Catalyst supports polyaniline

Zabrodskii, A.G. et ah. Carbon supported polyaniline as anode catalyst pathway to platinum-free fuel cells, Technol. Phys. Lett., 32, 758, 2006. 

B. Rajesh, K. R. Thampi, J. M. Bonard, H. J. Mathieu, N. Xanthopoulos, and B. Viswanathand, Nanostructured conducting polyaniline tubules as catalyst support for Pt particles for possible fuel cell applications, Electrochem. Solid-State Lett., 7, A404-A407 (2004). 

Similar synergic Au-Pd interactions were reported for bimetallic Au-Pd catalysts supported on polyaniline (PANI) [79] for benzyl alcohol oxidation. Here, the colloidal preparative route provided a narrow particle size distribution ( 3nm) with a Pd-rich shell encapsulating an Au-rich core. In this instance, the optimal composition was Au Pd =1 9. Benzyl alcohol oxidation has likewise been studied over an Au-Pd/Ti02 catalyst in which the deposition-precipitation method was used to improve the particle size distribution and activity versus wet impregnation [80]. In contrast, liquid-phase oxidation of cinnamyl, benzylic, octenol, and octenal... 

The polarization curves in Fig. 2 show that polyaniline is a more effective catalyst support than its composite with PSS, and that its effectiveness can be enhanced considerably by addition of a proton conductor (Nation) to the catalyst layer. The beneficial effect of Nation here is not surprising because polyaniline is not likely to be a good proton conductor. 

Several other solid acid nitrates, supported polyaniline, and very recently, the use of ionic liquids as efficient catalysts have additionally been reported (05JMCCF2249,01TL9285). 

Palaniappan S, Shekhar RC (2004) Synthesis of 7-Hydroxy-4-methyl coumarin using polyaniline supported acid catalyst. J Mol Catal A Chem 209 117-124... 

Polyaniline-supported Co(II) catalyst 41 was used to catalyze the epoxidation of various alkenes under oxygen atmosphere at ambient temperature.61 63 One report61 described a synthesis of a-hydroxy- 3-aminopyrrolidine amides as potential HIV protease inhibitors (Scheme 1). In this synthesis, catalyst 41 also mediated epoxide ring opening of the epoxide intermediate by an aniline to afford the desired product. 

Das, B. C. Iqbal,J. Polyaniline Supported Cobalt(II)-Salen Catalyst One-Pot Synthesis of [3-Phenylisoserine Derivatives from Cinnamoyl Amide, Tetrahedron Lett. 1997, 38, 2903. 

Epoxidation. The cooxidation of alkenes (including 1-tridecene, stilbene, and an A-substituted cinnamide) with isopropanol by oxygen at room temperature is mediated by polyaniline-supported Co(OAc)j. The catalyst is readily recovered by filtration. 

Interesting supports are the polymeric materials, notwithstanding their thermal instability at high temperatures. In the electrocatalysis field, the use of polypyrrole, polythiophene and polyaniline as heteropolyanion supports was reported [2]. The catalytically active species were introduced, in this case, via electrochemical polymerization. Hasik et al. [3] studied the behavior of polyaniline supported tungstophosphoric acid in the isopropanol decomposition reaction. The authors established that a HPA molecular dispersion can be attained via a protonation reaction. The different behavior of the supported catalysts with respect to bulk acid, namely, predominantly redox activity versus acid-base activity, was attributed to that effect. 

The applications reported for polymer-supported, soluble oxidation catalysts are the use of poly(vinylbenzyl)trimethylammonium chloride for the autooxidation of 2,6-di-tert-butylphenol [8], of copper polyaniline nanocomposites for the Wacker oxidation reaction [9], of cationic polymers containing cobalt(II) phthalocyanate for the autooxidation of 2-mercaptoethanol [10] and oxidation of olefins [11], of polymer-bound phthalocyanines for oxidative decomposition of polychlorophenols [12], and of a norbornene-based polymer with polymer-fixed manganese(IV) complexes for the catalytic oxidation of alkanes [13], Noncatalytic processes can also be found, such as the use of soluble polystyrene-based sulfoxide reagents for Swern oxidation [14], The reactions listed above will be described in more detail in the following paragraphs. 

B. J. Gallon, R. W. Kojima, R. B. Kaner, and P. L. Diaconescu, Palladium nanoparticles supported on polyaniline nanofibers as a semi-heterogeneous catalyst in water, Angew. Chem. Int Ed., 46, 7251-7254 (2007). 

H. Ding, G. Wang, M. Yang, Y. Luan, Y. Wang, and X. Yao, Novel sea urchin-hke polyaniline microspheres-supported molybdenum catalyst Preparation, characteristic and functionality, J. Mol Catal A Chem., 308, 25-31 (2009). 

M. Hasik, A. Derlinkiewicz, M. Choezynski, S. Quillard, and A. Pron, Polyaniline containing palladium - new conjugated polymer supported catalysts, Synth. Met., 84, 93-94 (1997). 

Kantam, M. L., Roy, M., Roya, S., Sreedhara, B. and De, R. L. 2008. Polyaniline supported Cul An efficient catalyst for C-N bond formation by N-arylation of iV(//)-heterocycles and benzyl amines with aryl halides and arylboronic acids, and aza-Michael reactions of amines with activated aUcenes. Catal. Commun. 9(13) 2226-2230. 

---