Catalytic oxidative dehydrogenation

Most terpene-based citral (5) produced is based on the catalytic oxidative dehydrogenation of nerol (47) and geraniol (48), or by the Oppenauer oxidation of nerol and geraniol (123—125). 

Ziman et al. [Kinetika i Kataliz, 9 (117), 1968] have studied the kinetics of the catalytic oxidative dehydrogenation of various butene isomers to form 1,3-butadiene. Over a Bi-Mo catalyst the following reactions are important. 

Catalytic oxidative dehydrogenation of propane by N20 (ODHP) over Fe-zeolite catalysts represents a potential process for simultaneous functionalization of propane and utilization of N20 waste as an environmentally harmful gas. The assumed structure of highly active Fe-species is presented by iron ions balanced by negative framework charge, mostly populated at low Fe loadings. These isolated Fe sites are able to stabilize the atomic oxygen and prevent its recombination to a molecular form, and facilitate its transfer to a paraffin molecule [1], A major drawback of iron zeolites in ODHP with N20 is their deactivation by accumulated coke, leading to a rapid decrease of the propylene yield. 

In general, a catalytic reaction may be named by adding the adjective catalytic to the standard chemical term for the reaction, for example, catalytic hydrogenation (or, if clarity demands, heterogeneous catalytic hydrogenation), catalytic hydrodesulphurisation, catalytic oxidative dehydrogenation, catalytic stereospecific polymerisation. 

Fig. 59. Catalytic oxidative dehydrogenation of cyclohexene (O, surface catalysis) and oxidation of acetaldehyde ( , bulk-type II) the catalyst was HjPMonO supported on Si02. Masses catalyst 0.2 g for cyclohexene and 0.1 g for acetaldehyde. (From Ref. 327.)...

Quinones are effective cocatalysts for both homogeneous and supported POM-based catalytic oxidative dehydrogenation of alcohols... 

In the catalytic oxidative dehydrogenation of cyclohexene (OXD), both the flow of molecular oxygen in the system [33] and the presence of peroxides [34] in cyclohexene feed stock were found to be of prime importance as operational conditions. 

Catalytic Oxidative Dehydrogenation of Isobutane in a Pd Membrane Reactor... 

Oxidative dehydrogenation is kinetically fast and may relieve this limitation [6]. Previous research has shown that substantial amounts of olefins are formed by catalytic oxidative dehydrogenation in a high temperature (1000°C), short contact time (1-10 milliseconds) reactor for small alkanes [7, 8]. 

As a consumer of MIC, DuPont was concerned over the use and storage of this toxic material. Prior to Bhopal, we began research on a new process that would produce MIC from less hazardous materials and minimize its handling and storage. The proprietary (5) catalytic oxidative-dehydrogenation process, shown in equations 6-7 was discovered ... 

In the presence of copper(I) chloride in pyridine N-benzylidene-o-phenylenediamines 20 undergo catalytic oxidative dehydrogenation with 0 to afford 2-arylbenzimidazoles 21 or 2,2 -diaryl-1,1 -... 

Z. Chao and E. Ruckenstein, A comparison of catalytic oxidation dehydrogenation of ethane over mixed V-Mg oxides and over those prepared via a mesoporous V-Mg-0 pathway. Catalysis Letters 2003, 88, 147-154. 

Noble metal salts, for example, of Pd(II) or Pt(II), undergo reduction by primary and secondary alcohols inhomogeneous solution. Indeed, the ability of alcohols to reduce Pd(II) was described as early as 1828 by Berzelius, who showed that K2PdCl4 was reduced to palladium metal in an aqueous ethanolic solution [25]. The reaction involves a [3-hydride elimination from an alkoxymetal intermediate and is a commonly used method for the preparation of noble metal hydrides (Eq. (5.1)). In the presence of dioxygen this leads to catalytic oxidative dehydrogenation of the alcohol, for example, with palladium salts [26-30]. 

Lee, K.H., Yoon, Y.S., Ueda, W, and Moro-oka, Y. An evidence of active surface MoOx over MgMo04 for the catalytic oxidative dehydrogenation of propane. Catal. Lett. 1997, 46, 261. 

Citral can be prepared from both a- and (3-pinene. These are initially converted to geraniol as described in Sections 8.2.1 and 8.2.2, respectively, and then oxidized to citral using either catalytic oxidative dehydrogenation or Oppenauer oxidation [161-163]. The routes to citral used by the three main petrochemical suppliers, BASF, DSM, and Kuraray are described in Sections 8.2.S-8.2.5. 

MuUa, S. A. R., Buyevslmya, O. V., and Baems, M. A comparative study on noncata-lytic and catalytic oxidative dehydrogenation of ethane to ethylene. Appl. Catal, A 226, 73-78 (2002). 

Porous ceramic membranes have also found application in MRs as reactant distributors, particularly for catalytic oxidative dehydrogenation reactions where the intermediate or final products are more reactive towards oxygen than the original hydrocarbons, which limits reaction selectivity. As a result, total rather than partial oxidation of the original hydrocarbon is often achieved. Systems which can control the oxygen concentration along the reactor length, such as membranes by means of an MR, can increase the reaction selectivity towards the intermediate or final products (Coronas eta/., 1995). 

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