth-promoted Pd-Pt/C catalysts prepared from N(Oct)4Cl-stabilized Pd-Pt colloids, lnorg. Chim. Acta., 270, 95, 1998. 

M. Besson, F. Lahmer, P. Gallezot, P. Fuertes, and G. Fleche, Catalytic oxidation of glucose on bismuth-promoted palladium catalyst, J. Catal., 152 (1995) 116-121. 

As with platinum, the palladium-catalyzed oxidation of anomeric hydroxyl groups in aldoses is a rather selective process.84 The influence of pH in the Pd-catalyzed oxidation of glucose has been studied. It was observed that the gluconic acid formed, in its free form, reversibly inhibits the oxidation process in acidic media.85 The oxidation of D-glucose has been performed with palladium-on-alumina and with bismuth-containing palladium-on-charcoal in water.85 The selectivity in the air oxidation of... 

Promoting effects of bismuth in carbon-supported bimetallic Pd-Bi catalysts for the selective oxidation of glucose to gluconic acid... 

Glucose can be oxidized to gluconic acid by oxygen (4.38) in the presence of palladium on alumina, a palladium-bismuth catalyst, or a platinum-bismuth catalyst in 99-100% yield.186... 

According to the reactivity scale proposed by Heyns et al. [2-4], oxidation at the anomeric position at C] is easier than for primary or secondary alcohol functions. Selectivity higher than 95 % for aldonic acids were indeed observed in the catalytic oxidation of o-glucose, and of reducing disaccharides such as lactose and maltose. Palladium catalysts or palladium-bismuth catalysts are more selective than platinum because they are less active in the oxidation of primary or secondary alcohol functions. 

The Complex Role of Bismuth as Promoting Element to Inhibit Deactivation of Pd-Bi/C Catalysts in the Selective Oxidation of Glucose to Gluconic Acid... 

In the case of palladium- and platinum-catalyzed oxidation of glucose, bismuth plays a crucial role as a cocatalyst, as discussed in the next section, which has been interpreted by the redox cycle depicted in Figure 21.5 [10]. 

Platinum catalysts supported on activated charcoal, with or without promoters such as bismuth or gold, have been examined for selectivity in the air oxidation of aqueous D-glucose and D-gluconate to glucarate. Palladium(II) has been found to inhibit the oxidation of aldoses by alkaline Fe(CN6) , and by Ce(IV). ... 

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