Acrylic acid Catalyst characterization

Reactive compatibilization of engineering thermoplastic PET with PP through functionalization has been reported by Xanthos et al. [57]. Acrylic acid modified PP was used for compatibilization. Additives such as magnesium acetate and p-toluene sulfonic acid were evaluated as the catalyst for the potential interchange or esterification reaction that could occur in the melt. The blend characterization through scanning electron microscopy, IR spectroscopy, differential scanning calorimetry, and... 

A related study with a similar ruthenium catalyst led to the structural and NMR characterization of an intermediate that has the crucial Ru—C bond in place and also shares other features with the BEMAP-ruthenium diacetate mechanism.33 This mechanism, as summarized in Figure 5.4, shows the formation of a metal hydride prior to the complexation of the reactant. In contrast to the mechanism for acrylic acids shown on p. 378, the creation of the new stereocenter occurs at the stage of the addition of the second hydrogen. 

From a practical standpoint, it is of interest to devise a one-step synthesis of the catalyst. Since both reactions 2 and 3 are ligand substitution reactions, it is quite conceivable that both steps can be carried out at the same time. When we reacted [Ru(COD)Cl2]n with BINAP and sodium acetate in acetic acid, we indeed obtained Ru(BINAP)(OAc)2 in good yields (70-80%). Interestingly, when the reaction was carried out in the absence of sodium acetate, no Ru(BINAP)(OAe)2 was obtained. The product was a mixture of chloro-ruthenium-BINAP complexes. A 3ip NMR study revealed that the mixture contained a major species (3) (31P [ H] (CDCI3) Pi=70.9 ppm P2=58.3 ppm J = 52.5 Hz) which accounted for more than 50% of the ruthenium-phosphine complexes (Figure 2). These complexes appeared to be different from previously characterized and published Ru(BINAP) species (12,13). More interestingly, these mixed complexes were found to catalyze the asymmetric hydrogenation of 2-(6 -methoxy-2 -naphthyl)acrylic acid with excellent rates and enantioselectivities. 

V-Mo-P and V-Mo-Cs catalysts (251). The V-Mo-P catalysts are not selective therefore, at least two reaction pathways are important over this catalyst, and sufficient data were not available to characterize both pathways. The V-Mo-Cs catalysts showed low activity, and the adsorption of acrylic acid was irreversible, producing large errors in the determination of the heat effects of the reaction. 

The parameters cj), and cjij characterize the oxidation state of the catalyst. Because of the different reaction rates r, + rj and r, also different degrees of oxidation are assumed, which does not necessarily mean that specific sites for the oxidation of acrolein and acrylic acid exist. 

Blasco, T., Botella, P, Concepcion, P., et al. (2004). Selective Oxidation of Propane to Acrylic Acid on K-Doped MoVSbO Catalysts Catalyst Characterization and Catalytic Performance, /. Catal., 228, pp. 362-373. 

Bulk mixed metal oxide catalytic materials consist of multiple metal oxide components. Such mixed metal oxide catalysts find wide application as selective oxidation catalysts for the synthesis of chemical intermediates. For example, bulk iron-molybdate catalysts are employed in the selective oxidation of CH3OH to H2CO [122], bulk bismuth-molybdates are the catalysts of choice for selective oxidation of CH2=CHCH3 to acrolein (CH2=CHCHO) and its further oxidation to acrylic acid (CH2=CHCOOH) [123], selective ammoxidation of CH2=CHCH3 to acrylonitrile (CH2=CHCN) [123], and selective oxidation of linear CH3CH2CH2CH3 to cyclic maleic anhydride consisting of a flve-membered ring (four carbons and one O atom) [124]. The characterization of the surface... 

Despite the large number of techniques employed to characterize these two phases, little is known about how they eatalyze the propane transformation into acrylic acid and other products. Normally, propane activation should start with abstraction of methylene H, which is widely believed to occur on =0 center on the catalyst surface (Ml phase). This vanadyl group favors radical-type H-abstraction through its resonance form =0 o " +V -0 to form secondary... 

Cobalt. The rate law for carbonylation of Schiff bases, catalysed by Co2(CO)8, has been reported. Dicobalt octacarbonyl also catalyses reaction between aldehydes, for instance formaldehyde or acetaldehyde, amides, for example acetamide or benzamide, and carbon monoxide. The products are iV-acyl-amino-acids. The main product from the reaction of acetylene with carbon monoxide in the presence of CoH(CO)4 is ethyl acrylate. Characterization of the intermediates permits suggestions to be made as to the mechanism of this reaction. Initial reactions between the acetylene and two molecules of catalyst may give (106), in equilibrium with its isomer (107) the carbon monoxide inserts into the cobalt-carbon bonds of the latter. Further information about Coa(CO)8-catalysed hydro-formylation of acrylonitrile and of 3-methyl[3- H]hex-l-ene has led... 

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