Heck zeolite support

Okumura, K., Nota, K., Yoshida, K. and Niwa, M. (2005) Catalytic performance and elution of Pd in the Heck reaction over zeolite supported Pd cluster catalyst. 

The Heck and Suzuki reactions have been catalyzed by other NPs such as RuNPs, including alumina-supported RuNPs [43c]. Hydroxyapatite-supported RuNPs were recently found to be efficient and recyclable catalysts for cis-dihydroxlahon and oxidative cleavage of alkenes [43dj. Supported RuNPs in the pores of mesoporous Al-MCM-41 materials were prepared by Hj reduchon of adsorbed [Ru(NH3),s], and the activity in benzene hydrogenabon was studied in the absence and presence of 330ppm H2S in H2. By comparison, zeolite-supported catalysts were found to be more efficient when H2S was present [43dj. 

Even so, undesirable effects, such as deactivation and loss of selectivity for heterogeneous catalysts, are unavoidable for some specific reactions. Hence, separation of homogeneous chemical catalysts by membrane retention or immobilization is emerging as a new application field, which in fact demands supports that combine thermal and mechanical stability with chemical resistance under reactive conditions. As a first approach, zeolite membranes can act as molecular filters able to retain the homogeneous catalyst, that is, as a simple separator. MFI zeolite membranes have been applied by Turlan et al. [347] in the Heck reaction to allow the permeation of... 

Inert metals such as platinum have been used as a support for palladium catalyst through a putative metal-metal bond resembling those present in metal clusters. There have been numerous reports concerning the use of various zeofites as support for palladium catalysts.f Palladium complexes entrapped into zeolite cages have been reported to be reusable catalyst for the Heck reaction, without the difficulties associated with cage diffusion problems. " ... 

Metal nanoparticles (MNPs) are excellent catalysts working under mild conditions either homogeneously or heterogenized on a solid support (zeolite, charcoal, nanotubes). For instance, Haruta discovered that AuNPs on Ti02 catalyze CO oxidation by O2 to CO2 under subambient conditions, with many applications. Alkene and arenes hydrogenation under ambient conditions and cross C-C bond formation (Suzuki, Sonogashira, Heck, Stille, Corriu-Kumada) with aryl halides are catalyzed by noble metal NPs (Ru, Rh, Pd or Pt). 

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