Monometallic catalytic data

Semi-batch, Non-preconditioned, Monometallic Catalytic Data... 

Supported gold nanoparticles have been used in sorbitol oxidation and compared with analogous Pd and Pt catalysts [41]. The catalytic data for the monometallic catalysts are reported in Table 13.8. Using carbon as a support, the reaction took... 

Only the monometallic complexes, RCORh(CO)4, Rli4(CO)i2, Rh6(CO)i6, HMn(CO)5 and Mn2(CO)io, were observed during the reaction. In addition, the kinetic data is consistent with a unicyclic catalytic reaction mechanism (i.e. mononuclear intermediates, equations 7 and 8). Product formation is most probably due to interactions between a rhodium-acyl intermediate, for example, RCORh(CO)4, and a hydrido-manganese species ... 

Thus, the experimental data show that the composition of catalytic systems does not influence the stereoregularity of the corresponding polymer fractions but only their relative content. Hence, the stereospecificity of the active centers of these catalysts is the same including the one-component catalyst TiCl2. This confirms the concepts on the monometallic character of AQ in the Ziegler-Natta catalysts. The possible existence of chiral titanium atoms on the titanium chloride surface was studied by Cossee and Arlman ... 

Intense research in the field of metal nanoparticles by chemists, physicists, and materials scientists is motivated by the search for new materials that hold novel physical (electronic, magnetic, optical) and chemical (catalytic) properties. Recently, the research on monometallic nanoparticles has been carried out in order to further miniaturize electronic devices [26-28] as well as to elucidate the fundamental question of how electronic properties of molecular aggregates evolve into novel properties with increasing size in this intermediate region between a molecule and a bulk [3,29-33]. Possible future applications include the areas of ultrafast communication and a large quantity of data storage [3,31,32,34]. 

The most active catalysts for methanol oxidation are presently based on bifunctional systems such as Pt-Ru. Yet the evaluation of a metal-support interaction would require the analysis of a simpler catalytic system (i.e., a monometallic catalyst) this would avoid the interference of all those aspects such as degree of alloying, changes in crystallographic parameters, chemical state of the promoting element, which significantly affect the activity, and thus a comprehensive interpretation of the data actually available. 

Fig. 6 Comparison of the catalytic performances of supported monometallic and bimetallic nanoalloy catalysts for the hydrogenation of LA to GVL, (a) Au and Pd system and (b) Ru and Pd system. Reaction conditions 7= 473 K pH2 = 40 bar 10 wt% LA in dioxane LAi to metal weight ratio = 1000. The data are adapted from the ref. 41.

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