Recent advances in transition metal catalyzed oxidation of organic substrates with molecular oxygen.

Ceria has been the subject of thorough investigations, mainly because of its use as an active component of catalytic converters for the treatment of exhaust gases. However, ceria-based catalysts have also been developed for different applications in organic chemistry. The redox and acid-base properties of ceria, either alone or in the presence of transition metals, are important parameters that allow to activate complex organic molecules and to selectively orient their transformation. Pure ceria is used in several organic reactions, such as the dehydration of alcohols, the alkylation of aromatic compounds, ketone formation, and aldolization, and in redox reactions. Ceria-supported metal catalysts allow the hydrogenation of many unsaturated compounds. They can also be used for coupling or ring-opening reactions. Cerium atoms can be added as dopants to catalytic system or impregnated onto zeolites and mesoporous catalyst materials to improve their performances. This Review demonstrates that the exceptional surface (and sometimes bulk) properties of ceria make cerium-based catalysts very effective for a broad range of organic reactions.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/cssc.201000054

Ceria‐Based Solid Catalysts for Organic Chemistry

This review is a survey of the main facts and concepts appeared in the last years on kinetics of oxidative dehydrogenation (ODH) of ethane, propane, butane and isobutane. The accent is put on the mechanisms and the kinetic models used for the description of this reaction. The main catalysts for ODH of light alkanes and the specific features of each type of alkane are discussed. Influence of the type of supports, promoters, acid–base properties, type of oxygen on the performance of ODH reaction is also discussed. No clear interpretation regarding the mode of alkane activation of each stage of this reaction can be derived from the survey of the literature and the problems which are still waiting for the solution or need further studies are described.

Kinetics of Oxidative Dehydrogenation of C2‐C3 Alkanes on Oxide Catalysts

Chromium Oxide/Alumina Catalysts in Oxidative Dehydrogenation of Isobutane☆

https://pubs.rsc.org/en/content/articlepdf/2010/gc/c000191k

Sustainable selective oxidations using ceria-based materials

The Cr–Ce–O catalysts of different Cr content have been synthesised using co-precipitation or impregnation techniques, and tested in the oxidative dehydrogenation of isobutane. The Ce–-Cr–O system has already been found to be active and selective in this reaction at low temperatures around 270°C, with the selectivities to isobutene of about 60% at 10% isobutane conversion and a maximum yield of isobutene of about 8%. The total specific activity increases with the increase in the Cr content to a constant value observed for the samples prepared by precipitation at Cr/Ce ratio equal to 1, and those obtained by the impregnation at the Cr content of 10 At Cr nm −2 . The maximum specific activity does not depend considerably on the preparation technique, slightly higher yields are found, however, for the samples prepared by impregnation. Nevertheless, the co-precipitation technique leads to the less reproducible catalysts in which the potassium impurity may exert a poisoning effect.

B Grzybowska

Papers

Oxidative dehydrogenation of isobutane on Cr–Ce–O oxide:: I. Effect of the preparation method and of the Cr content