Bimetallic catalysts configuration

Kinetic, spectroscopic, and enantioselectivity data provided strong evidence for a mechanism involving bimetallic catalysis. The configurational outcome depends upon the face selectivity of the enol approaching the Michael acceptor in 59 (Fig. 32). To differentiate between the enantiotopic faces, the catalyst has thus... 

Metal dispersions were observed to decrease as the concentration of Ru was Increased. This same trend was observed for the Ru-Rh catalysts and was in marked contrast to observations on silica-supported Ft-Ru catalysts W. In this case a large Increase in dispersion was obtained as a result of bimetallic clustering in the cherry model configuration. 

Replacement of 10 mol% cadmium chloride catalyst with complex 8 resulted in an increase in the reaction yield and rate, highlighting the crucial roles of ligand configuration and the cooperative bimetallic catalytic effect as operative for 8. With the optimal conditions already established, the reaction scope was also investigated, by the synthesis of a series of C-N coupling products in good to excellent yields (Table 17.1, entries 1-5). 

PdCo PdPt/C) [163,164] and PdsPt/C [165] were found to demonstrate better alcohol tolerance and comparable and even better electrocatalytic performance than commercial Pt/C. A superior ORR activity and methanol tolerance as compared to commercial Pt/C and Pd/C catalysts have also been reported with a novel nanotubular mesoporous PdCu bimetallic nanocomposite comprising interconnected alloy nanoparticles with sizes around 3nm. The improved performance is related to the special structural configuration of the catalyst [166]. 

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