An ionic liquid based on a cyclic guanidinium cation is an efficient medium for the selective oxidation of benzyl alcohols

A novel room temperature ionic liquid (RTIL) has been prepared containing a cyclic hexaalkylguanidinium cation. The selective oxidation of a series of substituted benzyl alcohols has been carried out in it, with sodium hypochlorite as the oxidant. The RTIL acts as both phase transfer catalyst (PTC) and solvent. The ionic liquid could be recycled after extraction of the benzaldehyde product with ether.

Selective oxidation of m-phenoxytoluene to m-phenoxybenzaldehyde with methanol as an additive in acetic acid

With addition of methanol in acetic acid solvent, m-phenoxytoluene could be oxidized to m-phenoxybenzaldehyde selectively by a cobalt bromide catalyst. Paratemters such as the ratio of Co/Br and the reaction time of m-phenoxytoluene oxidation as well as visible spectra of cobalt bromide in acetic acid/methanol solvents, were also investigated. Addition of methanol caused the oxidation of aldehydes to proceed more slowly than it did solely in acetic acid solvent. The decrease of cobaltous-multibromides in acetic acid/methanol solvents was responsible for the improvement in the selective oxidation of m-phenoxytoluene. (C) 1999 Elsevier Science B.V. All rights reserved.

Development and application of oxygen permeable membrane in selective oxidation of light alkanes

In this paper, oxygen permeable membrane used in membrane reactor for selective oxidation of alkanes will be discussed in detail. The recent developments for the membrane materials will be presented, and the strategy for the selection of the membrane materials will be outlined. The main applications of oxygen permeable membrane in selective oxidation of light alkanes will be summarized, which includes partial oxidation of methane (POM) to syngas and partial oxidation of heptane (POH) to produce H-2, oxidative coupling of methane (OCM) to C-2, oxidative dehydrogenation of ethane (ODE) to ethylene and oxidative dehydrogenation of propane (ODP) to propylene. Achievements for the membrane material developments and selective oxidation of light alkanes in membrane reactor in our group are highlighted.

Effect of diffusion barrier on the high-temperature oxidation behavior of thermal barrier coatings

A selective oxidation technique has been applied to form a diffusion barrier on the Ni-based superalloy substrate by heating the substrate with electron beam of the electron beam-physical vapor deposition (EB-PVD) facility. The interdiffusion behavior, cross-sectional morphology, isothermal and cyclic oxidations were studied for thermal barrier coatings (TBCs) with and without diffusion barrier.