Newly Developed Applications of DENs in Catalysis

DENs have been applied in many homogeneous and heterogeneous catalytic reactions and show excellent activity and selectivity. DENs have also been used in elec-trocatalytic reactions. A recent review article covers most of these reactions [42], In this section, we will only focus on several recent developments of using DENs in catalysis. 

When DENs were used as catalysts in solution. Crooks et al. found that the presence of PAMAM dendrimers doesn t block the metal surface [24, 96, 97], Once DENs were loaded onto oxides, it was proposed that the PAMAM dendrimer would collapse onto the surface of the metal nanoparticles and block their active sites [98]. However, Somoqai et al. found that it is not necessary to perform the high-temperature oxidation and reduction treatments for mesoporous silica (SBA-15) supported Rh and Pt DENs for them to show good activity for the ethylene hydrogenation reaction, as shown in Fig. 4.9 [52]. 

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