Kinetics and mechanism of ruthenium(III) catalyzed oxidation of tetrahydrofurfuryl alcohol by cerium(IV) in sulfuric acid media

Abstract

The kinetics and mechanism of ruthenium(III) catalyzed oxidation of tetrahydrofurfuryl alcohol (THFA) by cerium(IV) in sulfuric acid media have been investigated spectrophotometrically in the temperature range 298-313 K. It is found that the reaction is first-order with respect to Ce IV , and exhibits a positive fractional order with respect to THFA and Ru III . The pseudo first-order ([THFA])[Ce IV ] )[Ru III ]) rate constant k obs decreases with the increase of [HSO 4 ) ]. Under the protection of nitrogen, the reaction system can initiate polymerization of acrylonitrile, indicating the generation of free radicals. On the basis of the experimental results, a reasonable mechanism has been proposed and the rate equations derived from the mechanism can explain all the experimental results. From the dependence of k obs on the concentration of HSO 4 ) , CeðSO 4 Þ 2 has been found as the kinetically active species. Furthermore, the rate constants of the rate determining step together with the activation parameters were evaluated.

Role of surfactants on metal mediated cerium(IV) oxidation of valeraldehyde at room temperature and pressure

“…The fact that under the experimental conditions in the absence of Ru(III) ions the reaction practically does take place at a moderate rate [37] supported by an independent experiment. Addition of traces of Ru(III) enhances the rate significantly ( Fig.…”

Selective Aerobic Oxidation of 5-Hydroxymethylfurfural in Water Over Solid Ruthenium Hydroxide Catalysts with Magnesium-Based Supports

“…Hence, homogeneous Ru-complex catalysts have been found to generate aldehydes or ketones in almost quantitative yields when employed in organic solvents [18,19] or ionic liquids [20]. A more preferred way to oxidize HMF involves heterogeneous catalysis, due to ease of catalyst separation in possible industrial processes [1].…”

Kinetics and mechanism of the reaction of catechol with ceric ion in the presence and absence of iridium(III) catalyst in acidic media

“…However, preliminary studies indicate that oxidation of some organic compounds by Ce(IV) in aqueous sulfuric acid is kinetically sluggish, and the process can be efficiently catalyzed by a variety of metal ions. Cerium(IV) oxidation reactions are known to be catalyzed by inorganic ions such as Pd(III), Ru(III), Cr(III), and Ir(III) [16]. Iridium(III) chloride is not a good catalyst in alkaline medium and thus has attracted little attention [17,18].…”