Oxidation of 1-butene by nitrous oxide over manganese(III) and related transition metal oxides

Abstract

The oxidation of 1-butene by nitrous oxide over manganese(II1) oxide was studied in a continuous flow system from 573 to 673 K. Kinetic parameters were derived from the exponential relationship: r = ka P::~P:~;, over reactant partial pressure ranges, 0.30 < PN20 < 2.60 kPa and 0.43 < PC,,, < 8.27 kPa. The reaction mechanism proposed involves a complex sequence of steps which include surface radical reactions. On the basis of a comparison of specific reaction rates, the catalytic activity series for the reaction over a number of transition metal oxides was: Introduction The catalytic performance of manganese oxides in several redox reactions involving hydrocarbons with oxygen or nitrogen oxides has been reported recently. The work has included the oxidation of ethane by nitric oxide over unsupported manganese(II1) oxide (1) and the oxidation of 1-butene and ethane by oxygen over manganese(II1) oxide supported on carbon fibres (2). The results of these experiments pointed to complex surface mechanisms with rate-controlling steps most probably associated with the interactions of species within the adsorbed layer.In the present investigation an attempt has been made to evaluate the kinetics of the catalysis of 1-butene by nitrous oxide over manganese(II1) oxide. Measurements of reaction rates were supplemented by structural analysis. A general comparison of the catalytic activities in the reaction of metal oxides of the first transition series has also been carried out.

Redox Intercalative Polymerization of Aniline in V2O5 Xerogel. The Postintercalative Intralamellar Polymer Growth in Polyaniline/Metal Oxide Nanocomposites Is Facilitated by Molecular Oxygen

“…Simple anilinium salts are not oxidized to polyaniline under the experimental conditions employed here. Therefore, vanadium oxide plays a direct role in this redox event, and this is consistent with its ability to catalyze several oxidation reactions of organic molecules . That oxygen removes electrons from the metal oxide framework can be seen by the decrease of the magnetic susceptibility of the material following this intralamellar polymerization.…”

“…The mechanism of this remarkable all-solid-state intralamellar polymerization must be intimately coupled to the ability of vanadium centers to activate oxygen, which is the primary and ultimate electron acceptor in this process. Simple anilinium salts are not oxidized to polyaniline under the experimental conditions employed here.…”

Preparation, Characterization and Electrochemical Lithium Insertion Into the New Organic–Inorganic Poly(3,4‐Ethylene Dioxythiophene)/V2O5Hybrid

“…The mechanism of this remarkable all-solid-state intra-lamellar polymerization is presumed to be coupled to the ability of vanadium centers to activate oxygen which is the primary electron acceptor in this process. Therefore, vanadium oxide plays a direct role in this redox event, which is consistent with its ability to catalyze several oxidation reactions of organic molecules [37]. A deeper inspection finds that the 985 cm À1 peak increases and the 1015 cm À1 peak decreases inversely as the amount of incorporated polymer augments ( Fig.…”

Synthesis and characterization of a new organo–inorganic poly(3,4-ethylene dioxythiophene) PEDOT/V2O5 nanocomposite by intercalation

“…Therefore, vanadium oxide plays a direct role in this redox event, which is consistent with its ability to catalyze several oxidation reactions of organic molecules. 42 The qualitative differences between spectra of D and E relative to nanocomposites A-C relate to bands at 1218 and 1105 cm 21 owing to the presence of excess PEDOT in these two samples.…”