Colloidal catalysis

Spiro M and Freund P L 1983 Colloidal catalysis J. Chem. Soo. Faraday Trans. 1 1649-58... 

The development of dendrimer-encapsulated bimetallic nanoparticles has provided the interface with heterogeneous colloid catalysis, which is reviewed by B. Chandler and J. Gilbertson. In this field, dendrimers are being used to template and stabilize reduced colloidal particles in solution. The emphasis is placed on bimetallic particles and their application in a variety of fundamental catalytic transformations. 

Freund PL, Spiro M (1985) Colloidal catalysis the effect of sol size and concentration. J Phys Chem 89 1074... 

Spiro M, Freund PL (1983) Colloidal catalysis transport versus surface control. J Chem Soc, Faraday Trans 1 79 1649... 

Narayanan R, El-Sayed MA (2004) Effect of colloidal catalysis on the nanoparticle size distribution dendiimer-Pd vs PVP-Pd nanoparticles catalyzing the Suzuki coupling reaction. J Phys Chem B 108 8572... 

In addition to the synthesis of specific ligands and the resulting catalysts new ideas and concepts begin to combine with transition metal chemistry to open up new areas in homogeneous catalysis, like catalysis under supercritical conditions, colloidal catalysis , organometallic electrocatalysis and multi-metallic catalysis " ( cooperative catalysis ). 

Colloidal catalysts tend to precipitate in homogeneous processes [150]. This can be observed by the appearance of black metal residues in the system. This causes catalyst losses and decrease in the catalyst activity. Another significant problem in one-phase colloid catalysis is the recovery of the catalyst. Although in some cases the nanoparticle catalyst can be recycled several times by membrane filtration [151], most authors do not report on catalyst recycling. One possible solution is the use of two-phase systems. For example, aqueous Rh colloids were shown to be effective hydrogenation catalysts in a two-phase system, where the water immiscible phase was olefin [152]. The colloidal catalyst could be readily separated and recycled. It was shown that surfactants could be used to lower the interfacial tension to improve the efficiency of the two-phase system [153,154]. 

Monodisperse colloidal silica spheres with various surface coatings are of considerable interest to many fields, such as ceramics, colloids, catalysis, chromatography, and glass preparation. We are interested in these particles for their... 

R. Narayanan, M.A. El-Sayed, Effect of Colloidal Catalysis on the Nanoparticle Size Distribution Dendrimer-Pd vs. PVP-Pd Nanoparticles Catalyzing the Suzuki Coupling Reaction, Journal of Physical Chemistry B 108, 8572, 2004. 

Water-Soluble RuNPs for Investigation in Aqueous Colloidal Catalysis. 349... 

To pursue our work on mthenium nanoparticles, we have investigated their surface reactivity in colloidal catalysis via the hydrogenation of model substrates. In addition, RuNPs showed promising performances for the dehydrogenation of... 

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